A&P: Cardiovascular system; Heart

Question 1

Pulmonary circuit

Answer 1

Right-Sided pump
Receives oxygen-poor blood from system, then pumps it to lungs
Short, low pressure circulation

Question 2

Systemic circuit

Answer 2

Left-Sided pump
Receives oxygenated blood from lung, then pumps it to system
Enters left side of heart, exits aorta, then to whole body
Long, high resistance to blood flow

Question 3

Pericardium

Answer 3

Fibrous pericardium

Serous pericardium

Question 4

Fibrous pericardium

Answer 4

Outermost layer
Dense CT
Protects, anchors, and prevents overfilling of heart with blood

Question 5

Serous pericardium

Answer 5

Deep to fibrous
Parietal layer: below/connected to bottom of fibrous
Continous with visceral layer at pulmonary trunk
Pericardial cavity: between 2 layers; film of serous fluid
Visceral layer: (epicardium); layer just on top of heart muscle (integral part of heart wall)

Question 6

Myocardium

Answer 6

Cardiac muscle
Bulk of heart
Cardiac skeleton: reinforces myocardium and anchors cardiac muscle

Question 7

Endocardium

Answer 7

Simple squamous epithelial tissue
Lines heart chambers
Touches blood
Continuous with endothelium of all blood vessels

Question 8

Atria

Answer 8

2 receiving chambers
(Superior)
Right: receives deoxygenated blood from vena cava and coronary sinus
Left: receives oxygenated blood from lungs
Fill simultaneously, then contract

Question 9

Ventricles

Answer 9

2 heavy duty pumping units
Thick myocardial walls 
(Inferior)
Make up most of heart volume
Right: receives blood from right atrium
Left: received blood from left atrium
Fill simultaneously, then contract

Question 10

Interatrial septum

Answer 10

Separates atrium

Divides heart longitudinally

Question 11

Interventricular septum

Answer 11

Thicker

Separates ventricles

Question 12

Blood enters right atrium via 3 veins:

Answer 12

Superior vena cava: returns blood from body regions superior to diaphragm

Inferior vena cava: returns blood from body areas below diaphragm

Coronary sinus: collects blood draining from myocardium

Question 13

Pulmonary veins

Answer 13

2 right and 2 left

Both carry blood to LEFT atrium

Question 14

Accessory muscles

Answer 14

Trabecular carnae: muscle projections in wall of ventricles; increase strength of contraction

Papillary muscles: help close AV valves; attached to collagen
Contraction –> closure of valves

Question 15

Pulmonary trunk

Answer 15

Right side

Blood goes from right ventricle –> pulmonary think –> pulmonary artery

Question 16

Aorta

Answer 16

Equivalent ot pulmonary trink, except carries oxygen rich blood
Left ventricle –> aorta

Question 17

Fossa ovalis

Answer 17

In interatrial septum
Between septa
Depression that was once a fetal hole connected to atria

Question 18

Atrioventricular valves (AV)

Answer 18

2
Between atrium and ventricle
Prevent back flow into atria when ventricles contract
Right: tricuspid
Left: bicuspid (mitral valve)

Chordae tendoneae: collagen cords attached to papillary muscles on AV flaps
Want AV valves closed when ventricles are contracting, to prevent back flow of blood

Question 19

Semilunar valves (SL)

Answer 19

2
Pulmonary valve
   -Between right ventricle and pulmonary trunk
Aortic valve
   -Between left ventricle and aorta

When ventricles are contracting, semilunar valves are open
Ventricle –> out
Like AV valves, open and close in response to pressure

Question 20

Left coronary artery

Answer 20

Circumflex artery: serves lateral side if heart (left atrium and ventricle)

Anterios interventricular artery: runs down center

• Supplies blood to inter ventricular septum and anterior walls of both ventricles
• LAD: left anterior descending artery

Question 21

Right coronary artery

Answer 21

Marginal artery: serves myocardium of lateral side of ventricle

Posterior interventricular artery: back of heart (posterior ventricle walls)

Question 22

Coronary veins

Answer 22

Collects venous blood

Question 23

Coronary sinus

Answer 23

Drains coronary vessels

Sends blood to right atrium

Question 24

Cardiac output (CO)

Answer 24

Amount of blood pumped out by each ventricle in 1 min

Increases when SV increases and/or heart beats faster

Question 25

Stroke volume (SV)

Answer 25

Volume of blood pumped out by one ventricle with each beat

Question 26

Cardiac reserve

Answer 26

Difference between resting and maximal CO

Question 27

EDV

Answer 27

End diastolic volume Blood volume when ventricles are at rest (after ventricular filling) Higher EDV, higher CO Influenced by: - Ventricular diastole - Venous return: amount of blood transported into R&L atria More return, more blood into ventricles, higher EDV

Question 28

ESV

Answer 28

End systolic volume Residual blood; left over after ventricles contract Influenced by: - Arterial BP Higher the BP, the more difficult for ventricles to eject blood, more ESV leftover -Ventricular systole Harder the ventricles contract, less ESV

Question 29

Preload

Answer 29

Degree of stretch just before systole Increased preload = increased SV Frank-Startling law Increase preload via increased venous return Increased preload, increased EDV, increased strength of contraction

Question 30

Venous return

Answer 30

Amount of blood returning to the heart and distending its ventricles

Question 31

Contractility

Answer 31

Contractile strength achieved at a given muscle length Increased intracellular Ca++ = higher contractility Sympathetic stimuli = higher contractility Positive and negative inotropic agents: + : epinephrine, thyroxine, glucagon - ; adidosis, rising K+ levels and calcium channel blockers Increased contractility = decreased ESV

Question 32

Afterload

Answer 32

Pressure that the ventricles must overcome to eject blood Increase after load, increased ESV, decreased CO, increase SV

Question 33

Arrhythmia

Answer 33

Abnormal heart rate b/c electrical conduction system is out of sync

Question 34

Bradycardia

Answer 34

Depends on individual Less then 60 bp (heartbeat slower than normal) May result from low body them, parasympathetic nervous activation Seen in extremely trained/elite athletes

Question 35

Tachycardia

Answer 35

May result from elevated body temp, stress, certain drugs, or heart disease Resembles someone out of shape Flutter: 200-33 bpm; electrical current is in sync, just very fast Fibrillation: high bp; electrical current is chaotic -Lack of SA node stimulation

Question 36

Heart valves

Answer 36

Heart murmurs - Incompetent valve: (not snapping shut): blood regurgitates --> problems with closing - Stenotic valve: hardening of valve; does not open as wide or close as tight - Prolapsed valve: slipped forward of down

Question 37

IE: Infective endocarditis

Answer 37

``` Fungal infection of the endocardium May be caused by: -Staph -Strept -Candida -Septic blood ```

Question 38

Myocardial infraction (MI)

Answer 38

Heart attack | Cell death due to lack of oxygen

Question 39

Myocardial ischemia

Answer 39

Angina pectoris: blockage with temporary problems Temporary lack of oxygen (myocardiocytes do not receive blood) Can turn into an MI

Question 40

Vascular occlusion

Answer 40

Anything that blocks the flow of blood

Question 41

Cardiogenic shock

Answer 41

Dead myocardiocytes

Question 42

Tumor

Answer 42

Myxoma: most common primary cardiac neoplasm | Usually benign

Question 42

Heart murmur

Answer 42

Incompetent valve: blood regurgitates (problem with valve closing) Stenoic valve: hardening of valve ( doesnt open as wide or close as tight) Prolapsed valve: slipped forward or down