cardiovascular

Question 1

contrast and compare skeletal muscle cell vs contractile myocardial cell

Answer 1

similarity: striated,has mitochondria, requires C2+ to contract
sksletal are cylindrical cells, motor neuron AP
contractile are branched and electrically connected

Question 2

pathway that AP travel throughout the heart

Answer 2

1. sinotrial node depol
2. atrial muscle
3. atriovencular node (aV)
4. bundle of His
5. Bundle branches 9L & R)
6. Purkinje fibre
7. ventricular muscle

Question 3

resting heart rate

Answer 3

70 beats / min

Question 4

how to calculate max heart rate

Answer 4

220-age

Question 5

how PSNS change heart rate

Answer 5

Ach binding its recep will:
< K+ permeability (more K+ leaves)
bt > Na+ ^& Ca2+’s (less them leaving)

Question 6

how SNS affect heart rate

Answer 6

NE (norepinephrine) bidns to receptor will:
< Na+ & Ca2+ permeability
=> release epinephrine to heart

Question 7

how heart rate goes up (100 -> 130) and down (100 -> 70) if one is on a run

Answer 7

• controlled by SA node, intrinsic rate

RUN: 100 beats/min -> sympathetic activates -> beats 130
REST: 100 beats/min -> parasympathetic ativates -> 70

Question 8

describe 1st phases in the cardiac cycle

Answer 8

atrial systole
ECG: [ wave occurs before
atrial pressure oincreases
valves open
ventricular vol increase

Question 9

describe 2nd phase in cardiac cycle \

Answer 9

early ventricular systole (isovlumetric)
- QRS wave before
ventricular p increases (exceed atrial [P bt lower than oartic)
all valves closed
no vol change

Question 10

describe 3rd phase in cardiac cycle

Answer 10

ventricular systole (rapid ejection period)
- ventroicular P < (higher than aortic and atrial)
aortic valves open
ventriuclar vol >

Question 11

describe 4th phase in cardiac cycle

Answer 11

early ventriuclar diastole (isovolumetric)
- ECG: T waves before
- ventricular P decrease
- all valves closed, no vol change

Question 12

5th phase in cardiac cycle

Answer 12

late ventricular diastole
ventricular P decrease
AV valves open
ventricular vol increase

Question 13

how PSNS & SNS affecgt stroke volume

Answer 13

PSNS release ACh to innervate cardic contractile cells
=> >Cà+ permeability which > weaker contraction & less SO

SNS: via the release of NE / epinephrine to innercate vemtroci;ar ,isc;e ce;;s
=more Ca comes in whihc stronger contraction & more SO

Question 14

describe the 3 layers in arteries and veins

Answer 14

tunica externa = of fibrous connective tissue
-> tunica media = smooth muscle and eleastic fibres
-> tunic interna endothelial cells

Question 15

3 differences btw aorta + arteries vs arterioles vs capillarie vs venules

Answer 15

1/ large diameter 2/ small diameter 3/ smallest
1/ thin walls to 2/ thick walls 3/ very thin walls
1/ has very high BP 2/ drop in bP 3/low BP & lsmall dro in bp

Question 16

net filtration pressure of cardiovascular

Answer 16

Kf [(Pc + TTIF) + [(Pif + TTc)

Question 17

why you will pass out when you hyperventilate?

Answer 17

via medtabolic theory, more CO2 removed from blood => less PCO2 in bloods
blood vesel contract => less blood flower to brain -> pass out

Question 18

compare SNS vs PSNS’s on neural contraol mechanism

Answer 18

PSNS: innervates SA AV nodes
=? decrease HR
SNS: innvervates SA & AV node and fentricular muscle
-> increase HR SV vasocontriction

Question 19

what is MAP and how to find it?

Answer 19

diastolic P + 1/3(systolic -diastolic P)

Question 20

calculate cardiac output

Answer 20

= heart rate (bpm) x Stroke Volume (mL)

Question 21

group these agents of humoral regulation into 2 groups: angiotensin II, ANP, ADH, epinephrine

Answer 21

agents involved in vasocontriction:
- epinephrine / angiotensin II / ADH
agents involved in vasodilation:
- epinephrine / ANP

Question 22

why is gap junction so important in the myocardial cells?

Answer 22

to allow ions and AP to read so whole cell can contract

Question 23

desribe a typical SA nodal action potential

Answer 23

pacemaker potential: membrane slowly and spontaneously depol to threshold (-60 to -40)
-> aP triggers

depol: Ca VG channels open for influx of Ca
repoil; K+ VG channels and k+ leaves -> go back to RMP

Question 24

_________ myocardial cells can _____ generate _____. It is divided into 2 types: ____ & _____ (which has minimal actin & __-)

Answer 24

self-excitable / spontaneously / AP / contracttile heart cells / nodal & conducting cells/ myosin

Question 25

compare effect of PSNS and SNS on stroke volume

Answer 25

via release of ACh / release of NE & epinephrine
decrease Ca+ permea / more Ca+ enters
weaker contraction so less SO / stronger contraction so higher SO

Question 26

if you have an increased EDV, what is the effect?

Answer 26

< in EDV = < in preloaed
requires larger stretch of ventricular contractile cells
stronger contraction of these cells upon systole
more blood ejected from heart
higher SO =higher cardiac output

Question 27

descrine the relationship btw blood flow, pressure and resistance in a sentence and a calculation

Answer 27

blood flows down a pressure gradient bt resistance decrease flow

blood flow = P gradient / 1/r^4 (resistanc)

Question 28

why is blood velocity the lowest in capill?>

Answer 28

since blood velocity is inversely proportional to total cross-sectional area, and capill requires the largest TCA blood move slowest here

Question 29

which Starling forces promotes filtration? reabsorption?

Answer 29

filtration:
- Pc
- Pif when negative
- TT if

reabsorption:
- TTc
- Pif when positive

Question 30

vasocontriction: ___ flow, ___ P VS vasodilation: ____

Question 31

overall, PSNS __ HR, SO, and cause ____
overall SNS ____ HR, SO and cause ____

Answer 31

• decrease/ vasodilation
• increase / vasocontriction