cardiac

Question 1

what is the equation for flow

Answer 1

chnage in pressure/ R (resistance)

Question 2

_____ opposes flow

Answer 2

resistance

Question 3

flow follows pressure gradient which means it goes from where to where

Answer 3

left ventricle –> right atrium
right ventricle —> left atrium

Question 4

hydrostatic pressure decreases due to

Answer 4

friction

Question 5

forward or driving pressure is strong in ______ contraction

Answer 5

ventricular

Question 6

flow is proportional to change in _____

Answer 6

pressure

Question 7

what factors affect resistance

Answer 7

vasoconstriction or dilation; blood viscosity (directly proportional) ; vessel length (directly proportional; longer vessel, more resistance)

Question 8

pressure generated by ventricular contraction

Answer 8

mean arterial pressure

Question 9

CO =

Answer 9

cardiac ouput; volume per time

Question 10

____ maintain pressure during ventricular relaxation

Answer 10

arteries

Question 11

MAP = ____ X ___

Answer 11

CO X R

Question 12

what system innervates entire heart (using NE and E)

Answer 12

sympathetic

Question 13

parasympathetic innervates _____ (primarily the atria)

Answer 13

cranial nerve (uses ACH)

Question 14

pacemakers nodal tissues and conduction fibers; generate and conduct action potentials

Answer 14

autorhythmic cells

Question 15

what two channels are responsible for excitation contraction coupling in T-tubules

Answer 15

voltage gated Na+ channels and L type Ca2+ channels

Question 16

the sarcoplasmic reticulum of the cardiac muscle has

Answer 16

ryanodine receptors and Ca2+ release

Question 17

the sarcolemma has two ATPase pumps for relaxation; what are they

Answer 17

Na/ K (3 Na out; 2 K in)
Ca/ ATPase
also a Na+ and Ca2+ exchanger (NCX)

Question 18

what two factors impact cardiac contractility

Answer 18

force developed is proportional to # of active crossbridges
sarcomere length of onset of contraction

Question 19

the length-tension relationship ( increased length; increased force)

Answer 19

frank-starling law of the heart

Question 20

rapid depolarization of the ventricular myofibers is due to

Answer 20

voltage gated Na channels open

Question 21

the plateau phase has what voltage gated channels

Answer 21

L -type Ca 2+ channels (K+ are closed) slow K+ are open

Question 22

the ___ period in a cardiac muscle fiber lasts almost as long as the entire muscle twitch

Answer 22

refractory

Question 23

unstable resting membrane potential uses what channels? Which channel has greater movement

Answer 23

Na+ and K+ channels; Na+ movement is larger

Question 24

sodium channels being inactive causes

Answer 24

absolute refractory period

Question 25

Repolarization is quickly interrupted as voltage-gated L-type calcium channels open, increasing calcium permeability and bringing positively charged calcium ions into the cell. Why is this unique?

Answer 25

Calcium has a large role in initiating AP

Question 26

Phase 4: The trace begins with a slow, incremental depolarization. Phase 0: Incremental depolarization is followed by a rapid depolarization when the threshold is reached. Phase 3: There is a rapid repolarization and then the incremental depolarization (Phase 4) begins again and the cycle repeats.

Answer 26

phases of pacemaker AP

Question 27

____ = pacemaker; 90-100 bpm (internodal pathway); communicate with atrial contractile cells

Answer 27

SA node

Question 28

does 25-40 bpm; transmit signals across fibrous skeleton

Answer 28

AV node

Question 29

contractile cells in the apex of the heart; help with direction of contraction

Answer 29

small purkinje fibers

Question 30

make up the atrioventricular bundle and right and left bundle branches

Answer 30

purkinje fibers

Question 31

right arm to left arm

Answer 31

lead I

Question 32

right arm to left leg

Answer 32

lead II

Question 33

left arm to left leg

Answer 33

lead III

Question 34

which lead most closely follows electrical axis of the heart

Question 35

current of ECG moves from

Answer 35

negative to positive

Question 36

atrial depolarization

Answer 36

P wave

Question 37

ventricular depolarization & atrial repolarization

Answer 37

QRS complex

Question 38

ventricular repolarization

Answer 38

T wave

Question 39

____ events precede ___ events

Answer 39

electrical; mechanical

Question 40

systole = ____ and ____

Answer 40

contraction and emptying

Question 41

valves from atrium to ventricle

Answer 41

atrioventricular

Question 42

when atrial pressure is greater the ventricular pressure the AV valves ___

Answer 42

open (ventricles relax)

Question 43

ventricles to great artery

Answer 43

semilunar valves

Question 44

as the ventricles contract the pressure in the ventricles exceeds pressure in the arteries; what valves are open?

Answer 44

semilunar

Question 45

the final filling (20%) of the ventricles gives what sound

Answer 45

S4

Question 46

during atrial depolarization and systole, the atria are _____ and _____

Answer 46

contracting and emptyinh

Question 47

during ventricular depolarization and systole, the ventricles are in

Answer 47

isovolumetric contraction

Question 48

the first heart sound S1 happens when AV valves are

Answer 48

closed

Question 49

during early ventricular diastole the ventricles are in

Answer 49

isovolumetric relaxation

Question 50

the second S2 sound happens when SL valves are

Answer 50

closed

Question 51

passive filling of ventricles is represented by what heart sound

Answer 51

S3

Question 52

volume of blood ejected by the ventricular system

Answer 52

stroke volume

Question 53

volume of blood at the end of ventricular diastole

Answer 53

end diastolic volume

Question 54

SV = ?

Answer 54

EDV-ESV

Question 55

CO (cardiac output) =

Answer 55

HR x SV

Question 56

the ____ is in charge of tonic control of the SA rate and HR

Answer 56

parasympathetic

Question 57

three factors for regulation of stroke volume

Answer 57

length, sympathetic input to ventricles , afterload

Question 58

ejection fraction (EF) = SV/EDV

Question 59

the ____ is what you have to work against in aorta

Answer 59

afterload

Question 60

rapid but regular SA rate and atrial contraction but relatively normal ventricular contractions

Answer 60

atrial flutter