Heart Flashcards
(183 cards)
1
Q
Between which ribs is the heart?
A
Between 3rd and 6th ribs
2
Q
What are the 3 layers of the heart?
A
Endocardium: inner wall
Myocardium: thick muscular wall
Epicardium: visceral serous pericardium
3
Q
What is also known as atria proper for the right heart?
A
Sinus vinarum
4
Q
What are the 2 notable parts in the sinus venarum?
A
Intervenous tubercle
Fossa ovalis
5
Q
What are the 2 notable things in the right auricle?
A
Pectinate muscle
Crista terminalis
6
Q
What are the 5 places that the right atrium receive blood from?
A
Cranial vena cava
Caudal vena cava
Azygos vein
Coronary sinus
Small cardiac veins
7
Q
How many papillary muscles are in the right ventricle
A
3
8
Q
How many pulmonary veins does the left atrium receive blood from?
A
5-6
9
Q
What structure of the foramen ovale is left in the left atrium?
A
The valve of the foramen ovale
10
Q
Where is the cranial scapular angle?
A
Spinous process of T1
11
Q
Where is the caudal scapular angle?
A
Spine bodies of T4-T5
12
Q
Where is the shoulder joint?
A
Ventral end of 1st rib
13
Q
Where is the olecranon?
A
Below ventral end of 5th intercostal space
14
Q
What are the 2 parts of the vertebral arch?
A
Lamina and Pedicles
15
Q
What are all 13 of the vertebral foramen put together called? A few?
A
Spinal cord. Vertebral canal
16
Q
What are the foramen between the vertebrae called?
A
Intervertebral foramen
17
Q
What special name does T11 have?
A
Anticlinal vertebra
18
Q
What are the 2 layers of the vertebral disc called?
A
Anulus fibrosis and nucleus pulposus
19
Q
What ribs are part of the costal arch and which is the floating rib?
A
10-12.
13
20
Q
What nerves and arteries supply the thoracic wall muscles?
A
Intercostal arteries and intercostal nerves
21
Q
Where do arteries and nerves run in the intercostal space?
A
Caudal medial
22
Q
Which direction does muscles of expiration run?
A
Cranioventral
23
Q
What direction do muscles of inspiration run?
A
Caudoventralis
24
Q
What are the muscles of inspiration?
A
Scalenus
serrates dorsalis cranialis
external intercostal
rectus thoracis
25
What are the muscles of expiration?
Serrates dorsalis caudalis
Transfersus thoracis
Internal intercostal
26
What are the aortic cusps
Left semilunar cusp
Right semilunar cusp
Septal semilunar cusp
27
What are the cusps of the pulmonary valve
Right semilunar cusp
Left semilunar cusp
Intermediate semilunar cusp
28
What is the cardiac skeleton also known as?
Fibrous base
29
What are the borders to the thoracic inlet?
Bilateral: First rib
Ventrally: manubrian
Dorsally: first thoracic vertebrae
30
What 3 structures pass through the aortic hiatus?
Azygos vein
Aorta
Thoracic duct
31
What passes through the esophageal hiatus?
Esophagus
Vagal nerve trunks
32
What are the two components to the cardiovascular system?
Blood and lymph
33
What are the 3 layers of arteries and veins?
Tunica intima
Tunica media
Tunica adventitia
34
What is the main noteable function of the tunica intima?
It’s coagulation properties
35
What is the tunica media made of?
Smooth muscle
Extracellular matrix (elastin and ground substance)
36
What are the characteristics of elastic arteries?
Aorta
High pressure, high volume
Thick tunica media
Lots of layers of elastin fibers
37
What’s the major difference between muscular and elastic arteries
Elastic arteries are closer to the heart and contain a lot more elastin fibers
Muscular arteries contain mostly smooth muscle and a lot of it
38
What’s a continuous endothelium?
Continuous endothelium and basal lamina
39
What’s fenestrated endothelium?
Fenestrated endothelium but continuous basal lamina
40
What’s sinusoidal endothelium?
Fenestrated endothelium AND basal lamina
41
What are 2 major differences between veins and arteries?
Arteries have a much larger tunica media and veins have valves
42
What is lymph fluid plus fat droplets called?
Chyle
43
What layer of the heart are the valves a part of?
The endocardium
44
What are the differences between cardiac cells and skeletal muscle cells?
Branching
Prominent connective tissue
Central nuclei
Intercalated discs
Purkinje fibers
45
What are the 2 layers of the parietal pericardium
Serous: mesothelium
Fibrous: collagenous stroma
46
What are the 3 types of cardiac conduction cells?
Cardiomyocytes
Purkinje cells
Pacemaker cells (nodes)
47
What are the 2 types of action potentials?
Cardiomyocytes and Purkinje use Na for depolarization
Pacemaker cells use Ca for depolarization
48
What are the 5 phases of action potentials?
In Cardiomyocytes and Purkinje cells
0: depolarization Na enters
1: brief repolarization K exits
2: plateau Ca enters and balances K leaving
3: repolarization more K channels open
4: resting membrane potential
49
What makes pacemaker cells automatic?
Spontaneous phase 4 depolarization
50
What phases do pacemakers lack?
1 and 2 (brief depolarization and plateau)
51
What is the funny current of pacemaker cells?
What is phase 0 for pacemaker cells?
Na and K in
Slow Ca in
52
What is the funny current?
Occurs in pacemaker cells and it’s a slow drift of Na and K into the cell until Ca channels open at -50
53
What determines cell to cell conduction velocity?
How fast sodium enters the cell during depolarization (phase 0)
54
What are the types of calcium channels?
Voltage-gated: T-type (transient) and L-type (long-lasting)
Ligand Gated: epinephrine and norepinephrine
55
What channel determines the speed of repolarization?
Potassium (K) leaving
56
What does ERP mean?
Effective refractory period
Time before cell can be re stimulated
57
What slope is increased in sympathetic activity?
Slope of the funny current (the slow Na and K into the cell)
58
Explain excitation-contraction coupling
Stimulus causes a rush of Na to enter which allows L type Ca channel to let in a little Ca which binds Ryanodine receptor and causes a large rush of Ca from SR which binds tropomyosin and expresses actin, allowing myosin heads to swing and cause tension pulling Z band. Muscle relaxes and ATP drives Ca back into the SR through SERCa
59
What does hyperkalemia cause?
Sodium channels to become inactivated
60
What is the areolar tissue that attaches the muscles, ligaments, and bones to the underlying costal and diaphragmatic plurae?
Endothoracic fascia
61
What are the 2 pleural recesses?
Costodiaphragmatic recess
Costomediastinal recess
62
What is the cupula pleura?
Cranial part of parietal plura that extends outside of the thoracic inlet (left is larger)
63
What divides the dorsal and ventral mediastinum?
Divided by the roots of the lungs
64
What are the 3 layers of the pericardium?
Fibrous (outer layer)
Parietal serous (outer inner layer)
Visceral serous (inner inner layer also epicardium)
Mediastinal pleura on outside of this
65
What are the 2 ligaments that anchor apex of the heart?
Phrenicopericardial ligament
Sternopericardial ligament
66
Describe the relationship of the esophagus and trachea
Esophagus is left of trachea at thoracic inlet and dorsal after thoracic inlet
67
How many incomplete rings on the trachea are there?
35
68
What connects consecutive tracheal rings?
Annular ligaments of the trachea
69
Where is the tracheal bifurcation?
T4-T5
70
What is the crest inside of the trachea called?
Tracheal carina
71
What are the 4 surfaces of the lungs?
Costal
Diaphragmatic
Interlobar
Mediastinal
72
Where is the cardiac north located?
At 4th and 5th intercostal spaces (between cranial and middle lobes of right heart)
73
What are the borders of the triangular area of lung auscultation?
Cranial: triceps and Teres major mm @ 5th rib
Dorsal: back muscles, ribs 5-11
Basal border: caudoventral 6th rib at the costochondral junction to mid 8th rib, to dorsal 11th rib
74
What does the costocervical trunk branch into and what do they supply?
Deep cervical
Dorsal scapular
1-3 intercostal spaces
Muscles of base of neck
75
What are the 3 arteries that supply the thoracic wall?
Descending aorta
Internal thoracic
Costocervical trunk
76
What are the 2 veins of the heart?
Coronary sinus
Great cardiac vein (in paraconal interventricular groove and arises at apex!!)
77
What are the 4 lymph nodes of the thoracic cavity?
Tracheobronchial lymph nodes
Mediastinal lymph nodes
Sternal lymph nodes
Intercostal lymph nodes
78
Where does the thoracic duct switch to the left side?
Where does it empty?
At T5
Into left brachiocephalic vein
79
What is the opposite of the autonomic nervous system?
Somatic nervous system
80
What is the neurotransmitter of the parasympathetic and sympathetic divisions respectively?
Acetylcholine and norepinephrine
81
What are the 4 parasympathetic cranial nerves?
III: Oculomotor
VII: Facial
IX: glossopharyngeal
X: Vagus
82
Where are the intercostal nerves (thoracic spinal nerves) located?
Caudomedial to each rib
83
What allows for charge to spread throughout the heart simultaneously for regions?
Intercalated discs
84
What are the 2 phases of systole?
Isovolumetric constriction (ventricular pressure is lower than aortic)
Ejection (ventricular pressure is higher than aortic so aortic valve is open)
85
What two things are dependents of the strength of contraction?
Rate and extent of fiber shortening
86
Inotropy increases or decreases with calcium?
Increases
87
Inotropy increases or decreases with increases preload?
Increases
88
Inotropy increases or decreases with increased afterload?
Decreases
89
Inotropy increases or decreases with increasing heart rate?
Increases
90
What is the parasympathetic receptor for Cardiomyocytes?
What chemical does this receptor receive?
Muscarinic M2
Acetylcholine
91
What 3 things increase with increased sympathetic stimulation?
Increased rate of contraction
Increased peak force
Increased rate of relaxation
92
What is the definition of preload
Volume of blood in the ventricle at end of diastole
93
What is the definition of afterload?
Resistance left ventricle must overcome to circulate blood
94
What is Frank Starling Law?
Increased preload causes an increase in contractility within physiological limits
Think of that actin myosin overlap
95
What is the anrep effect
Chronic increase in preload causes decreased contractility vbut a very acute increase causes a short increase in contractility
96
What is the LaPlace Law?
(Pressure x ventricular radius)/(2 ventricular wall thickness) = afterload
97
What is the bowditch treppe effect?
Increased contractility with increased frequency (HR)
98
What is cardiac output equation?
CO=HR x stroke volume
99
Does systolic function = contractility?
NO!
Individual cell shortening = contractility
Chamber contraction = systolic function
100
What is lusitropy
Characterize rate and extent of fiber lengthening
101
What is the role of phosphlamben?
It inhibits SERCA which stops contraction
SNS increases SERCA and decreases phosphlambin’s effects so that the relaxation period occurs faster
102
Does diastolic function = lusitropy?
NO
cell lengthening = relaxation (lusitropy)
Chamber filling = diastolic function
103
What are the 4 phases of diastole?
Isovolumetric relaxation
Rapid filling
Slow filling
Atrial kick
104
What is diastolic compliance?
Compliance = stiffness = distensibility
Steeper curves = bad and less compliant
Increased compliance is better!
105
What happens to compliance and diastole as stiffness increases?
Decreased compliance and decreased diastolic function
106
What are the 2 major determinants of diastolic function and what are they influenced by?
Relaxation and stiffness (compliance)
Heart rate and preload
107
What is the left ventricle pressure range?
12-120
108
What is the right ventricle pressure range?
5-25
109
What is the aorta pressure range?
80-120
110
What is the pulmonary artery pressure range?
12-25
111
What is pulse pressure?
Difference in systolic and diastolic pressure
112
Which 2 sounds are the systolic sounds?
S1 and S2 (lub dub)
113
What are the diastolic sounds?
S3 and S4 (early ventricle filling and the atrial kick)
114
What are the ranges of pressures for the right atrium?
0-5
115
What are the normal pressures for the left atrium?
0-12
116
What is the most common disease place for dogs with a cough?
Tracheal
117
What is most common cause of cough with cats?
Bronchial
118
What is pallor and what is a cause?
Pale mucous membranes from anemia or vasoconstriction
119
What is a water hammer pulse?
A large difference between systolic and diastolic pressure
120
What is a cause of a higher heart rate than pulse palpation?
(Pulse deficit p) caused by arythmias
121
What is the hepatojugular reflex used for?
Test for right heart failure
122
What is weak arterial pulse also known as?
Pulses parvus
123
What is the bell of a stethoscope used well for.
To hear gallops (diastolic)
124
Do you use valve areas for cats?
No
125
What is a “click”
High pitched sound during systole associated with AV valve defernation and prolapse
126
What are murmurs characterized by?
Intensity, location, and timing
127
What are the 2 zones of the lower airways?
Conducting zone - trachea to terminal bronchial, no gas exchange
Respiratory zone - respiratory bronchial to alveolar structure - sit of gas exchange
128
What is the smallest tube that does not participate in gas exchange?
Terminal bronchioles
129
Describe bronchiole histology
Simple cuboidal
Club cells
No cartilage
130
What cell predominates in alveolar cells?
Club cells
131
What is the supporting tissue in the respiratory zone?
Elastic tissue
132
What are the alveoli cells and what do they do?
Alveolar type I: structural cells for gas exchange
Alveolar type II: Produce surfactant, divide to produce type I cells
133
Does the composition of gas matter for gas movement?
NO
134
What is the difference between bulk flow and diffusion
Bulk flow is the flow from high pressure to low pressure (independent of gas composition)
Diffusion is the random flow from high pressure to low pressure (dependent on gas composition)
135
Is gas exchange bulk flow or diffusion?
Diffusion
136
What is the equation for bulk flow (F)?
F=(Pb-Pa)/R
137
Can PAO2 be measured from PaO2?
What about PACO2 from PaCO2?
No
Yes
138
Describe difference between VdotA and VdotM
VdotA is volume of air entering alveolar per minute while VdotM is the amount of air entering the lungs per minute. VdotA matters more than VdotM because VdotA only takes the air reaching the respiratory zone into consideration.
139
What’s the best way to increase VdotA?
Deeper breaths to fill the alveolar space rather than hyperventilation which fills mostly only dead space
140
What are the 2 types of chemoreceptors for ventilation?
Peripheral in arteriole walls:
Central in medulla: function via CO2 and causes an increased tidal volume
141
What are the 2 peripheral chemoreceptors?
How are they signaled?
Carotid bodies: glossopharyngeal nerve
Aortic bodies: vagus
142
What plays a larger role in chemoreceptors? O2 or CO2?
CO2 because it is physiologically more beneficial
143
What is the purpose of the surfactants that are produced by the ATII?
Reduce the surface tension that help to reduce the CL (lung compliance)
144
What are the 3 determinants of lung compliance?
Elasticity
Surface tension
Ability of chest wall to inflate and deflate
145
What are the 3 determinants of airway resistance?
Geometry: length and branching angles
Air viscosity
Airway radius (1/r^4)
146
What are the 3 processes required for efficient gas exchange?
Alveolar ventilation
Perfusion of blood from systemic circulation
Perfusion of gases across the membrane
147
What is Henry’s law?
In equilibrium, partial pressure in gas and liquid phases are identical (allows for transfer of gases into liquid through alveolar surface)
148
What role does gas diffusion have on solubility?
High molecular weights cause gas to diffuse exponentially more
149
What is Fick’s Law?
Rate at which a gas flows across a membrane is dependent on
Surface area
Thickness of membrane
Diffusibility of gas (gamma)
Difference in partial pressure of gas
150
What supply the alveolar tissue with nutrients?
Bronchial arteries (pulmonary arteries bring deoxygenated blood)
151
What are the 3 starling forces?
Hydrostatic pressure
Oncotic pressure
Permeability of capillary endothelium
152
What zone is the heart at rest?
2
153
What is zone is the heart in during exercise?
3
154
What zone is an abnormal heart in?
1
155
What is hypoxia vasoconstriction?
Reduced airflow to alveoli results in lower blood flow to these areas
156
What is hypocapnic bronchoconstriction
When airways are exposed to gas with lower than normal PACO2 which redirects blood flow to better regions
157
Does O2 bound to Hb contribute to PaO2
NO
Only dissolved O2 in plasma does
158
What is the law of mass action?
Velocity of a reaction is proportional to the product of the concentration of the reactants
159
What are the 3 ways the body handles acids?
Respiratory - Ventilation: minutes to hours
Metabolic - Buffers
Metabolic - Renal: hours to days
160
What is the most important buffer?
Bicarbonate buffer
161
What are the 3 ways that CO2 can transport in the blood stream?
Dissolved
As bicarbonate
As carbinohemoglobin
162
What are the 3 measured values in blood
pH
PCO2
PO2
163
What are the 2 calculated measurements in blood?
HCO3 (bicarbonate)
Base excess
164
What are the normal values for pH, PaCO2, HCO3?
7.4, 40, 24
165
What is the threshold for acidemia and alkalemia?
7.35 and 7.45
166
What is positive base excess and what is negative base excess?
Negative: base acidosis
Positive: base alkolosis
BE DOES NOT CHANGE IN ACUTE RESPIRATORY DISTURBANCES
167
What are the metabolic interpretations of blood gas?
Base excess
PCO2
pH
168
What are the respiratory interpretations of blood gas?
PCO2
PO2
169
Which way does the primary disturbance go?
Goes in the direction of the pH!
170
BASE EXCESS DOES NOT CHANGE IN ACUTE RESPIRATORY DISTURBANCES
YES
171
What spinous processes make up the withers?
T2-T8
172
What are the 3 epaxial msucles from lateral to medial?
Longissimus, spinous system, multifidis
173
What is the epaxial muscle?
Longus colli
174
Where does trachea bifurcate in horse
4th to 6th
175
Where is cardiac notch of horse of left lobe
Between 3 and 6
176
Where is cardiac notch of right lung of horse?
Ribs 3 and 4
177
Where is the heart positioned in a horse?
Between intercostal spaces 2 and 6
178
What are the 3 branches of the costocervical trunk off the right subclavian?
Deep cervical
Dorsal scapular
Supreme intercostal
179
What are the 3 branches of the descending aorta?
Dorsal intercostal
Ventral intercostal
Bronchioesophageal
180
Should you take a radiograph on expiration or inspiration?
Inspiration
181
Where do you start measurement with vertebral heart scale?
At the cranial border of the 4th rib
182
What’s about the average vertebral heart size for dogs and cats respectively?
9.7 and 7.5
183
Are arrhythmias common in dogs? What about cats?
Yes
No!
