Exam 2- Cardio

Question 1

rate at which blood is pumped from either ventricle

Answer 1

cardiac output/afterload

Question 2

rate at which blood is returned to the atria

Answer 2

venous return/preload

Question 3

blood vessels with thick walls, elastic tissue, highest pressure, and stressed volume

Answer 3

arteries

Question 4

site of highest resistance to blood flow

Answer 4

arterioles

Question 5

single layer of endothelial cells that serve as site of exchange of nutrients, gases, water, and solutes between blood and tissues

Answer 5

capillaries

Question 6

contain unstressed volume, have large capacitance

Answer 6

veins/venules

Question 7

velocity is directly proportional to (blank); inversely proportional to (blank)

Answer 7

blood flow; cross sectional area

Question 8

blood flow is directly proportional to (blank) and inversely proportional to (blank)

Answer 8

pressure gradient; resistance

Question 9

resistance depends on

Answer 9

diameter and blood viscosity

Question 10

resistance directly proportional to (2 things)

Answer 10

velocity and vessel length

Question 11

formula for series resistance

Answer 11

Rtotal = R1 + R2 + R3….

Question 12

formula for parallel series

Answer 12

1/ Rtotal = (1/R1) +(1/R2) + (1/R3)…….

Question 13

streamlined parabolic profile of velocity within a blood vessel in which velocity is greatest in the center and 0 at the walls

Answer 13

laminar flow

Question 14

disrupted flow that occurs at valves or site of blood clot or in vessels of high velocity

Answer 14

turbulent flow

Question 15

predicts if flow will be laminar or turbulent; greater number = greater tendency for turbulence

Answer 15

Reynold’s Number

Question 16

distensibility of blood vessels, inversely relate to elasticity

Answer 16

compliance

Question 17

pressure in the artery during ventricular relaxation; lowest arterial pressure

Answer 17

diastolic pressure

Question 18

pressure in the artery during ventricular contraction; highest arterial pressure

Answer 18

systolic pressure

Question 19

difference between systolic and diastolic pressure, relates to stroke volume

Answer 19

pulse pressure

Question 20

average pressure in a complete cardiac cycle

Answer 20

mean arterial pressure

Question 21

causes an increase in systolic pressure, ouse pressure, and mean arterial pressure

Answer 21

arteriosclerosis

Question 22

causes a decrease in systolic pressure, pulse pressure, and mean arterial pressure

Answer 22

aortic stenosis

Question 23

incompetent aortic valve disrupts blood flow into the aorta, resulting in retrograde flow

Answer 23

aortic regurgitation

Question 24

where are conducting cells found

Answer 24

SA node, atrial internodal tracts, AV node, bundle of His, purkinje fibers

Question 25

normal sinus rhythm range depends on

Answer 25

action potential must originate in SA node SA node impulses must occur regularly at 60-100 impulses/min activation of the myocardium must occur in the correct timing and delays

Question 26

Phase 0 of cardiac action potential

Answer 26

rapid depolarization caused by transient increase in Na conduction

Question 27

Phase 1 of cardiac action potential

Answer 27

brief period of repolarization, net outward current | inactivation gates on Na channels close, outward current of K

Question 28

Phase 2 of cardiac action potential

Answer 28

"plateau" - long period of stable depolarized membrane potential, no net current flow across membrane inward Ca current (slow) balanced by outward K current

Question 29

Phase 3 of cardiac action potential

Answer 29

repolarization; outward currents > inward currents

Question 30

Phase 4 of cardiac action potential

Answer 30

resting membrane potential/electrical diastole membrane potential stable again inward and outward currents are equal (inward Na and Ca balance out outward K)

Question 31

Phase 0 of SA node action potential

Answer 31

slow upstroke caused by inward Ca current

Question 32

Phase 3 of SA node action potential

Answer 32

repolarization; increase in outward K current

Question 33

Phase 4 of SA node action potential

Answer 33

longest part of SA action potential slow upstroke due to inward Na current conducts Na, K and Ca inward Na turned on by repolarization of preceding AP accounts for automaticity of SA nodal cells, rate of phase 4 determines heart rate

Question 34

speed at which APs are propagated in the tissue | slowest in Av node to allow for ventricular filling; fastest in Purkinje fibers

Answer 34

conduction velocity

Question 35

prevents conduction directly from atria to ventricles

Answer 35

antrioventricular ring

Question 36

rate of conduction depends on (2 things)

Answer 36

size of inward current (# of ion channels) | more negative threshold

Question 37

ability of cells to initiate an AP in response to inward depolarizing current; reflects recovery of channels that carry inward current during upstroke

Answer 37

excitability

Question 38

period during which another AP cannot be elicited regardless of current; begins with upstroke and ends after plateau

Answer 38

absolute refractory period

Question 39

period during which a generated AP cannot be conducted, Na+ channels begin to recover; inward current not enough to conduct to next site

Answer 39

effective refractory period

Question 40

AP can be elicited if greater than usual current; occurs immediately after ARP when repolarization is almost complete

Answer 40

relative refractory period

Question 41

period during which cell is more excitable than normal

Answer 41

supranormal period

Question 42

chronotropic effects

Answer 42

effects of ANS on heart rate via SA node positive=increase HR negative = decrease HR

Question 43

dromotropic effects

Answer 43

effects of ANS on conduction velocity via AV node positive = increase conduction (symp B1) negative = decrease conduction (parasymp)

Question 44

p wave of EKG represents

Answer 44

atrial depolarization

Question 45

PR interval of EKG

Answer 45

initial ventricular depolarization

Question 46

QRS complex of EKG

Answer 46

ventricular depolarization

Question 47

T wave

Answer 47

ventricular repolarization

Question 48

QT interval

Answer 48

entire period of depolarization and repolarization of ventricles

Question 49

ST segment

Answer 49

ventricular repolarization

Question 50

maintain cell - cell cohesion, have gap junctions for cardiac muscle synctium

Answer 50

intercalated disk

Question 51

ability of myocardial cells to develop force at a given muscle length

Answer 51

ionotropism

Question 52

amount of Ca released from SR depends on... (2 things)

Answer 52

size of inward Ca current during plateau | amount of Ca previously stored in SR for release

Question 53

contractility depends most on

Answer 53

intracellular Ca concentration

Question 54

positive ionotropic effect

Answer 54

increase contractility, increase rate of tension development/peak tension, increase rate of relaxation mediated by B1 receptors

Question 55

positive staircase effect

Answer 55

as intracellular Ca increases, HR increases and force of contraction increases in stepwise fashion

Question 56

post extrasystolic potentiation

Answer 56

during an extra beat further release of Ca causes extra beat to have stronger force of contraction

Question 57

used to treat CHF, inhibit Na-K ATPase to increase intracellular Na and Ca

Answer 57

positive ionotropic agents such as Digoxin

Question 58

equivalent to end-diastolic volume; related to right atrial pressure

Answer 58

preload

Question 59

volume of blood ejected by a ventricle on each beat

Answer 59

stroke volume

Question 60

fraction of the end diastolic volume in each stroke volume, measures ventricular efficiency

Answer 60

ejection fraction