CV phys and histo

Question 1

isovolumic contraction occurs from ____ to _____

Answer 1

closing of mitral valve to opening of aortic

Question 2

isovolumic contraction: pressure changes

Answer 2

atrial and ventricular pressure increase
aortic pressure deceases

Question 3

neutrophil functions

Answer 3

phagocytose bacteria and damaged tissue

Question 4

eosinophil functions

Answer 4

respond to parasitic infections, bronchial asthma, phagocytose antigen-antibody complexes

Question 5

aortic stenosis

Answer 5

systolic murmur
narrowing of aortic valve
heard @ upper left

Question 6

mitral regurgitation

Answer 6

systolic murmur
incompetent valve
heard @ apex

Question 7

cardiac myocytes: functional characteristics

Answer 7

gap junctions, functional syncytium
don’t fatigue
automaticity, rhythmicity
no spatial summation or tetanic contraction = long AP
high oxidative capacity

Question 8

cardiac muscle AP: initiation steps

Answer 8

1. SA node sends impulse to cardiomyocytes
2. depolarize, send cardiac AP
3. AP triggers Ca2+ influx via DHAP, RYR
4. Triggers Ca2+ induced Ca2+ release
5. Ca2+ binds troponin C, changes conformation

Question 9

afterload: effect on stroke volume

Answer 9

higher afterload = lower stroke volume

Question 10

positive inotropes: examples

Answer 10

catecholamines
angtiotensin II
digoxin

Question 11

negative inotropes: examples

Answer 11

beta-blockers
calcium channel blockers

Question 12

sympathetic NS: effect on contractility

Answer 12

activates beta-adrenergic receptors on cardiomyocytes
- increased cAMP and PKA activation
- phosphorylation of L-type of RYR: Ca2+ influx
- troponin I phosphorylation: Ca2+ dissociation, relaxation
- PLN phosphorylation: quicker relaxation by increased SERCA activity and more Ca2+ in SR

Question 13

treppe effect: stroke volume and HR

Answer 13

tachycardia: HR speeds up, stroke volume increases until steady
bradycardia: HR slows, stroke volume decreases until normal

Question 14

pressure-volume loop: phase 1

Answer 14

mitral valve opens, ventricular filling. passive tension.
ESV

Question 15

pressure-volume loop: phase 2

Answer 15

diastole, mitral valve closes as pressure drops. isovolumic contraction.
EDV

Question 16

fast-response AP steps

Answer 16

0. Na+ channels open, depolarize
1. Na+ channels inactivate, K+ channels open (efflux)
2. Plateau, L-type and RYR open, Ca2+ influx = K+ efflux
3. L-type Ca2+ close, K+ current increases
   - end of phase 3, during hyperpolarization: HCN channels open, create inward depolarizing current for SA node
4. repolarization

Question 17

pulse pressure equation

Answer 17

SBP-DBP

Question 18

MAP equation

Answer 18

DBP + PP3

Question 19

basophil function

Answer 19

granules with heparin, histamine
important in chronic inflammation, acute hypersensitivity, viral infections

Question 20

lymphocyte function

Answer 20

circulate as primary cell of immune system

Question 21

monocyte function

Answer 21

differentiate into macrophages, microglia, osteoclasts for phagocytosis