Physiology

Question 1

Cardiac output equation

Answer 1

CO=SV x HR

Question 2

Fick principle

Answer 2

CO=rate of O2 consumption/ arterial O2 content - venous O2 content

Question 3

Mean Arterial Pressure (MAP) equation

Answer 3

MAP = CO x TPR (total peripheral resistance)

MAP= 2/3 diastolic pressure + 1/3 systolic pressure

Question 4

pulse pressure equation

Answer 4

PP=systolic pressure -diastolic pressure

Question 5

pulse pressure is proportion to

Answer 5

Stroke Volume

Question 6

pulse pressure is inversely proportional to

Answer 6

arterial compliance

Question 7

what are examples of pulse pressure being proportional to SV

Answer 7

increase PP in hyperthyroidism, aortic regard, aortic stiffening (isolated systolic hypertension in elderly), obstructive sleep apnea (increase sympathetic tone), exercise (transient)

Question 8

what are examples of pulse pressure being inversely proportional to aortic compliance

Answer 8

decrease PP in aortic stenosis,, cardiogenic shock, cardiac tamponade, advanced heart failure

Question 9

Stroke volume equation

Answer 9

SV = EDV - ESV

Question 10

how is CO maintained in the early stages of exercise?

Answer 10

by increase in HR and increase in SV

Question 11

how is CO maintained in the late stage of exercise?

Answer 11

increase in HR ONLY (SV plateaus)

Question 12

Diastole is preferentially shortened with

Answer 12

increase HR; less filling time –> decrease CO (ex: V tach)

Question 13

stroke volume is affected by what variables

Answer 13

Contractility, after load and preload

Question 14

an increase in SV is seen with:

Answer 14

an increase in contractility and preload, but a decrease in afterload

Question 15

what are examples of increased contractility

Answer 15

exercise pregnancy anxiety

Question 16

a failing heart has an increase or decreased SV

Answer 16

decreased

Question 17

Contractility (and SV) increases with:

Answer 17

Catecholamines, increase intracellular Ca2+, decrease extracellular Na+, digitalis

Question 18

contractility (and SV) decrease with:

Answer 18

B1 blockade, HF with systolic dysfunction, acidosis, hypoxia/hypercapnia, Non-dihydropyridine Ca2+ channel blockers

Question 19

and increase in myocardial oxygen demand is increased by:

Answer 19

increase in contractility, increase in after load, increase in hr, increase in diameter of ventricle (increase in wall tension)

Question 20

what law does wall tension follow?

Answer 20

Laplaces law

Question 21

What is laplace’s law

Answer 21

wall tension: Pressure x Radius / 2 x thickness

Question 22

preload is approximated by what variable?

Answer 22

ventricular EDV

Question 23

after load is approximated by what variable?

Answer 23

MAP

Question 24

preload depends on:

Answer 24

venous tone and circulating blood volume

Question 25

what drugs will decrease preload?

Answer 25

Venodilators (ex: nitroglycerin)

Question 26

what drugs will decrease after load?

Answer 26

Vasodilators (ex: hydralazine)

Question 27

if you have an increase in after load you will see and increase in what else?

Answer 27

increase after load--> increase pressure --> increase wall tension

Question 28

how does the LV compensate for an increase after load

Answer 28

lv compensates for an increase afterlaod by thickening (hypertrophy) in order to decrease wall tension

Question 29

what drugs will decrease both after load and preload?

Answer 29

ACEi and ARBs

Question 30

if you have chronic hypertension (increase MAP)

Answer 30

increase LV hypertrophy

Question 31

Ejection Fraction

Answer 31

EF= SV/EDV= EDV-ESV/EDV

Question 32

what is a normal ejection fraction?

Answer 32

>55%

Question 33

Left ventricular EF is an index of

Answer 33

ventricular contractility

Question 34

does ejection fraction increase or decrease in systolic HF?

Answer 34

decreases

Question 35

does ejection fraction increase or decrease in diastolic HF?

Answer 35

normal

Question 36

Force of contraction is proportional to end diastolic length of cardiac muscle fiber (preload)

Answer 36

True

Question 37

how can you increase contractility?

Answer 37

digoxin, catecholamines

Question 38

how can you decrease contractility?

Answer 38

mi, b blockers, nondihydropyrdinine Ca channel blockers, dilate cardiomyopathy

Question 39

resistance presssure flow equation

Answer 39

change in P = Q x R

Question 40

Ohm's law

Answer 40

change in V = IR

Question 41

volumteric flow rate equation

Answer 41

change in Q= V (flow velocity) x A (cross-sectional area)

Question 42

resistance equation

Answer 42

change in P / Q = 8n x Length / (pi)r^4

Question 43

Total resistance of vessels in series

Answer 43

TR= R1 +R2 +R3...

Question 44

Total resistance of vessels in parallel

Answer 44

1/TR=1/R1+1/R2+1/R3....

Question 45

viscosity depends on

Answer 45

hematocrit

Question 46

when do you see an increase in viscosity

Answer 46

hyperproteinemic states (multiple myeloma) or polycythemia

Question 47

when do you see a decrease in viscosity?

Answer 47

anemia

Question 48

Capillaries have the highest total cross-sectional area and lowest flow velocity

Answer 48

TRUE

Question 49

what changes will you see in TPR and CO when removing an organ, for example in nephrectomy

Answer 49

increase in TPR, decrease in CO

Question 50

who accounts for most of TPR

Answer 50

arterioles

Question 51

who provides most of blood storage capacity?

Answer 51

veins

Question 52

who provides most of blood storage capacity?

Answer 52

veins

Question 53

isometric contraction

Answer 53

period between mitral valve closing and aortic valve opening period of highest O2 consumption

Question 54

systolic ejection

Answer 54

period between aortic valve opening and closing

Question 55

isovolumetric relaxation

Answer 55

period between aortic valve closing and mitral valve opening

Question 56

rapid filling

Answer 56

period just after mitral valve opening

Question 57

reduced filling

Answer 57

period just before mitral valve closing

Question 58

S1

Answer 58

mitral and tricuspid valve closure loudest at mitral area

Question 59

S2

Answer 59

aortic and pulmonary valve closure loudest at left upper sternal border

Question 60

S3

Answer 60

in early diastole during rapid ventricular filling phase

Question 61

Which S sound is associated with increase filling pressured more common in dilated ventricles?

Answer 61

S3

Question 62

S4

Answer 62

in late diastole ("atrial kick"

Question 63

which S sound is best heard at apex with patient in left lateral decubitus position?

Answer 63

S4

Question 64

Which S sound is associated with a high atrial pressure, ventricular hypertrophy ( left atrium must push against LV wall)?

Answer 64

S4

Question 65

a wave

Answer 65

atrial contraction

Question 66

when do you see an absent a wave?

Answer 66

afib

Question 67

c wave

Answer 67

RV contraction (closed tricuspid valve bulging into atrium)

Question 68

x descent

Answer 68

atrial relaxation and downward displacement of closed tricuspid valve during ventricular contraction

Question 69

when is X descent absent

Answer 69

in tricuspid regurg

Question 70

v wave

Answer 70

increase right atrial pressure due to filling against closed tricuspid valve

Question 71

y descent

Answer 71

RA emptying in RV

Question 72

R to L shunt description

Answer 72

early cyanosis; "blue babies", diagnosed prenatally or immediately after birth usually require surgery/correction and/or maintenance of a PDA

Question 73

examples of a R to L shunt

Answer 73

THE 5 T's: 1. Truncus Arteriosus 2. Transposition 3. Tricupsid Atresia 4. Tetralogy of Fallot 5. TAPVR

Question 74

Persistent Truncus Arteriosus

Answer 74

failure of the Truncus Arterioles to divide into Ascending aorta and pulmonary trunk due to failure of Aorticopulmonary septum to form most puts have accompanying VSD

Question 75

D-Transposition of great vessels

Answer 75

Due to failure of the aorticopulmonary septum to spiral, causing the Aorta to leave from the Right ventricle and the Pulmonary trunk to leave from the left ventricle, in turn this causes a separationg of the pulmonary and systemic circulations this is not compatible with life unless a shunt is created to allow the mixing of blood (ex: VSD, patent foramen ovale or PDA) without surgical intervention most infants die within a few months of life!

Question 76

Tricuspid atresia

Answer 76

absence of a tricuspid valve and hypoplastic RV requires both ASD and VSD for survival!

Question 77

Tetralogy of fallot

Answer 77

caused by anterosuperior displacement of the infundibular septum

Question 78

which congenital heart disease is the most common cause of early childhood cyanosis?

Answer 78

TOF

Question 79

what are the 4 defects seen in TOF?

Answer 79

PROV 1. Pulmonary infundibular stenosis (most important determinant factor for diagnosis) 2. Right ventircualr hypertrophy- boot shaped heart on CXR 3. Overriding aorta 4. VSD

Question 80

what causes the early cyanotic get spells and RVH in TOF?

Answer 80

pulmonary stenosis forces R to L flow across VSD

Question 81

What improves cyanosis in TOF?

Answer 81

squatting

Question 82

how does squatting improve cyanosis in TOF?

Answer 82

increase in SVR , decrease in R to L shunt†

Question 83

how does squatting improve cyanosis in TOF?

Answer 83

increase in SVR , decrease in R to L shunt

Question 84

how does squatting improve cyanosis in TOF?

Answer 84

increase in SVR , decrease in R to L shunt

Question 85

TAPVR

Answer 85

Pulmonary veins drain into right heart circulation (SVC, coronary sinus, etc) associated with ASD and sometimes PDA to allow for R to L shunting to maintain CO