SF3 1 General

Question 1

Tract of Thorel

Answer 1

Another name for Inferior Internodal Tract

Question 2

Heat Stroke

Answer 2

Develops when body temperature rises beyond 105-108 F

Symptoms:

• Dizziness
• Abdominal distress
• Vomiting
• Delirium
• Loss of consciousness
• Circulatory shock (loss of fluids/electrolytes)

Question 3

Mechanical connections between cardiac muscle cells

Answer 3

keep cells together during contraction. Have adherens junctions and desmosomes

Question 4

Endothelial-derived Hyperpolarizing Factor (EDHF)

Answer 4

Vasodilator

Hyperpolarize smooth muscle, leading to relaxation

Question 5

Mean Systemic Filling Pressure (PSF)

Answer 5

Equalized pressure throughout cardiovascular system if heart was hypothetically stopped. Dependent on Blood Volume and Vascular Compliance

Question 6

(ECG) Hyperkalemia

Answer 6

Abnormality of Myocyte Repolarization.

• Tall, peaked T wave

Question 7

Phases of Cardiac Cycle associated with Ventricular Diastole

Answer 7

Phase 5-7, 1

Question 8

Foramen Secundum defect

Answer 8

(Atrial Septal Defect - ASD) Most common ASD. Large opening between the Right and Left Atria, as a result of…

1) Excessive resorption of Septum Primum OR
2) Insufficient development of Septum Secundum

Blood flows from L to R Atrium due to increase blood pressure in left atrium

Question 9

Parasympathetics effect on Lungs

Answer 9

1) constrict respiratory passageways
2) vasodilation
3) increase mucous secretion

Question 10

Left Coronary Artery

Answer 10

Origin is Aortic Sinus of Left Cusp of Aortic Valve.

Supplies:

1) Most of L Atrium
2) L Ventricle
3) Anterior 2/3 of Interventricular Septum
4) Atrioventricular Bundles

Question 11

Pulse Pressure

Answer 11

Difference between systolic and diastolic pressure

PP = PS - PD = SV / C

Question 12

Locations of Turbulent Flow

Answer 12

1) Distal to stenotic vessels/valves
2) Large arterial branch points
3) Ascending Aorta at high cardiac ejection velocities

Question 13

Foramen Primum

Answer 13

Temporary space between free edge of growing septum primum and AV septum

Question 14

Location of SA Node

Answer 14

In the wall of the Right Atrium, in superior part of Crista Terminalis

Question 15

(Fast Response Action Potential Receptors) Phase 2

Answer 15

Calcium influx through L-type calcium channel. Some potassium efflux through slow delayed rectifier channel

“plateaued”

Question 16

Branches of Aortic Arch (Right to Left)

Answer 16

1) Brachiocephalic Trunk (largest)
2) Left Common Carotid Artery
3) Left Subclavian Artery

Question 17

Area where systolic blood restriction in Coronary Arteries is most pronounced

Answer 17

Left ventricle (higher contractility)

Question 18

Limbus

Answer 18

thick upper margin of the Fossa Ovalis

Question 19

Second Heart Sound (S2)

Answer 19

Closure of Semilunar Valves at end of Ventricular Systole.

Aortic Valve precedes Pulmonic valve. Sound combined into 1 during expiration. separates in inspiration “Physiological splitting of S2”.

Question 20

(Cardiac Cycle) Phase 7: Reduced Filling (Diastasis)

Answer 20

Rate of passive fillings slows and plateaus. Ventricles become less compliant as they fill. Increase in ventricular volume causes a small and gradual increase in pressure.

Aortic/Pulmonary pressure drops as blood circulates

Question 21

External Intercostal Muscle

Answer 21

Extends posterior from tubercle of rib to junction of rib with its costal cartilage. Moves rib superiorly (most active during inspiration)

Question 22

Greater Splanchnic Nerves

Answer 22

Arise from 5-9/10 thoracic ganglia. Descend across vertebral bodies medially. Pass into abdomen through Crus of the Diaphragm.

End in Celiac Ganglion

Question 23

Location of Cell Bodies of Parasympathetic Fibers affecting Heart

Answer 23

Dorsal Vagal Nucleus and Nucleus Ambiguus (medulla)

Question 24

Cardiopulmonary Changes at Birth

Answer 24

1) Opening of pulmonary circulation
2) Closure of placental circulation
3) closure of ductus venosus
4) foramen ovale closes
5) closure of ductus arteriosus

Question 25

Artery coursing with Phrenic Nerve to supply pericardium and diaphragm

Answer 25

Pericardiophrenic Artery (and accompanying vein)

Question 26

Hydrothorax

Answer 26

Excessive serous fluid (Pleura). Result of cardiac failure and congestion of lungs.

Question 27

Crista Terminalis

Answer 27

Vertical ridge dividing right atrium into two

Question 28

Causes activation of Ryanodine Receptor (RYR)

Answer 28

Increase in intracellular Ca2+

Question 29

Coronary Artery Bypass Graft

Answer 29

Occluded artery is replaced by a vein (usually Great Saphenous Vein). Grafted from Aorta to part of coronary artery not occluded. Internal Thoracic Artery can be used to supply heart too. Stripped off Anterior Thoracic Wall but still attached to Subclavian Artery. Attach to non-occluded pt of artery

Question 30

Meaning of QRS Complex

Answer 30

Ventricular depolarization

Question 31

Joint between Sternal Body and Manubrium

Answer 31

Symphysis joint, allowing for little movement

Question 32

σ = 0

Answer 32

Capillary freely permeable

Question 33

Channel releasing Ca2+ from SR in smooth muscle

Answer 33

Inositol 1,4-5-Triphosphate Channel

Question 34

Right Para-Tracheal Stripe

Answer 34

Thin white stripe at the right edge of the trachea. Created by air of low density on either side of the tracheal wall. Normally < 3mm thick, any thicker may be mass or enlarged lymph node. Right side not well defined

Question 35

Form Definitive Right Subclavian Artery

Answer 35

1) Right Aortic Arch 4 2) Right Dorsal Aorta 3) Right 7th Intersegmental Artery

Question 36

Fenestrated Capillaries

Answer 36

Perforations in the endothelium. Found in: exocrine glands, renal glomeruli, and intestinal mucosa

Question 37

Capillary Plasma Oncotic Pressure (πc)

Answer 37

Determined by proteins in capillary. Albumin generates about 70% of it. Rest is globulins and fibrinogen

Question 38

Left Ventricle is lined by Trabeculae Carnae except..

Answer 38

Smooth-walled Aortic Vestibule under Aortic Orifice

Question 39

Factors Affecting Afterload

Answer 39

1) Vascular Resistance to Blood Flow (small arteries/arterioles major source) 2) Decreased compliance of ventricles/great vessels 3) Pathological issues (ex: valvular stenosis) 4) drugs

Question 40

Cycloxygenase Inhibitors

Answer 40

Include Aspirin and others. Reduce fever by inhibiting Prostaglanding synthesis

Question 41

Primary Neural Regulatory Areas of Cardiovascular Function

Answer 41

Reticular Formation of Ventrolateral Medulla and Lower Third of the Pons

Question 42

Polycythemia

Answer 42

Elevated hematocrit

Question 43

ABCDEF System

Answer 43

* Airway * Bones and Soft Tissue * Cardiac and Mediastinum * Diaphragm * Effusions * Fields (Lungs)

Question 44

Small Cardiac Vein

Answer 44

Tributary of Coronary Sinus. Right anterior-inferior margin of right ventricle. Drains area supplied by Marginal Artery

Question 45

Aortic Arches that degenerate

Answer 45

1, 2, and 5 | Exception: 1 forms part of maxillary, 2 part of stapedial artery

Question 46

Sensory fibers of heart (where do they enter CNS)

Answer 46

Enter spinal cord at T1-T4 on left side

Question 47

Afterload

Answer 47

Resistance that ventricle must overcome to eject blood into vasculature.

Question 48

Structures at level of Sternal Angle (7)

Answer 48

1) Costal Cartilage of Rib 2 2) Intervertebral Disc between T4-T5 3) Line between Superior and Inferior Mediastina 4) Superior extent of fibrous pericardium 5) Trachea division into Main Bronchi 6) Azygous Vein -> Superior Vena Cava 7) Bifurcation of Pulmonary Trunk into Right/Left Pulmonary Arteries

Question 49

Anteroapical Myocardial Infarction (Leads and Typical Artery)

Answer 49

Leads V3-V5 Left Anterior Descending Coronary Artery (distal)

Question 50

Electrical connections between cardiac muscle cells

Answer 50

Allow action potential propagation via gap junctions

Question 51

β2-adrenoreceptors

Answer 51

Cause vasodilation of vessels

Question 52

Brugada Syndrome

Answer 52

Characterized by right bundle branch block (RBBB) and ST segment elevation in right precordial leads. Majority fast sodium channel loss-of-function mutations.

Question 53

Xiphoid Process

Answer 53

most inferior portion of sternum; first cartilagenous then becomes ossified in adults

Question 54

Conditions causing hypoeffective heart

Answer 54

1) Decreased contractility 2) inefficient pumping (valvular disease or septal defect) 3) Reduced filling (ex: pericardial effusion and cardiac tamponade) 4) Increased afterload (ex: hypertension) 5) Cardiac Hypoxia 6) Abnormal heart rhythm

Question 55

Subcostal Muscles

Answer 55

Fibers in same direction as Internal/Innermost Intercostal muscles. Span 1-2 intercostal spaces. More numerous in lower posterior thoracic wall

Question 56

Structures Visible in Aortopulmonary Window Level

Answer 56

1) Aortopulmonary window 2) Ascending Aorta 3) Descending Aorta 4) Superior Vena Cava 5) (possibly) uppermost aspect of the L Pulmonary Artery 6) Trachea bifurcation

Question 57

Tetralogy of Fallot

Answer 57

Four Defects (Mnemonic: "IHOP") 1) Interventricular Septal Defect 2) Hypertrophy of R Ventricle (increased pressure on right) 3) Over-Riding Aorta (Large aorta arising above septal defect) 4) Pulmonary Stenosis Result of unequal division of Bulbus Cordis by Aorticopulmonary Septum. Presents with Cyanosis

Question 58

Sustained Muscle Contraction (Skeletal Muscle Perfusion)

Answer 58

Mean flow decreases during this period. Afterwards, postcontraction hyperemic response

Question 59

(ECG) Left Ventricular Hypertrophy

Answer 59

* Leads overlying L Ventricle (V5, V6, I, and aVL) show taller R waves * Leads on other side (V1, V2) show deeper S waves than normal

Question 60

Middle Cardiac Vein

Answer 60

Tributary of Coronary Sinus. In posterior part of Interventricular Sulcus. Drains areas supplied by Posterior Interventricular Artery

Question 61

(ECG) Junctional Escape Rhythm

Answer 61

Arise form AV Node or Proximal Bundle of His * Normal QRS * No P wave * rate of 40-60 bpm

Question 62

First Heart Sound (S1)

Answer 62

From closure of the AV valves. Mitral valve closes before tricuspid but it's too quick to distinguish.

Question 63

Persistent Truncus Arteriosus

Answer 63

Failure of development of Bulbar/Truncal Ridges. Presents as single arterial trunk giving rise to both Pulmonary Trunk and Ascending Aorta. Usually accompanied by defect in IV Septum. No bulbar ridges to fuse with AV Septum. Infant presents with Cyanosis

Question 64

Native Pacemaker

Answer 64

SA Node. 60-100 bpm at rest

Question 65

Starling Forces Governing Fluid Filtration/Reabsorption

Answer 65

1) Capillary Pressure (Pc) 2) Interstitial Fluid Pressure (Pi) 3) Capillary Plasma Colloid Osmotic Pressure (πc) 4) Interstitial Fluid Colloid Osmotic Pressure (πi)

Question 66

Hemothorax

Answer 66

Blood in pleural cavity

Question 67

(ECG) Second Degree AV Conduction System Block, Mobitz Type II

Answer 67

* Sudden, intermittent loss of AV conduction * Block may persist for two or more beats * Caused by conduction block BEYOND AV node (His/Purkinje) * QRS often widened * Indicates severe disease

Question 68

Calculating Mean QRS Axis

Answer 68

1) If Lead I/II predominantly upright, you're gucci. If not.. 2) Inspect 6 LIMB LEADS for most isoelectric QRS. Mean axis is perpendicular to this lead 3) if perpendicular lead is primarily upward, it's positive end. If downward, it's the negative end

Question 69

Common Atrium (Trilocular Biventriculare)

Answer 69

(Atrial Septal Defect - ASD) Total lack of development of Atrial Septum. Always alongside another serious heart defect

Question 70

Fossa Ovalis

Answer 70

Thin-walled oval depression in posterior wall of right atrium. Successor of the Foramen Ovale in development. Thick upper margin of fossa called Limbus

Question 71

Postductal Coarctation of Aorta

Answer 71

Narrowing of the Aorta inferior to the entrance of the Ductus Arteriosus. For blood to reach the structures supplied by the aorta inferior to narrowing, collateral (anastamoses) circulation develops at two locations: 1) Anterior Intercostal Branches of the Internal Thoracic Artery and the Posterior Intercostal Arteries of the Aorta 2) Superior Epigastric Artery and Inferior Epigastric Artery

Question 72

Premature Closure of Foramen Ovale

Answer 72

(Atrial Septal Defect - ASD) Happens prenatally. Underdevelopment of the left side heart. Hypertrophy of right. Death shortly after birth

Question 73

Components of Definitive Right Ventricle

Answer 73

1) Trabeculated Part (majority) - from Primitive Ventricle | 2) Smooth Upper Part (Conus Arteriosus) drived from Bulbus Cordis

Question 74

Anterior Mediastinum

Answer 74

Between the pericardium and sternum

Question 75

Right Lymphatic Duct

Answer 75

Right side of root of neck. Drains into Right Brachiocephalic vein. Receives: 1) Right Subclavian Lymph Trunk 2) Right Bronchomediastinal Lymph Trunk 3) Right Jugular Lymph Trunk Drains: 1) Right side head/neck 2) right upper limb 3) right lung 4) skin of right thoracic wall

Question 76

Reactive Hyperemia

Answer 76

Transient increase in organ blood flow after brief period of ischemia, usually produced by temporary arterial occlusion. During occlusion, tissue hypoxia and vasoactive metabolites dilate arterioles.

Question 77

Currents of Injury Mechanism

Answer 77

Can produce deviation of ST segment. Believed to be caused by injured myocardial cells adjacent to infarct zone. Produce abnormal diastolic or systolic currents

Question 78

Paired Lateral Splanchnic Arteries

Answer 78

form renal, suprarenal, and gonadal arteries

Question 79

(ECG) Ventricular Escape Rhythm

Answer 79

Ventricles depolarized from distal point in conduction system * Rate of 15-40 bpm * Widened QRS complex * No P Wave * Have R' second upward spike

Question 80

Myogenic Regulatory Mechanism in small arteries/arterioles

Answer 80

Sudden expansion of vessel lumen leads to smooth muscle contraction. Reverse also true

Question 81

Costodiaphragmatic Recess

Answer 81

Founds on both sides. Slit-like space of reflection of costal pleura onto diaphragmatic pleura. Lungs do not enter it with normal inspiration

Question 82

Muscle layers where Intercostal Neurovascular Bundle found

Answer 82

In between Internal and Innermost Intercostal Muscle layers

Question 83

Preganglionic Neuronal Bodies of Sympathetic Division (LocatioN)

Answer 83

Lateral horns of spinal gray matter T1-T12, L1-L3

Question 84

False Ribs

Answer 84

Do not articulate with sternum. Ribs 8-12

Question 85

(Cardiac Cycle) Phase 6: Rapid Filling

Answer 85

AV valve opens when pressure in relaxing ventricles falls below that of the atria. Rapid filling ensues because (a) venous return has filled Atrium and (b) AV valve resistance is very low. Increase in ventricular volume.

Question 86

Autoregulatory Range

Answer 86

Range of pressures over which vessel blood flow barely changes

Question 87

Pulmonary Ligament

Answer 87

2 layers of pleura in contact with each other inferior to root of lung. No major structures in it.

Question 88

Endothoracic Fascia

Answer 88

Separates parietal pleura from the ribs/intercostal muscles

Question 89

Meaning of T Wave

Answer 89

Ventricular Repolarization

Question 90

Left atrium entirely smooth-walled except..

Answer 90

Lining of Left Auricle (contains pectinate muscles)

Question 91

Stimulates shivering

Answer 91

hypothalamus

Question 92

Afterdepolarizations

Answer 92

First action potential leads to oscillations of membrane voltage

Question 93

Normal response of Coronary Arteries to increase heart rate / metabolic consumption

Answer 93

Dilate. Vasodilator reserve becomes limited if they're diseased however. This can lead to myocardial ischemia and anginal pain.

Question 94

Radiological indication of Pneumothorax

Answer 94

Slight shift of the heart and mediastinum toward the left indicates a tension pneumothorax

Question 95

(Jugular Venous Pulse Graph) X descent

Answer 95

downward component of an A Wave. Happens from pressure decline of atrial relaxation

Question 96

Loss-of-Function Mutation

Answer 96

Results in reduced or abolished protein function

Question 97

Myosin Isoform in Smooth Muscle

Answer 97

Slower ATPase activity than its counterpart in skeletal muscle

Question 98

(Cardiac Cycle) Phase 1: Atrial Systole

Answer 98

Initialized by spread of depolarization in atrium. Causes transient rise in Left Atrial Pressure. At rest, contribution to ventricular filling only 10-15%. Greater contribution during strain (decreased interval from increased heart rate means less time for passive filling). End of Atrial Systole coincides with end of Ventricular Diastole. End-Diastolic Volume (EDV).

Question 99

Function of Transversus Thoracis

Answer 99

Depress costal cartilages

Question 100

Hypertrophic Cardiomyopathy

Answer 100

One part of heart thicker than other parts. Most common monogenic cardiac disorder. Most cases genetic. It's AUTOSOMAL DOMINANT. Predominant mutations: a) myosin heavy chain b) myosin binding protein Can result in myofibril disarray. Clinical symptoms range from asymptomatic to heart failure, exercise intolerance, and chest pain. Symptoms with aging due to loss of left ventricular function. Increased risk for sudden cardiac death because of arrhythmias.

Question 101

Fibrous Skeleton of the Heart

Answer 101

Fibrous rings of connecting tissue. On right-side, surrounds orifice of pulmonary trunk and R Atrioventricular orifice. On left, orifice of ascending aorta and L Atrioventricular orifice

Question 102

Methods to calculate Heart Rate from ECG

Answer 102

1) HR = 60/RR 2) "Count-Off" Method 3) Count # of complexes in 3 or 6 seconds

Question 103

Ductus Venosus

Answer 103

Shunts placental blood directly to IVC

Question 104

Lusitropy

Answer 104

Relaxation of myocardium

Question 105

ST Segment

Answer 105

Isoelectric period and depolarized ventricles. End of S wave to beginning of T wave.

Question 106

Dextrocardia

Answer 106

Heart located on right side of Thorax. Due to ventricle and bulbus cordis bending to wrong side. Relatively uncommon

Question 107

Capillary-like vessels blood passes through in liver

Answer 107

Liver Sinusoids

Question 108

Normal Duration of QT Interval

Answer 108

0.20-0.40 seconds 5-10 boxes

Question 109

Anterior/Posterior Intercostal Arteries - which is larger

Answer 109

Posterior

Question 110

(ECG) Ventricular Tachycardia

Answer 110

* Widened QRS complex (>0.12 s) * Rate of 100-200 bpm (sometimes faster) Two Types: Monomorphic and Polymorphic VT

Question 111

Filtration Constant (Kf)

Answer 111

Permeability of capillary to fluid. Increased by histamine

Question 112

Dromotropy

Answer 112

Conduction velocity

Question 113

High Pulmonary Vasculature Resistance in Fetus

Answer 113

Only small amounts of Right Ventricular output enters pulmonary circulation. Lungs non-functional. Remainder crosses over to Descending Aorta in the Ductus Arteriosus Caused by: 1) Collapsed Lung 2) Hypoxic Vasoconstriction

Question 114

Bradykinin

Answer 114

Formed in the blood and tissue fluids of some organs. Released during tissue inflammation or similar physical/chemical effects. Role in blood flow regulation in skin and salivary and gastrointestinal glands. Causes arteriolar dilation and increased capillary permeability.

Question 115

Sources of blood drained through Azygous Vein

Answer 115

1) Right Thoracic Wall (Posterior Intercostal Veins) 2) Left Thoracic Wall (Hemiazygous/Accessory Hemiazygous Veins) 3) Esophagus (Esophageal Veins), Lung Tissue (Bronchial Veins), and Vetrebral Column (Vertebral Venous Plexus)

Question 116

Coursing of Left Anterior Fascicle

Answer 116

Runs through Anterior, Superior, and Lateral Left Ventricle

Question 117

Destination of Excitatory Interneurons from Nucleus Tractus Solitarus

Answer 117

Vagal Neurons in Dorsal Vagal Nucleus and Nucleus Ambiguus

Question 118

Myocardium formation in development

Answer 118

Forms from Splanchnic mesoderm surrounding the single heart tube

Question 119

Fick's First Law of Diffusion

Answer 119

Js= (D)(A)(ΔC) / (ΔX) ``` Js: Flux (mol/s) D: Diffusion const. of barrier (substance-dependent) A: Surface Area ΔC: concentration gradient ΔX: diffusion distance ```

Question 120

Lesser Splanchnic Nerves

Answer 120

Arise from 9/10 or 10/11 Thoracic Ganglia. End in Aorticorenal Ganglion

Question 121

Continuous with Superior Mediastinum

Answer 121

Inferior Mediastinum

Question 122

Pericardial Cavity

Answer 122

Potential space between serious parietal and visceral pericardia.

Question 123

Vasodilatory Theory

Answer 123

Local regulatory theory. Greater metabolic function leads to formation of vasodilatory substances. Blood flow increases to area of increased metabolism.

Question 124

Firing Rate of Cells of Purkinje System

Answer 124

30-40 bpm

Question 125

Capillary Recruitment

Answer 125

Increased recruitment of perfused capillaries during skeletal muscle contraction and Active Hyperemia

Question 126

Ejection Fraction

Answer 126

Fraction of End-Diastolic Volume that is ejected from ventricle during systole. Normally greater than 55% EF = (SV)/(EDV) * 100

Question 127

(ECG) Hypocalcemia

Answer 127

Abnormality of Myocyte Repolarization. * prolonged QT interval

Question 128

Atrial Natriuretic Peptide (ANP)

Answer 128

Released from Cardiac Atrial Tissue in response to: 1) Atrial Distention 2) Sympathetic Stimulation 3) Increased Angiotensin II 4) Endothelin Counter-regulatory mechanism for Renin-Angiotensin-Aldosterone system

Question 129

Left Anterior Descending (or Anterior Interventricular Branch)

Answer 129

From Left Coronary Artery. Runs inferior to Anterior interventricular sulcus toward apex. Can continue into Posterior Interventricular Sulcus. May anastomose with Post. Interventricular Branch there. Supplies: 1) Both Ventricles 2) Anterior 2/3 of Interventricular Septum

Question 130

Artificial Pacemaker

Answer 130

Pacemaker attached to chest wall and an electrical lead is fed through the Cephalic or Subclavian Vein. Tip of lead implanted into Right Ventricle, allowing for synchronized contraction

Question 131

Inferior (Diaphragmatic) Surface of Heart

Answer 131

Right and left ventricles

Question 132

Sternal Angle (of Louis)

Answer 132

Joint between the sternal body and manubrium

Question 133

Left Superior Vena Cava

Answer 133

Terminal part of left anterior cardinal vein that normally degenerates persists but terminal part of right anterior cardinal vein degenerates.

Question 134

Gain-of-Function Mutation

Answer 134

Results in new or enhanced activity of a protein

Question 135

Coronary Sinus

Answer 135

Large vein in posterior part of Atrioventricular Sulcus. Receives most of heart's blood via tributaries. Opens into Right Atrium superior to IVC. Rudimentary, single cusp valve. Three Tributaries: Great Cardiac Vein, Middle Cardiac Vein, and Small Cardiac Vein

Question 136

Two layers of Serous Pericardium

Answer 136

Parietal and Visceral

Question 137

Why are Ribs 11/12 not palpable?

Answer 137

Buried in abdominal wall musculature

Question 138

Chordae Tendinae

Answer 138

Small, thin cords which attach to free margins of cusps to papillary muscles on ventricular walls. Function: papillary muscles contract, keep Chordae Tendinae taut to prevent backflow

Question 139

Azygous Vein

Answer 139

Anterior right side of Thoracic Vertebrae. Superior continuation of Right Ascending Lumbar Vein. Drains blood from the Right Posterolateral Abdominal Wall into Inferior Vena Cava. Enters Poster Mediastinum passing through Aortic Hiatus of Diaphragm. Drains into Super Vena Cava

Question 140

Normal Range of Mean Electrical Axis

Answer 140

(-30) - (+90)

Question 141

Contractility (Inotropy)

Answer 141

Intrinsic property of myocardium accounting for changes in contraction strength when Preload/Afterload are held constant

Question 142

Angioplasty

Answer 142

Balloon catheter inserted into Ascending Aorta and into occluded coronary artery. Balloon expanded using dilute contrast media. Point is to widen them.

Question 143

Pneumothorax

Answer 143

Air enters pleural cavity and collapses lung via external or internal sources

Question 144

Vagus Nerve Effect on Heart

Answer 144

Parasympathetic. Decrease heart rate and force of beat. Constricts coronary arteries

Question 145

Determinants of Blood Oxygen Content

Answer 145

1) PO2 2) amount of hemoglobin 3) hemoglobin binding affinity for oxygen

Question 146

NDF < 0

Answer 146

Net Driving Force < 3 Indicates reabsorption

Question 147

Jugular Venous Pulse Wave

Answer 147

There are no valves to impede flow between Right Internal Jugular Vein and the Right Atrium. Can learn about pressure in Right Atrium by examining vein's distention. from retrograde blood flow.

Question 148

Anulus Fibrosis

Answer 148

Ring of fibrous tissue surrounding right atrioventricular orifice. Serves as attachment site for cusps

Question 149

Hematocrit

Answer 149

Percentage of RBC in blood by volume

Question 150

Smooth and Cardiac Muscle T-Tubules

Answer 150

Smooth does not have them. Cardiac does.

Question 151

α1-adrenoreceptors

Answer 151

Sympathetic adrenergic nerves found on smooth muscles and heart. Stimulation via norepinephrine causes constriction

Question 152

Lingula

Answer 152

"tongue" of left superior lobe (lung), inferior to cardiac notch. Extends into Left Costomediastinal recess during inspiration

Question 153

Specific Vasodilator Peptide Hormones released by Mucosa of Intestinal Tract

Answer 153

1) Cholecystokinin 2) Vasoactive Intestinal Peptide 3) Gastrin 4) Secretin

Question 154

Transposition of the Great Arteries

Answer 154

Aorta from Right Ventricle and Pulmonary Artery from Left Ventricle. Failure of Aorticopulmonary Septum to spiral within Bulbus Cordis and Truncus Arteriosus. Abnormal migration of neural crest cells. Sometimes associated with a defect in the Membranous Part of Interventricular Septum. Usually accompanied by Patent Ductus Arteriosus (failure to close). Infant presents with Cyanosis. Condition fatal without surgery

Question 155

Firing Rate of AV Node / Bundle of His

Answer 155

50-60 bpm

Question 156

(ECG) Severe Hyperkalemia

Answer 156

Abnormality of Myocyte Repolarization. * Tall T-wave * Flattened P wave * Widened QRS

Question 157

Structures visible in Five Vessel Level (CT)

Answer 157

* Great Vessels: 1) R Brachicephalic Vein 2) L Brachicephalic Vein 3) Brachiocephalic Trunk 4) Common Carotid 5) Left Subclavian * Trachea (black due to air) * Esophagus (posterior to trachea; usually collapse may have some air)

Question 158

Passive Filling of Ventricles

Answer 158

Phases 6 and 7 are passive. Atrial Systole (phase 1) is active

Question 159

M2 Muscarinic Receptors in SA Node

Answer 159

1) Decrease rate of Phase 4 depolarization | 2) Increase efflux of K+

Question 160

Point of division of Brachiocephalic Trunk

Answer 160

Right sternoclavicular joint

Question 161

Metaarterioles

Answer 161

Intermediate vessel between arterioles and capillaries

Question 162

Regurgitation

Answer 162

Insufficiency. Backward flow of blood through a valve which fails to close properly

Question 163

Loss-of-Function Mutations in Atrial Fibrillation

Answer 163

Centered around Voltage-Gated K+ Channel, Kv1.5 Involved in atrial repolarization in phases 1-3. Leads to decrease in efflux of K+. Longer to reploarize. Leads to longer action potential and possibly early afterdepolarizations.

Question 164

Path for Bronchogenic Tumors to metastasize to Vertebral Column

Answer 164

Bronchial Veins -> Azygous Vein -> Posterior Intercostal Veins -> Intervertebral Veins -> Vertebral Venous Plexus

Question 165

Echocardiography

Answer 165

Ultrasound imaging technique used to, among other things, measure cardiac output

Question 166

Normal Duration of PR Interval

Answer 166

0.12 - 0.20 seconds 3-5 boxes

Question 167

Cardiac and Pulmonary Branches of Vagus Nerve

Answer 167

Leave Vagus Nerve in Superior Mediastinum. Course to Cardiac and Pulmonary Plexuses

Question 168

Blood Supply to Thymus

Answer 168

Branches of Internal Thoracic Artery and Inferior Thyroid Artery

Question 169

Branches of the fuse single aorta

Answer 169

1) Paired Intersegental Arteries 2) Unpaired Vitelline Arteries 3) Paired Umbilical Arteries 4) Paired Lateral Splanchnic Arteries

Question 170

Superior Mediastinum

Answer 170

Located above horizontal plane through sternal angle and T4-T5 intervertebral disc

Question 171

(ECG) Ventricular Fibrillation

Answer 171

* Disordered, rapid stimulation of ventricles * No coordinated contractions * Cessation of C.O. and death if not quickly reversed * Comes with severe heart disease (major cause of mortality in acute myocardial infarction) * Often initiated by an episode of VT which degenerates by breakup of waves into wavelets * NO QRS WAVES

Question 172

Origin of Brachiocephalic Trunk

Answer 172

from part of the Aortic Sac

Question 173

Transmural Pressure

Answer 173

Difference in pressure inside and outside a vessel

Question 174

Bipolar Limb Leads

Answer 174

Leads I, II, and III

Question 175

T Waves are Sensitive to...

Answer 175

1) Change in electrolytes 2) ischemia 3) las drogas

Question 176

Interventricular Foramen

Answer 176

Between the AV Septum and free edge of (growing) Muscular Ventricular Septum

Question 177

Intima

Answer 177

Innermost layer of vasculature. Single layer of thin endothelial cells. Separated from media (blood) by basal lamina

Question 178

Formation of Single Heart Tube

Answer 178

Paired (endocardial heart) tubes are brought together in lateral folding of the embryo and fuse. Form single heart tube at midline - the endocardium

Question 179

Location of valve for Foramen Ovale

Answer 179

Left Atrium

Question 180

Three articulations between ribs and vertebral column (Ribs 2-9)

Answer 180

1) Head-Vertebral Body 2) Head-Above vertebral Body 3) Posterior Curve - Transverse Process of Vertebrae

Question 181

Types of Ventricular Arrhythmias (Tachyarrhthmias)

Answer 181

1) Ventricular Premature Beats (VPB) 2) Ventricular Tachycardia 3) Ventricular Fibrillation

Question 182

Root of Lung

Answer 182

Collection of neurovascular structures that supply the lung. Covered by pleura.

Question 183

Change in pressure in pleural cavity during inspiration

Answer 183

decrease in pressure

Question 184

Cholinesterase activity in heart

Answer 184

High cholinesterase concentration in/around SA and AV nodes is the reason ACh effects from parasympathetics decay rapidly.

Question 185

Pleural Cavity

Answer 185

Potential space between parietal and visceral pleura under negative pressure. Contains a thin layer of serous fluid for lubrication

Question 186

Postganglionic Neuronal Bodies of Sympathetic Division (Location)

Answer 186

Sympathetic Chain or Preaortic Ganglia

Question 187

Floating Ribs

Answer 187

Not attached to sternum or adjacent ribs (Ribs 11-12)

Question 188

Esophageal Atresia with Tracheoesophageal Fistula

Answer 188

Due to improper fusion of Tracheoesophageal folds. Results in 'Polyhydramnios' - amniotic fluid drank by fetus cannot enter stomach Surgical intervention required.

Question 189

Hepatic Blood Flow sources

Answer 189

1) Portal Vein (75% by vol) | 2) Hepatic Artery (75% of O2 supply)

Question 190

Accessory Hemiazygous Vein

Answer 190

Drains middle left intercostal spaces. Crosses midline to drain into Azygous Vein

Question 191

Smallest Cardiac Veins (or Venae Cordis Minimae)

Answer 191

Tiny vessels within heart wall opening directly into chambers of the heart

Question 192

(ECG) Right Bundle Branch Block (RBBB)

Answer 192

* Normal depolarization of R Ventricle Interrupted * Initial depolarization of Ventricular Septum unaffected (stimulated by L Bundle) * Normal R wave in Lead VI and Small Q in V6 still recorded * Slow cell-to-cell depolarization in R Ventricle * Widened QRS complex * Late depolarization in R Ventricle produces R' wave in Lead V1 * Prominent Downward S wave in Lead V6 (not normally there)

Question 193

Aorticopulmonary Septum

Answer 193

Formed from fused Bulbar and Truncal Ridges. Divides Bulbus Cordis and Truncus Arteriosus into Ascending Aorta and Pulmonary Trunk. Half of each structure contributes to half of each great vessel.

Question 194

Fascicular Blocks

Answer 194

Also called Hemiblocks. Happen in Left Anterior/Posterior Fascicles of Left Ventricle. Do not result in widened QRS because Purkinje Fibers bridge the territories of each fascicle. Most useful to analyze limb leads.

Question 195

Posterior Descending Artery (or Posterior Interventricular Branch)

Answer 195

Located in the Posterior Interventricular Sulcus. Can anastomose with Anterior Interventricular Branch of Left Coronary Artery Supplies: 1) Right Ventricle 2) Left Ventricle 3) Posterior 1/3 of Interventricular Septum

Question 196

Factors shifting Hemoglobin-Oxygen Dissociation Curve to the Right

Answer 196

1) Increase in Temperature 2) Increase in PCO2 3) Decrease in pH

Question 197

Moderator Band or Septomarginal Trabecula

Answer 197

Single specialized trabeculum that forms bridge between lower portion of Interventricular Septum and Anterior wall at base of Anterior Papillary Muscle

Question 198

Cardiopulmonary Receptors Reflex

Answer 198

Type of stretch receptor called "low-pressure receptors". Located at Venoatrial Junctions of heart. Respond to atrial filling and contraction. Activated by increased central venous pressure/volume, leading to a decrease in sympathetic activity. Other types of cardiopulmonary receptors decreased ADH/Vasopression released from Posterior Pituitary. Decreased in blood volume and venous pressure

Question 199

Factors affecting venous return to heart

Answer 199

1) R Atrial Pressure 2) Mean Systemic Filling Pressure 3) Resistance to flow btwn peripheral vessels and R Atrium

Question 200

Meaning of P Wave

Answer 200

Atrial Depolarization

Question 201

Vertical Lines on Lateral View (Anterior to Posterior)

Answer 201

1) Anterior Axillary Line 2) Midaxillary Line 3) Posterior Axillary Line

Question 202

Umbilical Veins

Answer 202

1) Right umbilical vein degenerates | 2) Left Umbilical vein: Postnatally, fibrotic and form Ligamentum Teres Hepatis (round ligament of liver)

Question 203

Torsades de Pointes

Answer 203

Specific polymorphic VT with acute myocardial ischemia/infarction. Long QT syndrome.

Question 204

Prevertebral Ganglia

Answer 204

Also called Preaortic Anterior to lumbar vertebrae and abdominal aorta. Most of these associated with branches of abdominal aorta.

Question 205

Right and Left Vitelline Veins

Answer 205

Drain primitive gut. Form: 1) Hepatic Sinusoids 2) Ductus Venosus 3) Remainder of L Vitelline degenerates 4) Right Vitelline vein (enlarges to form pt of IVC and hepatic portal system)

Question 206

Atresia

Answer 206

Absence of normal lumen or opening (developmental)

Question 207

(ECG) Left Bundle Branch Block (LBBB)

Answer 207

* Normal initial depolarization of left septum does not occur * Right ventricular septum first to depolarize (move toward V6) * Initial downward deflection recorded in Lead V1 * Absent small Q wave from Lead V6 * Slow left ventricular spread results in Wide QRS * Abnormal second terminal upward deflection in leads over L Ventricle (V5, V6)

Question 208

Heart Rate and Systole/Diastole Time Relation

Answer 208

At rest, more time is spent in diastole than systole. Increasing heart rate shortens both but more so diastole.

Question 209

Rhythmic/Phasic Contraction (skeletal muscle perfusion)

Answer 209

Normal locomotory. Mean flow is higher. However, it's phasic so low flow during contraction (compressed vessels) and high at rest.

Question 210

Mutations involved with Dilated Cardiomyopathy

Answer 210

Majority of the mutations are genes encoding proteins in sarcomere 1) titin (most common) 2) cardiac troponins T, C, and I 3) desmin 4) myosin heavy chain

Question 211

Venous Return Formula

Answer 211

VR = (PSF - PRA) / RVP VR: Venous Return PRA: Right Atrial Pressure RVR: Resistance to Venous Return

Question 212

Role of Right Vagus on Heart

Answer 212

Primarily inhibits SA Node

Question 213

Paired Umbilical Arteries

Answer 213

Form... 1) Internal Iliac Arteries 2) superior vesical artery 3) distally, fibrous cord - medial umbilical ligament

Question 214

Fate of Caudal Part of Right Dorsal Aorta

Answer 214

degeneration

Question 215

Umbilical Vein

Answer 215

Feeds fresh blood from placenta to fetus (80-90% O2 saturation)

Question 216

Describe origin of Posterior Intercostal Arteries

Answer 216

Branch from the aorta. Exception: 1st/2nd branch from Superior Intercostal Artery

Question 217

Pectinate Muscles

Answer 217

form criss-crossing ridges of muscular anterior wall of right atrium

Question 218

Frank-Starling Law

Answer 218

Stretching of the sarcomere increases cardiac contractility

Question 219

All blood from gut, spleen, and pancreas immediately flows into Liver via...

Answer 219

Portal Vein

Question 220

Chorionic Villi

Answer 220

Capillary network where nutrients/waste exchanged between maternal and fetal blood without mixing. Blood returned to fetus via Umbilical veins

Question 221

Intervillous Space

Answer 221

Placental space which receives input and output of maternal blood for exchange with Chorionic Villi.

Question 222

Increased morbidity/mortality in LQTS

Answer 222

if QTc > 500 msec

Question 223

Gain-of-Function Mutations in Atrial Fibrillation

Answer 223

Channels: 1) Ks 2) Kr Mutations in all 5 regulatory subunits of Ks channels. Leads to increase in efflux of K+ and thus increase in rate of phases 2/3. Reduction in duration of both AP and effective refractory period in atrial myocytes

Question 224

Ways to Express Preload on Frank-Starling Curve

Answer 224

1) End Diastolic Volume 2) End Diastolic Pressure (most common clinically) 3) Right Atrial Pressure

Question 225

Hemiazygous Vein

Answer 225

Left side of anterior vertebral column. Continuation of Left Ascending Lumbar Vein as it passes posterior to diaphragm. Drains Left Posterolateral Abdominal wall directly into Inferior Vena Cava before becoming Hemiazygous Vein. Enters thorax through Diaphragmatic Crura. Drains lower left intercostal spaces via Left Posterior Intercostal Veins. Crosses midline to drain into Azygous Vein

Question 226

Fate of Septum Primum

Answer 226

Upper part degenerates. Lower part becomes the valve of Foramen Ovale

Question 227

J Point (ECG)

Answer 227

Point at which ST Segment begins (end of S Wave)

Question 228

Structures visible in Aortic Arch Level (CT)

Answer 228

* Aortic Arch * Superior Vena Cava * Arch of Azygous (emptying into the SVC)

Question 229

Pulmonary Valve

Answer 229

Located at pulmonary orifice at superior end of Conus Arteriosus. Have three semilunar cusps. Cusps catch backflow from pulmonary trunk after systole and close off orifice

Question 230

Rhythmicity

Answer 230

Regularity of pacemaking activity

Question 231

Pleurisy

Answer 231

Inflammation of pleura. Can result in fibrous connective tissue adhesions between visceral and parietal pleura.

Question 232

Antipyretics

Answer 232

Drugs that reduce fever

Question 233

Right Coronary Artery

Answer 233

Arises from opening to right aortic sinus. Descends in Atrioventricular Sulcus Supplies: 1) Right Atrium 2) Right Ventricle 3) Sinoatrial Node 4) Atrioventricular Node 5) Interatrial Septum 6) Posterior 1/3 of Interventricular Septum

Question 234

Nucleus Tractus Solitaris

Answer 234

Area in medulla receiving sensory fibers from CN IX and X. Includes information from baroreceptors and chemoreceptors

Question 235

(ECG) Third Degree AV Conduction System Block

Answer 235

* "complete heart block" (conduction failure) * No relationship between P wave and QRS * SA node depolarizes atria; ventricles rely on escape rhythm * If escape from AV node - QRS normal (40-60 bpm) * If escape from His-Purkinje - QRS widened and slower

Question 236

(ECG "hints") T Waves

Answer 236

Each T wave begins with a gradual rise, falling more abruptly distally. Sharp proximal rise in ST segment is SUSPICIOUS

Question 237

Normal Cardiac Rhythm / Sinus Rhythm

Answer 237

Every P wave followed by QRS. Every QRS preceded by P wave. Leads I, II, and III have UPRIGHT P

Question 238

Compartments of the Thoracic Cavity

Answer 238

1) Right Pulmonary Cavity 2) Left Pulmonary Cavity 3) Central Mediastinum

Question 239

Implication of shorter diastole during Tachycardia

Answer 239

Less time for venous return, decreases cardiac output. Most myocardium blood perfusion is during diastole so less effective perfusion via Coronary Arteries.

Question 240

Beginning of Heart Development

Answer 240

Begins on Day 18 in Cardigenic Area of Splanchnic Mesoderm

Question 241

Resistance/Flow and Stenosed Arteries

Answer 241

* Increased velocity in narrowed segment * Some fluid energy is lost to KE. Less energy to pressure * Decrease in pressure exacerbates tendency to close shut

Question 242

Released from Gastrointestinal Glands during Active Absorption of Nutrients. Vasodilator

Answer 242

Bradykinin

Question 243

Terminal Ganglia

Answer 243

Parasympathetic ganglia located adjacent to or within the walls of organs

Question 244

Oxygen Lack Theory

Answer 244

Local regulatory theory Oxygen is needed for vascular muscle contraction. If there's an absence, smooth muscle relaxes (vessel dilates). So decreased oxygen leads to increase in blood flow

Question 245

Renin released by kidneys in response to...

Answer 245

1) Sympathetic stimulation 2) hypotension 3) decreased sodium in distal tubules

Question 246

Key CT Scan Levels (windowing view) (Superior to Inferior)

Answer 246

1) Five-Vessel Level 2) Aortic Arch Level 3) Aortopulmonary Window Level 4) Main Pulmonary Artery Level 5) High Cardiac Level 6) Low Cardiac Level

Question 247

Net Systemic Effects of Angiotensin II

Answer 247

Increase: 1) Blood volume 2) venous pressure 3) arterial pressure

Question 248

Structures in Aortic Hiatus

Answer 248

1) Descending Aorta 2) Thoracic Duct 3) Azygous Vein

Question 249

Least Splanchnic Nerves

Answer 249

Arise from 12th Thoracic Ganglion. End in Renal Plexus

Question 250

Histamine

Answer 250

Released in response to tissue damage, inflammation, or allergic reaction. Mostly derived from mast cells in damaged tissue or basophils in blood. It's a vasodilator (arterioles) and increases capillary permeability

Question 251

(ECG) Atrial Fibrillation

Answer 251

* Chaotic rhythm with very fast atrial rate (350-600 bpm) * Multiple Wandering Reentrant Circuits in Atria * No P waves or fine, high frequency, low voltage "noise" * QRS-T normal but irregular timing * many impulses encounter refractory AV node * untreated AF has 140-160 bpm rate

Question 252

(ECG) Acute ST Segment Elevation Myocardial Infarction (Acute STEMI)

Answer 252

Temporal sequence of ST Segment and T wave abnormalities. (gonna have to look at this one) 1) Acute: ST elevation 2) Hours: ST elevated, lowered R wave, appearance of Q wave 3) Day 1-2: T wave inverts, deeper Q 4) Days: ST normalizes, T still inverted 5) Weeks: ST + T normalized. Q wave persists

Question 253

What are pain fibers in the heart sensitive to?

Answer 253

Metabolic products from ischemia in myocardium

Question 254

Tricuspid Valve

Answer 254

Prevent blood flow back to right atrium following ventricular contraction. Three Cusps: 1) Anterior Cusp (anterior wall of ventricle) 2) Posterior Cusp (inferior to anterior cusp) 3) Septal Cusp (posterior on Interventricular septal wall)

Question 255

Discontinuous Capillaries

Answer 255

Large intercellular gaps. Gaps in basement membrane. Found in: Liber, spleen, and bone marrow

Question 256

Things which can force constriction of esophagus

Answer 256

Esophagus forced to constrict when filled/constricted 1) Pharynx narrowing 2) Arch of Aorta 3) Left Main Bronchus 4) Diaphragm

Question 257

Effect of Phosphorylating Light Chains of Myosin (MLC)

Answer 257

Increase Myosin ATPase Activity

Question 258

Three methods of removing Ca2+ during smooth muscle relaxation

Answer 258

1) SR Ca2+-ATPase (SERCA) 2) Plasma Membrane Ca2+ Pump 3) Na+-Ca2+ Exchanger (plasma membrane)

Question 259

Only way to rid body heat if Ambient Temp> Skin Temp

Answer 259

Evaporation (sweating)

Question 260

Origin of Internal Thoracic Artery

Answer 260

Subclavian Artery

Question 261

Function of Intercostal Muscles

Answer 261

support thoracic wall and change volume during breathing

Question 262

Checking for Effusion on X-ray

Answer 262

Costophrenic angles should be sharp. A blunted angle may indicate small effusion

Question 263

Thoracic Splanchnic Nerves

Answer 263

Originate from Lower 7 Ganglia in Sympathetic Trunks. Mainly preganglionic sympathetic fibers, also containing visceral afferent fibers. Form three nerves: 1) Greater Splanchnic Nerves 2) Lesser Splanchnic Nerves 3) Least Splanchnic Nerves

Question 264

Cardiac Index

Answer 264

Cardiac output per m^2 body surface (usually 2.6-4.2 L/min/m^2)

Question 265

Oxygenated Blood Supply to Non-Respiratory Tissue of Lungs

Answer 265

Branchial Arteries. Supply root, supporting lung tissue and visceral pleura. Right Lung: 1 branched from either Aorta of 3rd posterior intercostal artery Left Lung: 2 branched directly from Aorta

Question 266

0 < σ < 1

Answer 266

Capillary partially permeable

Question 267

Fate of Right and Left Anterior Cardinal Veins

Answer 267

* Both contribute to Internal Jugular Vein. Become connected by "Oblique Anastomosis" which becomes left brachiocephalic vein * Right Anterior Cardinal Vein contributes to Right Brachioephalic * Terminal part of Right Anterior Cardinal V and Right Common Cardinal form Superior Vena Canva * Posterior Cardinal veins degenerate

Question 268

(ECG) Second Degree AV Conduction System Block, Mobitz Type I

Answer 268

* Progressive increase in PR interval from one beat to next * Eventually, you miss a QRS complex * After, PR interval resets to initial length and cycle repeats usually benign

Question 269

Vertical Lines on Anterior View

Answer 269

1) Anterior Median (Mediasternal) Line | 2) Midclavicular Line

Question 270

Left Coronary Artery Divides into..

Answer 270

1) Left Anterior Descending (LAD) or Anterior Interventricular Branch 2) Circumflex Branch (artery)

Question 271

Thermoreceptors of the Skin

Answer 271

Cold receptors most abundant. Also warm ones. Reflex effects when chilled: 1) Shivering / increasing heat 2) Inhibition of sweating 3) Vasoconstriction

Question 272

Fate of Distal Part of Aortic Arch 6

Answer 272

Degenerates on the right but on the left it persists as the Ductus Arteriosus

Question 273

(Cardiac Cycle) Phase 4: Reduced Ejection

Answer 273

Ventricular repolarization. Atrial volume and pressure continue to rise (venous return). Tension in ventricular muscle begins to decrease, along with intraventricular pressure and the ejection rate of blood. 30% of blood ejected in this phase. Aortic pressure begins to decrease because resistance to flow of peripheral vessels begins to overtake ventricular output. Slowed output through semilunar valves means reverse flow begins. Valves close, marking the beginning of diastole.

Question 274

Reynold's Number (Re)

Answer 274

Used to predict turbulence under ideal conditions see formula sheet for actual formula

Question 275

Active Hyperemia

Answer 275

Increased in blood flow associated with metabolic activity of tissue/organ

Question 276

Anterior and Posterior Sulcus (Heart)

Answer 276

Separate right/left ventricles

Question 277

(ECG) Ventricular Premature Beats (VPB)

Answer 277

* Arises when ectopic ventricular focus fires AP * Widened QRS complex (depolarization via slow cell-to-cell transmission) * unrelated preceding P wave * T wave in opposite direction of QRS Repeating Patterns: 1) Every beat 2) Bigeminy - every alternate 3) Trigeminy - two normal, one VPB 4) Couplets - two in a row 5) triplets - three in a row

Question 278

Roughened parts of Right Atrium

Answer 278

Right Auricle and Anterior Wall

Question 279

Enhanced Automaticity of Latent Pacemakers

Answer 279

Mechanism of Tachycardia. Latent pacemarker's rate > SA node rate. Ectopic beat / Ectopic rhythm -- premature to normal rhythm Several Circumstances: 1) High catecholamine concentration can enhance automaticity 2) Hypoxemia, Ischemia, Electrolyte Disturbances, and drug toxicities

Question 280

Mechanical Efficiency of the Heart

Answer 280

Also called Cardiac Efficiency. Typically around 25% = PVA/MVO2 = work/total energy use

Question 281

Long QT Syndrome (LQTS)

Answer 281

Longer cardiac repolarization and refractory period. Genetic defects in cardiac voltage-activated sodium and potassium channels. Loss of function mutations Male QT interval (.35-.45 s), Female QT (.36-.46 s) Physical and emotional stress triggers syncope or sudden death.

Question 282

Fibrous Pericardium, Embyrological Origin

Answer 282

Body Wall (Somatic) Mesoderm of lateral plate

Question 283

Costal Margin

Answer 283

Formed by costal cartilages of Ribs 7-10 rising up to the sternum

Question 284

Sources of Thoracic Duct Drainage

Answer 284

1) All lymph below diaphragm 2) L Side Thoracic Cavity 3) L Side Head/Neck 4) L Upper Extremity

Question 285

Dilations of the Heart Tube (Rostral/Arterial to Caudal/Venous)

Answer 285

Occurs by Day 23. 1) Truncus Arteriosus 2) Bulbus Cordis 3) Primitive Ventricle 4) Primitive Atrium 5) Sinus Venosus

Question 286

(ECG "hints") Leads V1-V6

Answer 286

Amplitude of R wave normally increases until it reaches a Equiphasic RS complex at V3. Continues to rise through V6

Question 287

Superior Aspect of the Manubrium

Answer 287

Jugular (or Suprasternal) Notch

Question 288

Murmurs

Answer 288

Heart sounds generated by turbulent bloodflow

Question 289

Endothelin-1 (ET-1)

Answer 289

Vasoconstrictor From intracellular precursor, Big Endothelin-1. Synthesized by Endothelin-Converting Eznyme (ECE) on Endothelial membrane

Question 290

Two factors determining blood flow (generally)

Answer 290

1) Pressure Difference (Perfusion Pressure) | 2) Resistance

Question 291

Umbilical Arteries

Answer 291

Fetus to placenta flow. 3/5 of Descending Aorta blood in fetus directed to placenta this way.

Question 292

Parts combining to form Definitive Left Atrium

Answer 292

1) Primitive Left Atrium which forms Definitive Left Auricle | 2) Pulmonary Vein and its smooth-walled lumen incorporated as smooth-walled part

Question 293

Tumor of Liver / Right Atrium Collaterals

Answer 293

Tumor of liver can destruct Inverior Vena Cava. Collateral pathway through SVC Lumbar veins-> R/L Ascending Lumbar Vein -> Hemiazygous Vein - Azygous Vein -> SVC

Question 294

Foramen Primum Defect

Answer 294

Partial fusion of endocardial cushions, leads to a gap in the inferior part of the Atrial Septum. Ventricular septum intact. Endocardial cushions fuse enough to form membranous part of IV Septum, just not enough to join septum primum

Question 295

Terminal Branches of Internal Thoracic Artery

Answer 295

Musculophrenic and Superior Epigastric Arteries

Question 296

Function of Aldosterone

Answer 296

Increase renal Na reabsorption

Question 297

Body Heat / Epinephrine+NE

Answer 297

Affect rate of metabolism with 40-50% increase. Boost body heat

Question 298

Ventricular Escape

Answer 298

Escape Rhythm from distal points of the conduction system. Very strong parasympathetic activity can surpass the SA and AV nodes. Purkinje fibers doing the pacemaking

Question 299

Left Atrium and Esophagus

Answer 299

Hypertrophy of the Left Atrium can cause compression and displacement of posteriorly-located esophagus

Question 300

Unpaired Branches to Viscera from Descending Aorta

Answer 300

1) Left Bronchial Arteries (2) 2) Esophageal Arteries (2-5) 3) Mediastinal Arteries 4) Pericardial Arteries

Question 301

Collateralization

Answer 301

In heart/coronary artery network, increased number of parallel vessels can reduce resistance

Question 302

What are actin filaments in Smooth Muscle missing

Answer 302

no troponin

Question 303

Triggered Activity

Answer 303

Mechanism of Tachycardia. Action potentials under certain conditions can trigger extra heart beats or rapid arrhythmias. 1) Early Afterdepolarizations 2) Delayed Afterdepolarizations

Question 304

Compliance

Answer 304

"Distensibility" Ability of hollow organ to distend and increase in volume in response to increased pressure

Question 305

Patent Ductus Arteriosus (PDA)

Answer 305

Failure to close results in persistent Descending Aorta - Pulmonary Artery shunt. Blood flows. Volume overloading of Pulmonary Circulation, L Atrium, and L Ventricle. Left Ventricular Dilation and Left-Sided Heart Failure

Question 306

Primary Capacitance Vessels of the Body

Answer 306

Venules and Veins

Question 307

Pleural Friction Rub

Answer 307

Sound during breathing with Pleurisy (inflammation of pleura).

Question 308

Posterior Myocardial Infarction (Leads and Typical Artery)

Answer 308

Leads V1-V2 (remember this is the weird, odd-ball case) Right Coronary Artery

Question 309

Order of Functional Potency of Adrenergic Receptors (Heart)

Answer 309

Beta-1, Beta-2, Alpha-1

Question 310

Types of External Intermittent Compression on Lymphatic Vessels

Answer 310

1) Contraction of skeletal muscle 2) movement of body 3) Pulsation of adjacent arteries 4) Compression of tissues by objects outside body

Question 311

Coursing of Left Posterior Fascicle

Answer 311

Runs through Posterior, Inferior, and Medial Left Ventricle

Question 312

Branches of Left Bundle Branch

Answer 312

1) Left Anterior Fascicle | 2) Left Posterior Fascicle

Question 313

Septum Transversum

Answer 313

Future central tendon of the diaphragm. Veins must pass through it first to reach Sinus Venosus

Question 314

Arch of the Azygous Vein

Answer 314

Arches superior to root of right lung before draining into SVC

Question 315

Innermost Intercostal Muscles

Answer 315

Oriented in same direction and act with Internal Intercostal Muscles. Found in lateral most portion of Thoracic Wall

Question 316

Released from Adrenal Medulla

Answer 316

Epinephrine and Norepinephrine

Question 317

Innervation of Intercostal Muscles

Answer 317

Intercostal Nerves (from Ventral Rami of Thoracic Spinal Nerves)

Question 318

Functions of Angiotensin II (7)

Answer 318

1) Aldosterone Release 2) Direct stimulation of Renal Na reabsorption 3) Stimulate thirst 4) Stimulate released of ADH 5) Systemic Vasoconstriction 6) Activate Sympathetics 7) Cardiac/Vascular Smooth Muscle Hypertrophy

Question 319

Origin of Superior Intercostal Artery

Answer 319

Costocervical trunk of subclavian artery

Question 320

Paired dorsal aortae (caudal to heart) fuse to form...

Answer 320

single aorta

Question 321

Muscular Ventricular Septum

Answer 321

Forms in midling of floor of ventricle; grows toward AV Septum

Question 322

Landmark for start of Descending/Thoracic Aorta

Answer 322

Continuation of Aortic Arch inferior to level of sternal angle

Question 323

Paired Parietal Branches of the Descending Aorta

Answer 323

1) Posterior Intercostal Arteries (9 pair - Intercostal spaces 3-11) 2) Subcostal Artery (1 pair) - supplies below rib 12

Question 324

Overall Vascular Compliance dependent on...

Answer 324

Venous compliance (15x more blood)

Question 325

Aortic Arches in Development

Answer 325

* Originate from rostral end of Truncus Arteriosus. * Supply Pharyngeal Arches * Connected to Paired Dorsal Aortae

Question 326

Subregions of Pericardial Cavity

Answer 326

1) Transverse Pericardial Sinus | 2) Oblique Pericardial Sinus

Question 327

Exceptions to Sympathetic/Parasympathic Dual Innervation to Same Organ

Answer 327

1) Sweat Glands 2) Adrenal Medulla 3) Arrector Pili Muscles

Question 328

Causes of Edema

Answer 328

1) Increased Capillary Pressure 2) Increased capillary permeability 3) Decreased plasma oncotic pressure 4) Lymphatic blockage (Lymphedema)

Question 329

Corrected QT Interval

Answer 329

Allows for comparison of QT interval, corrected for different heart rates. = QT / sqrt(RR) Normal value <= 0.44 seconds

Question 330

Conduction Blocks

Answer 330

Bradycardic. Impulse encounters unexcitable region. Can be transient/permanent, unidirectional or bidirectional. Caused by: 1) Ischemia 2) Fibrosis 3) Inflammation 4) drugs 5) etc..

Question 331

(ECG "hints") Lead V1

Answer 331

* Small initial R wave (sometimes not able to see) * Deep(er) S Wave * T wave maybe positive, biphasic, or negative

Question 332

Membranous Ventricular Septum

Answer 332

Closed Interventricular Foramen. Formed by fusion of three structures: 1) Right Bulbar Ridge 2) Left Bulbar Ridge 3) Atrioventricular Septum

Question 333

Right Axis Deviation

Answer 333

Mean Electrical Axis of greater than +90

Question 334

Preload

Answer 334

Stretch of Ventricular muscle fibers before contraction. End Diastolic Volume and End Diastolic Pressure are good measures of Preload.

Question 335

PR Interval

Answer 335

Atrial Depolarization and AV Delay. P wave to start of QRS.

Question 336

(Cardiac Cycle) Phase 5: Isovolumetric Relaxation

Answer 336

Ventricles continue to relax. Decline in pressure. Decline in Aortic Pressure is not abrupt (smaller arteries resist flow but elastic recoil of vessels maintains pressure). End Systolic Volume

Question 337

Peripheral Venous Pool

Answer 337

Blood contained within veins of systemic organs

Question 338

(ECG) Atrial Fluter

Answer 338

* Rapid, regular atrial activity at a rate of 180-350 bpm * Usually caused by Large Anatomically-Fixed Circuit * Impulses reach AV node during refraction (often do not conduct; 2+ beats of atria per ventricle beat) * Asymptomatic under 100 bpm * > 100 bpm: palpitations, dyspnea, or weakness

Question 339

(ECG "hints") Lead aVR

Answer 339

All complexes (P-QRS-T) normally negative

Question 340

Central Venous Pool

Answer 340

Smaller reservoir of blood in Great Veins of Thorax and Right Atrium

Question 341

(ECG) Hypercalcemia

Answer 341

Abnormality of Myocyte Repolarization. * Shortened QT interval

Question 342

Drainage of Branchial Veins

Answer 342

Right: Azygous Vein Left: Accessory Hemiazygous or Left Superior Intercostal Vein

Question 343

Right and Left Brachiocephalic Veins

Answer 343

Union of Internal Jugular and Subclavian Veins. Begins posterior to Sternoclavicular Joints.

Question 344

Parts of the Sternum

Answer 344

1) Manubrium 2) Body 3) Xiphoid Process

Question 345

(Fast Response Action Potential Receptors) Phase 3

Answer 345

Repolarization by Potassium efflux through delayed rectifier channels. Slow activating current first, followed by fast activating current.

Question 346

Posterior Mediastinum

Answer 346

Between pericardium and lower 8 thoracic vertebrae. Contains tubular structures (esophagus, aorta, etc...)

Question 347

Dicrotic Notch

Answer 347

Closure of Aortic Valve during Phase 4 of Cardiac Cycle (Reduced Ejection) momentarily interrupts the decline in Aortic pressure

Question 348

Deviation in Left Posterior Fascicle Block

Answer 348

Right Axis Deviation

Question 349

Higher Bloodflow Velocity? Semilunar or AV Valves?

Answer 349

Semilunar Valves have smaller openings, therefore faster velocity.

Question 350

Bruit

Answer 350

Sound generated by turbulent blood flow in vessel

Question 351

Contents of Lung Hilum

Answer 351

1) Bronchi (posterior) 2) Pulmonary Artery (Anterior/Superior) 3) Pulmonary Vein (Anterior/Inferior) 4) Bronchial Arteries/Veins

Question 352

Superior Vena Cava

Answer 352

Union of Right and Left Brachiocephalic Veins. Extends from Costal Cartilage levels 1-3. Recieves Azygous Vein @ level of Sternal Angle before entering the Right Atrium Deoxygenated blood from all structures above the diaphragm

Question 353

(ECG "hints") Lead II

Answer 353

All complexes (P-QRS-T) normally positive

Question 354

Escape Rhythm

Answer 354

Surpressed SA Node allows a latent pacemaker to fire an impulse (escape beat). A continued series is called an Escape Rhythm

Question 355

Central Venous Pressure

Answer 355

Blood pressure in Thoracic Vena Cava near R Atrium. good approximation of right atrial pressure.

Question 356

Fixed Conduction Block

Answer 356

Area unexcitable because of barrier imposed by fibrosis or scarring that replaces myocytes

Question 357

Anterior (Sternocostal) Surface of Heart

Answer 357

Mostly right ventricle, some right atrium

Question 358

Bypassed in fetal circulation

Answer 358

Liver and Lungs

Question 359

Make-up of Capillaries

Answer 359

Composed of just endothelial cells and a basal lamina

Question 360

Mechanisms of Exchange Through Capillary Endothelia

Answer 360

1) Diffusion 2) Bulk Flow 3) Vesicular Transport 4) Active Transport

Question 361

Tissue (Interstitial) Hydrostatic Pressure

Answer 361

ΔPi = ΔVi / C ΔPi : Δ interstitial fluid pressure ΔVi: Δ interstitial fluid volume C: Interstitial Compliance

Question 362

Trachea

Answer 362

Begins in neck below Larynx (C6). Contains cartilagenous rings. Anterior and to the right of Esophagus. Divides into Principal Bronchi at level of sternal angle. Principal bronchi within the Middle Mediastinum

Question 363

Vertebral Level: Aortic Hiatus

Answer 363

T12

Question 364

Flow Capacity (Vasodilator Reserve)

Answer 364

Difference between basal and maximal flow to organs

Question 365

Muscular Part of Interventricular Septum

Answer 365

Thick, forms most of septum

Question 366

Opening of Pulmonary Circulation Afterbirth

Answer 366

Lungs expand and open up. Increased PO2 from breathing leads to pulmonary vasodilation

Question 367

Net Driving Force Equation

Answer 367

NDF = (Pc-Pi) - σ(πc-πi)

Question 368

Division of Primitive Atrium

Answer 368

Accomplished by fusion of Septum Primum and Septum Secundum. These also fuse to Endocardial Cushions

Question 369

(Cardiac Cycle) Phase 2: Isovolumetric Contraction

Answer 369

Spread of action potential through ventricles. Rapid increase in intraventricular pressure. Closure of Atrioventricular (Tricuspid/Mitral) Valves. Volume is constant since AV and Semilunar valves are closed

Question 370

Clinical concern with Costodiaphragmatic Recess

Answer 370

Fluids can accumulate (blood, lymph) in disease states (visualized on x-ray)

Question 371

Naming of Intercostal Spaces

Answer 371

Named for rib ABOVE

Question 372

Structures Visible in Low Cardiac Level

Answer 372

1) L/R Atria 2) L/R Ventricles 3) Interventricular Septum 4) Descending Aorta 5) Pericardium

Question 373

Function of Vasopressin/ADH

Answer 373

Primary function is to increase water retention. Leads to increase in blood volume and arterial pressure. Secondary function - direct vasoconstrictor actions at high levels

Question 374

(ECG) Sinus Tachycardia

Answer 374

* Elevated SA node discharge rate > 100 bpm * Normal P Waves and QRS * Occurs most often from increased sympathetics or decreased vagal tone * Appropriate response to exercise Pathological Causes (all sympathetic): 1) fever 2) hypoxemia 3) hyperthyroidism 4) hypovolemia 5) anemia

Question 375

Total Energy (Heart)

Answer 375

Energy = External Work + Elastic Potential Energy

Question 376

True Ribs

Answer 376

Directly attach to sternum. Ribs 1-7

Question 377

Effect of Temperature on SA Node

Answer 377

Increasing temperature increasing discharge frequency. May contribute to Tachycardia from fever.

Question 378

Sympathetics effect on Lungs

Answer 378

1) dilate respiratory passageways (Bronchodilation) 2) vasoconstriction 3) decrease mucous secretion

Question 379

Visceral Pleura

Answer 379

Covers lungs

Question 380

Vasodilatory Substances

Answer 380

Adenosine, CO2, K+, H+

Question 381

Issue with Left Dominant Heart

Answer 381

Entire Interventricular Septum supplied by Left Coronary Artery. Occlusive blockage will result in ischemia. Decreased survival from blockage

Question 382

Venous Drainage of Posterior Intercostal Veins

Answer 382

* Right Side: Azygous Vein | * Left Side: Accessory Hemiazygous and Hemiazygous Veins

Question 383

Costomediastinal Recess

Answer 383

Formed by costal and mediastinal pleura. Anterior margins of lung pass into this space during inspiration. Prominent on the left side.

Question 384

LQT1

Answer 384

Type of Long QT Syndrome. Mutations lead to defective Ks channel (current reduced). Symptoms triggered by emotional or physical stress. Exercise more likely to trigger cardiac event than in either LQT2 or LQT3

Question 385

Name for area connecting rib and costal cartilage

Answer 385

Costochondral Junction

Question 386

Vertebral Levels from which Splanchnic Nerves Emanate

Answer 386

T5-L2

Question 387

Driving Force for Venous Return

Answer 387

Difference between Right Atrial Pressure and Mean Systemic Filling Pressure (PSF)

Question 388

Location of Deep Body (Thermal) Receptors

Answer 388

1) Spinal Cord 2) Abdominal Viscera 3) In/Around Great Veins of Upper Abdomen/Thorax

Question 389

Insertion of Transversus Thoracis

Answer 389

Lower border of costal cartilages of Ribs 3-6. Fibers cross 1-2 intercostal space

Question 390

M2 Muscarinic Receptors in Heart

Answer 390

Bind ACh. Dramatic negative chronotropic and dromotopic effects. Modest inotropic effect primarily on the atria.

Question 391

Conditions causing hypereffective heart

Answer 391

1) Sympathetic Stimulation | 2) Trained Athletes (increased cardiac mass / contractile strength)

Question 392

Cardiac Output

Answer 392

Volume of blood ejected by ventricle per minute CO = SV * HR

Question 393

Parts of Interventricular Spetum

Answer 393

1) Muscular Part | 2) Membranous Part

Question 394

Closure of Foramen Ovale Afterbirth

Answer 394

Left atrial pressure becomes higher than right. 1) Functional closure in 18-24 hrs via smooth muscle, drop in circulating PGE2, and pressure of lumen in ductus 2) anatomical occlusion over the next few days via endothelial and fibrous tissue proliferation

Question 395

Preload

Answer 395

Stretch of cardiac muscle before contraction. Cardiac muscle normally at less than max preload, allowing it to meet increased demand.

Question 396

Endothelial-Derived Factors

Answer 396

Vascular endothelium has important paracrine role in regulating smooth muscle tone and blood flow. Release Stimulated by: a) Endocrine / Paracrine Hormones b) Shearing Forces c) Hypoxia d) Drugs _____ Factors: 1) Nitric Oxide 2) Endothelial-Derived Hyperpolarizing Factor (EDHF) 3) Endothelin-1 (ET-1) 4) Prostacyclin (PGI2) 5) Thromboxane 6) Leukotrienes

Question 397

Somatomotor Central Command Center

Answer 397

Area in cerebral cortex which recruits muscles needed for specific activity. Functions as a "Feed-Forward" center sending signals to regulatory areas of meddula to activate respiratory/cardiovacular regulators

Question 398

Meaning of U Wave (if present in EKG)

Answer 398

Follows T Wave; terminal stages of ventricular repolarization, possibly Purkinje Network

Question 399

Path out of liver for blood

Answer 399

Leaves via Hepatic Veins then goes to Inferior Vena Cava

Question 400

Atrivoentricular Block

Answer 400

Blocked/Unexcitable Atrioventricular connections removes normal Overdrive Suppression keeping His-Purkinje system in check. Emergences of escape beats/rhythms

Question 401

Hilum of Lung

Answer 401

Area where nerves and vessels enter and leave lung.

Question 402

Middle Mediastinum

Answer 402

Contains heart, pericardium surrounding heart

Question 403

Bulbar and Truncal Ridges

Answer 403

Ridges formed by Neural Crest Cells that grow longitudinally and spiral down Bulbus Cordis and Truncus Arteriosus. Fuse to form Aorticopulomary Septum

Question 404

SR Ca2+-ATPase (SERCA)

Answer 404

pumps Ca2+ back into SR during muscle relaxation

Question 405

Structures Visible in High Cardiac Level

Answer 405

1) L/R Atria 2) L/R VentricleS 3) Ascending/Descending Aorta

Question 406

Adventitia

Answer 406

Outermost layer of vasculature. Contains... 1) Collagen 2) fibroblasts 3) blood vessels (Vasa Vasorum) 4) Autonomic nerves (mainly sympathetic)

Question 407

Atrioventricular Reentrant Tachycardias (AVRT)

Answer 407

Presence of abnormal, Accessory Pathway, ideal condition for reentry. Refractory period different. Conduction usually faster through accessory pathway than AV Node.

Question 408

(Cardiac Cycle) Phase 3: Rapid Ejection

Answer 408

Aortic and Pulmonary Valves open when left/right ventricular pressure exceeds that of the exiting vessel. Ventricle muscle shortens, leading to decrease in ventricular volume. Period of peak flow from ventricles to Aorta/Pulmonary Artery. Atrial volume increasing because the AV valves are closed and venous return ongoing. 70% of stroke volume ejected in this phase

Question 409

Fetal Hemoglobin

Answer 409

Higher oxygen affinity than adult hemoglobin

Question 410

Count-Off Method (Calculating Heart Rate)

Answer 410

Memorize: Start-300-__-100-75-60-50 (each 1 box) Count # of large boxes between 2 beats. estimation of heart rate

Question 411

Normal Duration of QRS Complex

Answer 411

0.06-0.10 seconds ~1-2.5 boxes

Question 412

Effect of Thyroid Hormone on Cardiovascular System

Answer 412

Excess thyroid hormone leads to increase in Heart Rate, Stroke Volume, Contractility, and Cardiac Output.

Question 413

(Jugular Venous Pulse Graph) Y Descent

Answer 413

Rapid flow of blood into the right ventricle. Opening of the Tricuspid Valve at end of Isovolumetric relaxation phase

Question 414

Anterior Cardiac Veins

Answer 414

2-4 draining directly into the Right Atrium

Question 415

Pressure Volume Area (PVA)

Answer 415

Represents total mechanical energy generated by single beat of the heart. PVA = SW + PE

Question 416

Determinants of Resistance in a Vessel

Answer 416

1) Vessel Length 2) Blood Viscosity 3) Radius

Question 417

Structures in Caval Opening

Answer 417

1) Inferior Vena Cava | 2) Right Phrenic Nerve

Question 418

Nitric Oxide (dilate/constrict?)

Answer 418

Vasodilator

Question 419

Fick Principle

Answer 419

Xtc = Q[X]a - Q [X]v = Q([X]a - [X]v) ``` Xtc = Substance consumed by organ Q[X]a = Substance entering during given time Q[X]v = Substance exiting during given time Q = flow rate ```

Question 420

External Intercostal Membrane

Answer 420

Thin aponeurosis replacing external intercostal muscles in ANTERIOR part of each intercostal space

Question 421

Most likely to be damaged if upper intercostal space perforated/puncture

Answer 421

Intercostal Nerve

Question 422

(ECG) Digoxin Therapy

Answer 422

Abnormality of Myocyte Repolarization. * "Scooped" ST depression * Mildly lengthened PR Interval

Question 423

Paired Intersegmental Arteries

Answer 423

Form definitive... * Posterior Intercostal and Lumbar Arteries * Arteries to upper extremity (part/all of R/L subclavian arteries) * Arteries to Lower Extremity (Common Iliac Arteries)

Question 424

Causes of Right Axis Deviation

Answer 424

1) Right Ventricular Hypertrophy 2) Acute Right Heart Strain (e.g. massive pulmonary embolism) 3) Left Posterior Fascicular Block

Question 425

Forms epicardium of heart

Answer 425

Visceral Layer of Serous Pericardium

Question 426

Atrioventricular Sulcus

Answer 426

Separates the atria from ventricles. Also called Coronary sulcus

Question 427

Alpha-2 Adrenergic Receptors

Answer 427

Norepinephrine receptors on sympathetic nerves which acts as a negative feedback loop. Inhibits further release of Norepinephrine

Question 428

Effects of Increase Intracranial Pressure (cerebral perfusion)

Answer 428

1) Collapsed Veins | 2) Reduced effective blood flow

Question 429

Vagal Trunks

Answer 429

Pass through Diaphragm with Esophagus. Left Vagal Trunk = Anterior Esophagus Right Vagal Trunk = Posterior Esophagus

Question 430

Fourth Heart Sound (S4)

Answer 430

Coincides with Atrial Contraction during late ventricular diastole. Commonly associated with resistance to filling (impaired relaxation) Sign of diastolic heart failure

Question 431

Fistula

Answer 431

Abnormal channel between two structures

Question 432

Neural center for sweating

Answer 432

Anterior Hypothalamus (Preoptic Area). Sweat glands are sympathetically innervated by cholinergic fibers

Question 433

Easy way to tell if Mean QRS Axis is normal

Answer 433

Lead I/II predominantly upright

Question 434

Carina

Answer 434

Internal keel at division of trachea into main bronchi. Landmark visible with bronchoscope.

Question 435

Rib 1

Answer 435

Immediately inferior to the clavicle; Has an abnormally flattened shape

Question 436

Collateral Pathway to Right Atrium

Answer 436

Azygous Vein and Ascending Lumbar veins are collateral pathways to Right Atrium if Superior or Inferior Vena Cava are blocked

Question 437

Types of Smooth Muscle

Answer 437

1) Single-Unit / Visceral | 2) Multi-Unit

Question 438

Determinants of Mean Arterial Pressure

Answer 438

1) Cardiac Output 2) Systemic Vascular Resistance 3) Central Venous Pressure

Question 439

Origin of Phrenic Nerve

Answer 439

Ventral/Anterior Rami of C3-C5

Question 440

Muscular Interventricular Septal Defect

Answer 440

Less common VSD. Spontaneously closes/resolves during childhood

Question 441

Systolic Pressure

Answer 441

Pressure at top of pulse

Question 442

(ECG) Orthodromic AVRT

Answer 442

* Most common PSVT for WPW patients * NO DELTA WAVE * Retrograde (not hidden) P wave via Accessory Pathway (occur after QRS) * QRS width normal * ventricles exclusively depolarized via normal pathway

Question 443

Pregangliongic Cell Bodies of Parasympathetic Division (Location)

Answer 443

* CN Nuclei III, VII, IX, X | * Gray Matter of Spinal Cord S2-S4

Question 444

(Jugular Venous Pulse Graph) C Wave

Answer 444

Interrupts X descent on an A wave. Produced when Tricuspid Valve closes and bulges into atrium during onset of Isovolumetric Ventricular Contraction

Question 445

Ribs articulating with sternum via costal cartilages

Answer 445

Ribs 1-7

Question 446

Transersus Thoracis

Answer 446

Course obliquely, deep to Internal Thoracic vessels. Originate from posterior aspect of xiphoid process. Fibers cross 1-2 intercostal spaces.

Question 447

(ECG) Polymorphic Ventricular Tachycardia

Answer 447

* Wide QRS continually changing * Irregular rate * Cause: Multiple ectopic foci or continually changing reentry circuit

Question 448

Impalpable Ribs

Answer 448

1, 11, 12

Question 449

Formed from Proximal Part of Aortic Arch 6

Answer 449

Left and right pulmonary arteries

Question 450

Effects of Sympathetic Stimulation in Heart

Answer 450

Positive chronotrophy, dromotropy, and inotropy.

Question 451

Phospholambin

Answer 451

Protein found in Sarcoplasmic Reticulum Membrane. When unphosphorylated, it inhibits Calcium uptake by SERCA. Phosphorylation increases Ca uptake.

Question 452

(ECG) Acute Non-ST Segment Elevation Myocardial Infarction (non-STEMI)

Answer 452

Not all myocardial infarctions result in ST elevate and Q waves. These are a result of acute partially occlusive coronary thrombus. Only subendocardial layers of myocardium damaged * ST segment depression AND/OR * T wave inversion

Question 453

Atrioventricular Canal

Answer 453

Junction between Primitive Atrium and Primitive Ventricle. Later divided by Dorsal and Ventral Endocardial Cushions fusing into AV Septum. This forms Right and Left AV Canals

Question 454

(ECG) Transient Myocardial Ischemia

Answer 454

Among most important ST Segment / T Wave abnormalities. Usually Coronary Artery Disease -related. * Transient ST Segment depression * T Wave flattening or inversion

Question 455

A normal T wave should be...

Answer 455

Positive in all three bipolar limb leads

Question 456

Plasticity of smooth muscle

Answer 456

maximum tension variable for a given length

Question 457

Maximum Lymph Flow Rate

Answer 457

Rising interstitial pressure will at some point compress lymphatic vessels, impeding flow. Otherwise normally, increased interstitial pressure increases lymph flow

Question 458

Sweating and Heat Acclimatization

Answer 458

Basically, you end up secreting Aldosterone and your sweat is more dilute champ

Question 459

Leukotrienes

Answer 459

Vasoconstrictor

Question 460

Stimulate Release of Vasopressin/ADH

Answer 460

1) Angiotensin II 2) Hyperosmolarity 3) Decreased atrial firing (usually from hypovolemia) 4) Sympathetic activation

Question 461

Insensible Water Loss

Answer 461

Fluid lost daily via lungs, skin, and respiratory tract, as well as feces

Question 462

Development origin of Superior Vena Cava

Answer 462

Terminal part of Right Anterior Cardinal vein and Right Common Cardinal vein form Superior Vena Cava

Question 463

Stroke Volume (SV)

Answer 463

Volume of blood ejected from ventricles during single contraction SV = EDV - ESV

Question 464

Cardiac muscle nuclei

Answer 464

usually one one per cells; maybe 2

Question 465

Effects of Acute Ischemia on Action Potentials

Answer 465

1) Reduce resting membrane potential 2) shorten duration of AP 3) decreased rate of rise and amplitude of Phase 0

Question 466

Thermodilation Method

Answer 466

Clinical Technique to Measure Cardiac Output Specialized catheter (Swanz-Ganz Catheter) with multiple lumens and balloon tip inserted into systemic vein (Internal Jugular or Subclavian). Threaded through the right side of the heart, with its tip lying in the pulmonary artery. A cold saline solution of known temp/vol injected into R atrium to decrease blood temp. Magnitude of temperature change determines blood mixing. Computer calculates Right Ventricular Cardiac Output

Question 467

External Work (EW)

Answer 467

Area circumscribed by PV-Loop

Question 468

Sinus Venarum

Answer 468

Smooth-walled part of Right Atrium. Origin is the right horn of sinus venosus.

Question 469

Effect of Infrathoracic Pressure on Cardiac Function

Answer 469

Inspiration increases the pressure gradient for venous return to the Right Atrium. Expiration does the opposite. Net Effect: Increase in Venous Return

Question 470

Three Cardinal Veins function in early embryo

Answer 470

Anterior and Posterior Cardinal veins drain cephalic and caudal parts of early embryo. Both empty into Common Cardinal Vein which drains into Sinus Venosus

Question 471

Ejection Murmur

Answer 471

Abnormal sound created by opening of Semilunar Valves during systole. Caused by Stentotic Valve

Question 472

(Fast Response Action Potential Receptors) Phase 1

Answer 472

Partial repolarization by potassium efflux, through voltage-gated potassium channels

Question 473

Pulmonic Valvular Incompetence

Answer 473

Valve doesn't close properly due to thickened/inflexible free margins of cusps. Blood flows back into right ventricle from pulmonary trunk. Heard as a heart murmur

Question 474

LQT2

Answer 474

Type of Long QT Syndrome. Mutations lead to defective Kr channel (current reduced). Symptoms triggered by stress and rest. Arrhythmic events more likely to be triggered by sudden loud noises.

Question 475

Diastolic Pressure

Answer 475

Pressure at lowest point of each pulse

Question 476

(Jugular Venous Pulse Graph) V Wave

Answer 476

Upward inflection caused by filling of R Atrium. Venous collection with a closed Tricuspid Valve

Question 477

Coarctation of Aorta

Answer 477

Narrowing of the Aorta superior (Preductal Coarctation) or inferior (Postductal Coarctation) to the entrance of the Ductus Arteriosus

Question 478

Paired Endocardial Heart Tubes

Answer 478

Form from Splanchnic Mesoderm. They later come dorsal to the pericardial coelom as a result of head folding of the embryo

Question 479

Sinus Bradycardia

Answer 479

Decreased firing of the SA node (below 60 BPM) results in slowing of normal heart rhythm. Normal P wave and QRS complexes, however. Normal benign in many at rest or during sleep. Pathologically can result from: * Intrinsic: Aging, Ischemic Heart Diseases, Cardiomyopathy * Extrinsic: Drugs (beta-blockers) and metabolic causes (hypothyroidism) Pronounced reduction: fatigue, light-headedness, confusion, and syncope

Question 480

Radioactive Labeling to determine Cardiac Output

Answer 480

Blood (either RBCs or albumin) labeled with radionuclides, such as technetium-99. Detected by a camera. Volume is estimated by the intensity of radioactivity. Radioactivity of ESV and EDV compared.

Question 481

Overdrive Suppression

Answer 481

Suppression of pacemaker activity in secondary pacemakers. Ectopic pacemakers hyperpolarized when heart rate is greater than intrinsic rate. Higher frequency APs stimulate activity of Na+/K+-ATPase. High sodium concentration from the APs increases pump activity -> hyperpolarizing current Decreases rate of spontaneous depolarization

Question 482

Chronotropy

Answer 482

Cardiac rate

Question 483

(ECG) Atrial Premature Beats (APB)

Answer 483

* Pacemaking originates from atrial focus outside of the SA node * asymptomatic; may cause palpitations * early-than-expected P Wave with abnormal shape * Normal QRS * can happen in healthy people

Question 484

Unpaired Vitelline Arteries

Answer 484

To yolk sac derivatives... 1) Esophageal Arteries 2) Bronchial Arteries 3) Celiac, Superior, and Inferior Mesentary Arteries

Question 485

Ganglion from which Splanchnic Nerves Emanate

Answer 485

Pre-Aortic Ganglion

Question 486

Pulmonary Stenosis

Answer 486

Narrowing of pulmonary orifice due to fusion of free margins of cusps by disease processes. Result is right ventricular hypertrophy, as it must work harder to pump blood to lungs

Question 487

Media

Answer 487

Middle layer of vasculature. Ratio of contents determines properties. Contains... 1) Smooth Muscle Cells 2) Matrix of collagen 3) Elastin 4) Various glycoproteins

Question 488

Thoracostomy

Answer 488

Draining fluid/air from pleural cavity surrounding lungs. Chest tube is placed immediately above a rib to avoid damage to neurovasculature Done at Midaxillary Line of 5th intercostal space

Question 489

Ductus Arteriosus

Answer 489

Wide muscular vessel connecting pulmonary arterial trunk to descending aorta. Under circulating influence of prostaglandin E2 (helps keep it open)

Question 490

Atrioventricular Bundle

Answer 490

Pierces the fibrous rings separating atria from ventricles. Passes through membranous part of Interventricular Septum. Divides into Right and Left AV Bundles, coursing along muscular part of interventricular septum

Question 491

Factors Affecting Body Heat Production

Answer 491

1) Basal Metabolic Rate 2) Muscular Activity 3) Hormones 4) Thermic Effect of Food

Question 492

Vertebral Level: Esophageal Hiatus

Answer 492

T10

Question 493

Circumflex Branch of Left Coronary Artery

Answer 493

Courses in Left Atrioventricular Sulcus. Can anastomose with termination of R Coronary Artery on Posterior Heart. Supplies Left Heart

Question 494

Actively Developed Pressure

Answer 494

Difference between Diastolic and Systolic Pressure at any point of a pressure-volume plot

Question 495

Role of Left Vagus on Heart

Answer 495

Primarily inhibits AV Conduction

Question 496

Midclavicular Line

Answer 496

Passes through midpoint of each clavicle

Question 497

(ECG "hints") Lead V6

Answer 497

QRS complex typically begins with narrow Q wave followed by large R wave

Question 498

Infundibulum (Conus Arteriosus)

Answer 498

Superior, cone-shaped, smooth-walled part of Right ventricle. Inferior to the Orifice of the Pulmonary Trunk

Question 499

Dilated Cardiomyopathy (DCM)

Answer 499

Most common cardiomyopathy. Symptoms include: shortness of breath, swelling of feet/ankles, and fatigue. Left ventricular enlargement and reduced ejection fraction. Mutations negatively affect ability of L Ventricle to contract. Muscles stretch and become thinner. Heart weakness can cause heart failure over time,

Question 500

Describe origin of Anterior Intercostal Arteries

Answer 500

* Upper 6: Internal Thoracic Artery * 7-9: Musculophrenic Artery * 10-11: none

Question 501

Contents of Intercostal Spaces

Answer 501

Intercostal muscles and neurovascular bundle

Question 502

Primary Regulation of Coronary Flow

Answer 502

Changes in tissue metabolism. * Adenosine - dilates during hypoxia or elevated metabolic rate * Nitric Oxide - flow-dependent vasodilation

Question 503

Location of Atrioventricular Node

Answer 503

Inferior part of Interatrial septum, superior to orifice of Coronary Sinus

Question 504

σ = 1

Answer 504

Capillary completely impermeable

Question 505

Posterior Part of Right Atrium

Answer 505

Smooth-walled. Receives the two Vena Cavae and Coronary Sinus. Contains the fossa ovalis

Question 506

Persistent Atrioventricular Canal

Answer 506

Failure of endocardial cushion fusion. Defects in the Atrial and Ventricular Septa. Single Atrioventricular orifice

Question 507

Early Afterdepolarizations

Answer 507

Type of triggered activity leading to tachycardia. Positive change in membrane potential interrupts normal repolarization. More likely in conditions prolonging action potential duration Triggered action potentials can be self-perpetuating and lead to tachyarrhythmia

Question 508

Sympathetic Chain Ganglia

Answer 508

Also called Paravertebral Located in Sympathetic Trunk. Adjacent to vertebral column from C1-Coccyx

Question 509

Innervation types in Intercostal Nerves

Answer 509

1) Somatic Motor 2) Somatic Sensory 3) Postganglionic Sympathetic Fibers

Question 510

Chylothorax

Answer 510

Lymph and chyle (milky fluid) from intestines in pleural cavity. Happens from a tear in Thoracic Duct

Question 511

Counting complexes in time (Calculating Heart Rate)

Answer 511

Often 3 second or 6 second markers on ECG. Count number of QRS complexes. If in 3 second, multiply by 20. If 6 second, multiply by 10.

Question 512

Bachmann Bundle

Answer 512

Branch of Anterior Internodal Tract connecting right and left atria electrically

Question 513

Pericardium

Answer 513

Membranous sac composed of outer fibrous membrane and inner serous membrane. Covers heart

Question 514

Causes of Murmurs

Answer 514

1) Stenosis of valve 2) Regurgitation 3) ejection of blood into dilated chamber 4) Increased blood flow in normal structures (bruit) 5) abnormal shunting 6) Valve disease

Question 515

(ECG) Right Ventricular Hypertrophy

Answer 515

* Chest Leads V1 and V2 (overlying R Ventricle) record larger upward deflection. * R wave becomes taller than S wave * Mean axis shift right.

Question 516

Pathway to Formation of Angiotensin II

Answer 516

1) Renin released by Kidney 2) Renin acts on Angiotension, synthesizing Angiotensin I 3) Angiotensin I converted to Angiotensin II by Angiotensin-Converting Enzyme (ACE)

Question 517

(ECG) Hypokalemia

Answer 517

Abnormality of Myocyte Repolarization. * ST Depression * Flattened T * PROMINENT U WAVE

Question 518

Types of Supraventricular Arrhythmias (Tachyarrhythmia)

Answer 518

1) Sinus Tachycardia 2) Atrial Premature Beats (APB) 3) Atrial Flutter 4) Atrial Fibrillation 5) Paroxysmal Supraventricular Tachycardias (PSVTs)

Question 519

Esophagus

Answer 519

Extends from pharynx through super and posterior mediastina. Ends at stomach. Courses between trachea and vertebral column, then through the Esophageal Hiatus in Diaphragm

Question 520

Abnormal Automaticity

Answer 520

Mechanism of Tachycardia. Cardiac tissue injury induces myocardial cells outside specialized conduction system to acquire automaticity. Ectopic beat/rhythm. Possible Mechanisms: 1) Leaky membrane after myocyte injury; resting potential less negative 2) membrane potential > -60 mV, gradual Phase 4 depolarization possible

Question 521

Chemical Thermogenesis

Answer 521

Uncoupling of Oxidative Phosphorylation in brown fat. Increased metabolic rate produces heat. Acute from: Catecholamine Release Chronic: Hyperthyroid function

Question 522

Steps of Cross-Bridge Cycling in Smooth Muscle

Answer 522

1) ATPase on globular head of myosin hydrolyzes ATP -> ADP + Pi 2) Myosin head binds actin 3) Release of ADP+Pi causes head to turn; "ratchet movement" 4) Actin released when ATP binds myosin

Question 523

Manners of body heat loss

Answer 523

1) Radiation (Major) 2) Conduction (to objects/with air) 3) Convection 4) Evaporation

Question 524

Great Cardiac Vein

Answer 524

Tributary of Coronary Sinus. Begins in anterior part of Interventricular Sulcus. Courses posteriorly intro Atriventricular Sinus (continues as Coronary Sinus). Drains area supplied by Left Coronary Artery

Question 525

Phases of Cardiac Cycle associated with Ventricular Systole

Answer 525

Phase 2-4

Question 526

White Ramus Communicans

Answer 526

Neural structure in which Sympathetic Preganglionic Axons leave Ventral Rami destined for Sympathetic Chain or Pre-Aortic Ganglia

Question 527

Closed Pneumothorax

Answer 527

Rupture of superficial air sacs in lungs. Tearing of visceral pleura. Air within respiratory passages (high pressure) can now enter pleural cavity (low pressure)

Question 528

Short QT Syndrome (SQTS)

Answer 528

Accelerated cardiac repolarization and shorter refractory period. Shoter QTc than normal (<= .33 sec males, <= .34 females) Causes: 1) Gain-of-Function mutations in Kr, Ks, and K1 (inward rectifying) channels 2) Increased efflux of potassium during repolarization phase Symptoms: 1) Dizziness 2) atrial or ventricular fibrillation 3) sudden death

Question 529

Pleural Recess

Answer 529

Narrow region of Pleural Cavity where parietal pleura folds and contacts parietal pleura from another region

Question 530

Myocardial Infarctions and the Q Wave

Answer 530

Q Wave: * More prominent (activation of healthy opposite unopposed) * Width >= 1 * Depth of >25% total QRS height * Develops in leads overlying infarction (must be in group of leads, not just one)

Question 531

Required for sustained contraction of smooth muscle

Answer 531

extracellular calcium

Question 532

Elastic Potential Energy

Answer 532

Area to left side of PV-Loop, bracketed by ESPVR and EDPVR

Question 533

Atrial Septum (origin)

Answer 533

Fusion of Septum Secundum and (lower part) Septum Primum

Question 534

Span of Intercostal Muscles

Answer 534

Rib above to rib below (one)

Question 535

Net Flux Across Capillaries

Answer 535

J = Kf * (A)(NDF) J: net fluid flux Kf: Filtration constant A: Surface area for exchange NDF: net driving force

Question 536

Pericardiocentesis

Answer 536

Procedure to alleviate Pericardial Effusion. Two methods 1) Needle inserted parasternally in left 4th/5th intercostal space 2) Needle inserted left of xiphoid processed, angled posterior/superiorly 45 degrees

Question 537

Located smooth muscle primarily found

Answer 537

hollow organs and tubes

Question 538

Sources of blood for Splanchnic Circulation

Answer 538

1) Celiac Artery 2) Superior Mesenteric Artery 3) Inferior Mesenteric Atery

Question 539

Superior to Inferior Order of Intercostal Neurovascular Bundles

Answer 539

Vein, (posterior) Artery, Nerve (Mnemonic: VAN)

Question 540

Mechanisms increasing Stroke Volume

Answer 540

1) Sympathetic Stimulation of heart (enhanced atrial and ventricular contractility) 2) Venous return increase via skeletal muscle contraction and respiration 3) Enhanced venous constriction 4) Increased Rate of Lusitropy (cardiac muscle relaxation)

Question 541

Eustachian Valve

Answer 541

Tissue flap at Inferior Vena Cava and Right Atrium Junction. Directs blood through Foramen Ovale to Left Atrium.

Question 542

Function of Subcostal Muscles

Answer 542

depress Ribs

Question 543

Structures in Esophageal Hiatus

Answer 543

1) Esophagus | 2) Right and Left Vagal Nerve Trunks

Question 544

LQT3

Answer 544

Defective fast inactivating Na channel. Inward sodium current increased. Syncope of cardiac arrest more likely to happen during sleep or inactivity

Question 545

Sources of blood to Sinus Venosus

Answer 545

1) Paired umbilical veins (placenta) 2) Paired Vitelline Veins (yolk sac - future gut) 3) Paired Common Cardinal Veins (from remainder of embryo)

Question 546

Functions of Atrial Natriuretic Peptide (ANP)

Answer 546

Decreases... 1) renin 2) angiotensin II 3) aldosterone 4) blood volume 5) central venous pressure 6) arterial pressure

Question 547

Primary Resistance Vessels

Answer 547

Primary Resistance vessels regulating arterial blood pressure and flow within organs are smaller arteries and arterioles

Question 548

Types of Capillaries (sorted by bulk flow properties from least to greatest permeability)

Answer 548

1) Continuous Capillaries 2) Fenestrated Capillaries 3) Discontinuous Capillaries

Question 549

Torsade de Pointes

Answer 549

Ventricular tachycardia characterized by a change in amplitude and the twisting of QRS Complexes

Question 550

Double Aortic Arch

Answer 550

Develops in addition to normal left aortic arch. Due to persistence of Distal pt of R Dorsal Aorta. Forms a vascular ring around trachea/esophagus and causes difficulty in swallowing/breathing.

Question 551

Augmented Unipolar Leads

Answer 551

Two limbs connected to a (-) terminal. third to a positive. Leads aVR, aVL, aVF

Question 552

Innervation of Right Phrenic Nerve

Answer 552

1) Muscles of Right Dome of Diaphragm | 2) Central part of Diaphragmatic Pleura/Peritoneum

Question 553

Hypothermia

Answer 553

Results in general slowing of metabolism and of cardio/neuronal excitability * Temperature hits 94F - thermoregulation impaired * Temperature below 85 - thermoregulation lost * Temperature ~77 - Death due to heart standstill or fibrillation

Question 554

Delayed Afterdepolarizations

Answer 554

Type of triggered activity leading to tachycardia. May appear shortly after repolarization complete. Most common in states of increased intracellular Calcium. Also can be self-perpetuating and lead to tachyarrhythmia

Question 555

NDF > 0

Answer 555

Net Driving Force > 0 Indicates filtration

Question 556

Proteins in myofilament sarcomere

Answer 556

1) actin 2) myosin 3) tropomyosin 4) troponins 5) titin

Question 557

Conditions DIRECTLY altering (shifting) venous return curves

Answer 557

1) change in blood volume 2) change in venous tone 3) resistance to venous return

Question 558

Junctional Escape

Answer 558

Escape Rhythm arising from AV node or Proximal Bundle of His. Can happen under moderate parasympathetic stim.

Question 559

Atrial Internodal Tracts

Answer 559

Specialized myocytes serving as conduction pathways between SA node and AV node. 1) Anterior Internodal Tract 2) Middle Internodal Tract 3) Posterior Internodal Tract

Question 560

Plurae

Answer 560

continuous layer covering lungs, air tubes, and bloodvessels to lungs and thoracic wall

Question 561

Thromboxane

Answer 561

Vasoconstrictor

Question 562

Effect of Sympathetics on Cerebral Circulation

Answer 562

Has little effect actually. Autoregulation due to changes in arterial pressure is the dominant force. Very highly regulated, I might add. Gotta keep a tight hold on these things in the brain cuz

Question 563

(ECG) Ventricular Pre-Excitation Syndrome

Answer 563

* aka Wolff-Parkinson-White Syndrome (WPW) * predisposition to PSVTs (accessory pathway can become loop) * Atrial impulse can move to ventricle both via AV node and Accessory Pathway (faster) * Ventricles stimulated earlier than normal * short PR Interval (<0.12 seconds) * QRS complex "slurred" -- called a Delta Wave * QRS widened

Question 564

Cisterna Chyli

Answer 564

Dilated lymph sac inferior to diaphragm. Drains into Thoracic Duct

Question 565

Cardio-Thoracic Ratio

Answer 565

Widest diameter of the heart compared to the widest internal diameter of the Thoracic Cage. Normal CTR is <50% in normal adults

Question 566

Dextrocardia with Situs Inversus

Answer 566

Dextrocardia with inversion of other viscera

Question 567

Components of Definitive Ventricular Septum

Answer 567

1) Muscular Ventricular Septum | 2) Membranous Ventricular Septum

Question 568

Superior Vena Cava Syndrome

Answer 568

Bronchogenic tumor of R Lung compresses Superior Vena Cava. Venous blood from head/neck/upper limbs difficulty returning. Bulged Internal/External Jugular Veins and tributaries of Subclavian in upper R limb. Venous blood bypasses SVC traveling inferiorly to Azygous Vein. Azygous Vein -> Ascending Lumbar Vein -> Lumbar Vein > IVC

Question 569

Chemoreceptor Reflexes

Answer 569

Result of activity of arterial chemoreceptors, located in Carotid Arteries and Aortic Arch. There are also 'Central Chemoreceptors' in the CNS. Respond to decreased PO2, decreased pH, and/or increased PCO2 in arterial blood. Response: increase breathing and mean arterial pressure

Question 570

Continuous Capillaries

Answer 570

Tight endothelium and continuous basement membrane. Least permeable type.

Question 571

Inferior Mediastinum

Answer 571

Located between body and xiphoid process of sternum (anteriorly) - and lower 8 thoracic vertebrae (posteriorly)

Question 572

Lymph Trunks draining into Thoracic Duct from upper body

Answer 572

1) Left Jugular 2) Left Subclavian 3) Left Bronchomediastinal

Question 573

Aortic Sinus

Answer 573

Space between each cusp and wall of ascending aorta. Openings to R/L coronary arteries lead from same-named cusps/sinuses. Fill with blood during diastole when there's flowback from Ascending Aorta. Cusps close valve and blood enters coronary arteries.

Question 574

Silhoutte Sign

Answer 574

Elimination of the silhouette or loss of lung/soft tissue interface caused by a mass or fluid in the normally air-filled lung

Question 575

Aortic Valve

Answer 575

Similar to pulmonary valve. Three semilunar cusps (Posterior/Non-coronary, right, and left). Has the Aortic Sinus

Question 576

Anatomical Reentry

Answer 576

Unidirectional block and reentry occurring over anatomically-fixed path. Usually appears as monomorphic tachycardia on ECG. Examples: * AV Nodal Reentrant Tachycardia (AVNRT) * Atrioventricular Reentrant Tachycardias (AVRT) * Atrial Flutter

Question 577

Functional Conduction Block

Answer 577

Area unexcitable because cardiac cell still refractory. Ex: Antiarrhythmic drugs induce this condition by prolonging APs

Question 578

Membranous Interventricular Septal Defect

Answer 578

Failure of fusion of 3 structures forming the Membranous Interventricular Septum. Blood flows from L to R Ventricle. Shunt increases pulmonary blood flow and causes severe pulmonary disease

Question 579

Cardiac Notch

Answer 579

Indentation in anterior border of left superior lobe of lungs. Due to deviation of hearts apex to left side.

Question 580

(ECG) Atrioventricular Nodal Reentrant Tachycardia (AVNRT)

Answer 580

* Most common form of PSVTs in adults * normal QRS complex * P wave hidden in QRS (retrograde atrial depolarization happens simultaneously with ventricles)

Question 581

Functional Reentry

Answer 581

Unidirectional block and reentry not requiring fixed path and occurring in electrically heterogeneous myocardium. Waves continually change direction (Spiral Waves) Examples: * Polymorphic Ventricular Tachycardia * Atrial Fibrillation * Ventricular Fibirilation

Question 582

Sternopericardial Ligaments

Answer 582

Teather anterior surface of pericardium to sternum

Question 583

Sympathetic Nerves Effect on Heart

Answer 583

Increased heart rate. Increased contractility. Dilates coronary arteries.

Question 584

Open Pneumothorax

Answer 584

Happens from a penetrating wound to Thoracic Wall. Air enters pleural cavity since atmospheric pressure > intrathoracic pressure

Question 585

(ECG) Monomorphic Ventricular Tachycardia

Answer 585

* Wide QRS Complex * Rate 100-200 bpm * QRS complexes identical and rate is regular * Reentry circuit, often from myocardial scar or cardiomyopathy

Question 586

Left Axis Deviation

Answer 586

Mean Electrical Axis of less than -30

Question 587

Anteroseptal Myocardial Infarction (Leads and Typical Artery)

Answer 587

Leads V1-V2 Left Anterior Descending Coronary Artery

Question 588

Bicuspid (Mitral) Valve

Answer 588

Guards left Atrioventricular orifice in the Left Ventricle. Composed of Anterior and Posterior Cusps. Cusps commonly affected by Ca deposits in Rheumatic Fever. Stick together and lead to valve incompetency and a heart murmur.

Question 589

Allows placental venous flow to bypass Hepatic Circulation

Answer 589

Ductus Venosus (enters Inferior Vena Cava with deoxygenated blood)

Question 590

Normal Duration of P Wave

Answer 590

0.08-.10 seconds 2-2.5 boxes

Question 591

Inferior Myocardial Infarction (Leads and Typical Artery)

Answer 591

Leads II, III, aVF Right Coronary Artery

Question 592

Posterior (Base) Surface of Heart

Answer 592

Mostly left atrium

Question 593

Echocardiography

Answer 593

Measures changes in volume of heart chambers

Question 594

Internal Intercostal Membrane

Answer 594

Thin aponeurosis replacing internal intercostal muscles in POSTERIOR part of each intercostal space.

Question 595

Gap in Diaphragm where Superior Epigastric Artery Passes

Answer 595

Sternocostal Hiatus

Question 596

Coronary Arterial Dominance

Answer 596

Relates to source of Posterior Interventricular Artery. Either from Right or Left Coronary Artery. From R: Branch of R Coronary Artery (67% pop.) From L: Branch of Circumflex Branch

Question 597

Tract of Wenckebach

Answer 597

Another name for Middle Internodal Tract

Question 598

Sweat

Answer 598

You know what it is bro. Osmolar concentration below plasma. Made up of NaCL mainly. Trace amounts of potassium, urea, and lactate.

Question 599

Ways to Express Ventricular Performance on Frank-Starling Curve

Answer 599

1) Stroke Volume | 2) Cardiac Output

Question 600

Stroke Work

Answer 600

Work done by ventricle to eject a volume of blood. Estimated by: L Ventricle - SW = SV * Mean Aortic Pressure R Ventricle - SW = SV * Mean Pulmonary Artery Pressure

Question 601

Types of Mutations in Long QT Syndrome

Answer 601

1) LQT1 (defective Ks channel) 2) LQT2 (defective Kr channel) 3) LQT3 (defective fast inactivating Na Channel)

Question 602

Innervation of Parietal Pleura

Answer 602

1) Intercostal Nerves (Costal Pleura and peripheral pt of diaphragmatic pleura) 2) Phrenic Nerve (mediastinal pleura and central part of diaphragmatic pleura)

Question 603

Automaticity

Answer 603

Ability of heart to initiate own beat

Question 604

Origin of Intercostal Nerves

Answer 604

Ventral Rami of T1-T11

Question 605

Third Heart Sound (S3)

Answer 605

Occurs in early diastole during passive ventricular filling. May be normal (if present) in young people but it's a sign of heart failure in adults > 40 Caused by blood hitting the Ventricular Wall

Question 606

Innervation of Post-Ganglionic Adrenergic Nerves from the Rostral Ventrolateral Medulla (RVLM)

Answer 606

1) SA + AV Nodes 2) Conduction Pathways 3) Myocardium Effect: Vasoconstriction / Tachycardia

Question 607

Causes of Left Axis Deviation

Answer 607

1) Inferior Wall Myocardial Infarction 2) Left Anterior Fascicular Block 3) Left Ventricular Hypertrophy (sometimes)

Question 608

Vertebral Level: Caval Opening

Answer 608

T8

Question 609

Specialized epithelium found in plurae, peritoneum, and pericardium

Answer 609

mesothelium

Question 610

Parasternal Hernia (Foramen of Morgagni)

Answer 610

Abdominal viscera herniated through Sternocostal Hiatus surrounding the Superior Epigastric Artery. Hiatus abnormally enlarged due to developmental issues of small part of muscles of diaphragm. Rare.

Question 611

Anterior Median (Midsternal) Line

Answer 611

Passes through the center of the sternum. Intersects median plan with Anterior Thoracic Wall.

Question 612

Sternal Puncture (what is it and where is it done)

Answer 612

Body of the Sternum. Done to obtain bone marrow sample.

Question 613

Activated byCa2+-Calmodulin complex in smooth muscle

Answer 613

Myosin Light Chain Kinase (MLCK)

Question 614

(ECG) Antidromic AVRT

Answer 614

* Wide QRS complex * retrograde P Wave (via AV node) * Complete anterograde conduction happens via Accessory Pathway

Question 615

Internal Intercostal Muscle

Answer 615

Arranged at 90 degree angle to External Intercostal layer. Most active during expiration.

Question 616

Forms Left Subclavian Artery

Answer 616

ONLY Left 7th Intersegmental Artery

Question 617

Double Superior Vena Cava

Answer 617

Terminal part of left anterior cardinal vein that normally degenerates persists

Question 618

Parietal Pleura

Answer 618

Outer wall of cavity

Question 619

Neural Areas Regulating Cardiovascular Function

Answer 619

1) Medulla (Reticular formation of ventrolateral medulla and lower 1/3 pons) 2) Hypothalamus 3) Cerebral Cortex

Question 620

Congenital Diaphragmatic Hernia (Foramen of Bochdalek)

Answer 620

Herniation of abdominal organs into pleural cavity, due to a defect in diaphragm. Failure of Pleuroperitoneal Membrane to form or fuse properly with other contributors to diaphragm. Compression of lungs if defect is large. Lungs are hypoplastic (underdeveloped) and dysfunctional. High mortality rate

Question 621

Phases of Cardiac Cycle

Answer 621

1) Atrial Systole 2) Isovolumetric Contraction 3) Rapid Ejection 4) Reduced Ejection 5) Isovolumetric Relaxation 6) Rapid Filling 7) Reduced Filling (Diastasis)

Question 622

Blood supply to Anterior Abdominal Wall

Answer 622

Superior Epigastric Artery

Question 623

Aortic Arch 3

Answer 623

Proximal pt: Forms Common Carotid Artery Distal pt: 1) Internal Carotid Artery (along with pt of Dorsal Aorta) 2) External Carotid Arteries

Question 624

Location of division of Internal Thoracic Artery into terminal branches

Answer 624

level of 6th intercostal space

Question 625

Branches of Right Coronary Artery (Proximal to Distal)

Answer 625

1) Sinu-Atrial Nodal Branch 2) Marginal Artery 3) AV Nodal Artery 4) Posterior Descending Artery (Posterior Interventricular Branch)

Question 626

Types of Ribs

Answer 626

1) True Ribs 2) False Ribs 3) Floating Ribs

Question 627

Factors Affecting Preload

Answer 627

1) Total Blood Volume 2) Venous Tone (alters amount of blood in veins) 3) Atrial Contraction (increases amount of blood in ventricle) 4) Intrathoracic Pressure 5) Body Position 6) Skeletal Muscle Pump 7) Intrapericardial Pressure (build-up of fluid limits cardiac filling)

Question 628

EKG Chest Leads

Answer 628

``` V1 - 4th ICS, 2 cm R of Sternum V2 - 4th ICS, 2 cm L of Sternum V3 - Midway between V2 + V4 V4 - 5th ICS, L Midclavicular Line V5 - 5th ICS, L Anterior Axillary Line V6 - 5th ICS, L Midaxillary Line ```

Question 629

Thyroxine

Answer 629

Effect on all cells to increase local metabolic rate upto 100% of basal. Heating effect on body

Question 630

Layers of (large) blood vessels (superficial to deep)

Answer 630

1) Intima 2) Media 3) Adventitia

Question 631

β2-Adrenergic Receptors and Epinephrine levels

Answer 631

Arterioles in specific organs have β2 receptors mediating vasodilation. They are more sensitive to epinephrine than α1 receptors. Moderate levels of epinephrine: vasodilation (β2) Higher Levels: vasoconstriction (α1)

Question 632

Everything is negative in this lead

Answer 632

aVR

Question 633

Structures Visible in Main Pulmonary Artery Level

Answer 633

1) Pulmonary Trunk 2) R/L Pulmonary Arteries 3) R/L Main Bronchi 4) Superior Vena Cava 5) Ascending Aorta 6) Descending Aorta

Question 634

Sympathetic Nervous Control: Coronary Arteries

Answer 634

Leads to transient vasoconstriction but then unlike other vessels, dilation. Increased heart rate and inotropy leads to production of vasodilator metabolites. "Functional Sympatholysis"

Question 635

Postganglionic Cell Bodies of Parasympathetic Division (Location)

Answer 635

Terminal Ganglia

Question 636

Baroreceptor Reflex

Answer 636

Powered by stretch receptors in the walls of the heart/vessels. Stimulated by distention. Found in abundance in Carotid Sinus (via: CN IX) and Aortic Arch (via: CN X). Monitor arterial pressure. Tonically active at normal pressure. Firing rate increases with pressure. Net Effect: Vasodilation of peripheral vessels and decreased rate of cardiac contraction

Question 637

Paroxysmal Supraventricular Tachycardias (PSVTs)

Answer 637

Sudden onset and termination. Atrial rates 140-250 bpm. Mechanism most often re-entry involving AV node, Atrium or accessory pathway between atrium/ventricle. Most common form is Atrioventricular Nodal Reentrant Tachycardia (AVNRT)

Question 638

Special Case: Posterior Wall Myocardial Infarction and ECG

Answer 638

* No pathological W wave because no electrode in place to identify it. * Leads V1 and V2 record opposite of what hypothetical properly-placed lead would * Taller than normal R waves in V1, V2 * Distinguish from Right Ventricular Hypertrophy (also large R wave in V1, V2) because RVH causes Right Axis Deviation, this does not!

Question 639

QT Interval

Answer 639

Action potential duration. Length of depolarization and repolarization. Beginning of QRS to end of T.

Question 640

Reason for increased risk of sudden death in Long QT Syndrome

Answer 640

Ventricular Fibrillation

Question 641

Subregions of Parietal Pleura

Answer 641

1) Diaphragmatic Part 2) Costal Part 3) Mediastinal Part 4) Cervical Part

Question 642

Treatment for Patent Ductus Arteriosus

Answer 642

Postaglandin Synthesis Inhibitors to promote closure

Question 643

Components of Cardiac Conduction System

Answer 643

1) SA Node 2) AV Node 3) Bundle of His 4) Left/Right Bundle Branches 5) Purkinje Fibers

Question 644

Membranous Part of Interventricular Septum

Answer 644

Thin; located in upper septum, inferior to right + posterior cusps of Aortic valve site of congenital Ventricular Septal Defects (VSD)

Question 645

Esophageal Hiatal Hernia

Answer 645

Stomach herniated through an enlarged Esophageal Hiatus of the Diaphragm. Stomach contents reflux into the esophagus. Esophageo-Gastric sphincter is nonfunctonal. Infants present with vomiting when laid on back

Question 646

Mean Electrical Axis

Answer 646

Average of all of the instantaneous mean electrical vectors occurring during ventricular depolarization

Question 647

Nerve innervating same dermatome as heart

Answer 647

Intercostobrachial Nerve (T2)

Question 648

Fate of Left Horn of Sinus Venosus

Answer 648

Forms the Coronary Sinus

Question 649

Autoregulation (Vessels)

Answer 649

Intrinsic ability of organ to maintain constant blood flow despite change in perfusion pressure

Question 650

Prostacyclin (PGI2)

Answer 650

Vasodilator

Question 651

Right Aortic Arch

Answer 651

Can pass anterior or posterior to esophagus/trachea. Difficulties swallowing/breathing. Due to persistence of entire right dorsal aorta and degeneration of distal part of left dorsal aorta

Question 652

Arachidonic Acid Metabolites

Answer 652

Released as Endothelial-Derived Factors 1) Prostacyclin (PGI2) 2) Thromboxane 3) Leukotrienes

Question 653

(ECG) First Degree AV Conduction System Block

Answer 653

* PR interval is lengthened ( >0.2 seconds) | * benign, asymptomatic

Question 654

Pyothorax

Answer 654

pus in pleural cavity

Question 655

Capillary Hydrostatic Pressure (Pc)

Answer 655

Determined by arterial/venous pressures and by precapillary/postcapillary resistance Increased by: * Increase in arterial/venous pressure * Increase in venular resistance Decreased by: * Increase in arteriolar resistance

Question 656

Intercalated Discs

Answer 656

Junctions between cardiac muscle cells with Mechanical and Electrical connections.

Question 657

Trabeculae Carnae

Answer 657

Irregular ridges of muscle that line the Ventricular Lumen

Question 658

Anterolateral Myocardial Infarction (Leads and Typical Artery)

Answer 658

Leads V5-V6, I, aVL Left Circumflex Coronary Artery

Question 659

Pyrogens

Answer 659

Substances causing hypothalamic set point to rise (fever?) ex: Proteins, breakdown products of proteins, lipopolysaccharide toxins

Question 660

Heat Exhaustion

Answer 660

Occurs after excessive loss of salt and water due to sweating and/or venous return being compromised by heavy exertion and maximum cutaneous vasodilation. Body temp may still be normal

Question 661

Innervation of Left Phrenic Nerve

Answer 661

Muscles and central part of diaphragmatic pleura/peritoneum

Question 662

Mean Arterial Pressure

Answer 662

Blood pressure averaged out by time. Approximation: MAP = P(diastolic) + [P(systolic) - P(diastolic)] / 3

Question 663

Destination of Inhibitory Interneuron from Nucleus Tractus Solitarus

Answer 663

Sympathetics in Rostral Ventrolateral Medulla (RVLM)

Question 664

Abnormal Right Subclavian Artery

Answer 664

Branch of the aortic arch and passes posterior to esophagus. (Starts to left of esophagus instead of on right like normal) Can result in kinking of the esophagus. Dysphagia. Result of.. 1) Obliteration of R 4th Aortic Arch and adjacent part of R Dorsal Aorta 2) Abnromal R Subclavian forms from right 7th intersegmental artery and persistence of distal part of R Dorsal Aorta (normally degenerates)

Question 665

Diurnal Variation

Answer 665

Core temperature minimal ini the morning and peaks in the late afternoon

Question 666

(Jugular Venous Pulse Graph) A Wave

Answer 666

Upward wave coinciding with Atrial Systole

Question 667

Structures that pierce Crura of Muscular Diaphragm

Answer 667

1) Greater, Lesser, and Least Splanchnic Nerves | 2) Hemiazygous Vein

Question 668

Thymus Gland

Answer 668

Bilobed lymphoid organ of immune system, located in Superior and Anterior (Inferior) Mediastinum. Becomes fatty remnant in puberty.

Question 669

Pericardial Effusion

Answer 669

Fluid (blood) can build up in pericardial sac due to external fluid pressure on heart. Can cause Cardiac Tamponade (compression by fluid)

Question 670

Deviation in Left Anterior Fascicle Block

Answer 670

Left Axis Deviation

Question 671

Stenosis of Aortic Orifice

Answer 671

Narrowing due to adherence of free margins of cusps

Question 672

Function(s) of Fibrous Skeleton of Heart

Answer 672

1) Attachment site for valves (Anulus fibrosis) 2) Attachment site for cardiac fibers 3) Separates atrial from ventricular cardiac muscle at Atrioventricular Orifice 4) Gives rigidity to orifices

Question 673

Components of Definitive Left Ventricle

Answer 673

1) Trabeculated Part from Primitive Ventricle | 2) Smooth Upper Part (Aortic Vestibule) from Bulbus Cordis

Question 674

Spine Sign

Answer 674

Density of vertebral column (check lateral view) gradually decreases down the spine (becomes darker). Absence of the decrease in density may indicated a mass overlying the vertebrae

Question 675

Form Definitive Arch of Aorta

Answer 675

1) Left Aortic Arch 4 2) Aortic Sac 3) Left Dorsal Aorta

Question 676

(Fast Response Action Potential Receptors) Phase 0

Answer 676

Depolarization by Sodium influx through fast channel Nav1.5

Question 677

Bronchopulmonary Segment

Answer 677

a function surgical/functional unit of lung

Question 678

Aortic Arch 4

Answer 678

* Left Aortic Arch 4: Arch of the Aorta (along w/ aortic sac and left dorsal aorta) * Right Aortic Arch 4: pt of Right Subclavian Artery