Cardiovascular Physiology Heart

Front 1

Define cardiac output

Back 1

stroke volume x heart rate; rate of O2 consumption/(arterial O2 content - venous O2 content)

Front 2

Define mean arterial pressure

Back 2

cardiac output x total peripheral resistance; 2/3 diastolic pressure + 1/3 systolic pressure

Front 3

Define pulse pressure

Back 3

systolic pressure - diastolic pressure; proportional to stroke volume

Front 4

Define stroke volume

Back 4

CO/HR; EDV-ESV

Front 5

Define preload

Back 5

ventricular EDV

Front 6

Define afterload

Back 6

MAP (proportional to peripheral resistance)

Front 7

Define ejection fraction. What is normal?

Back 7

index of ventricular contractility; SV/EDV; (EDV-ESV)/EDV; > or = 55%

Front 8

Define change in pressure

Back 8

flow x resistance

Front 9

Define resistance

Back 9

(8n (viscosity) x length)/ (pi x r^4)

Front 10

Define capillary pressure

Back 10

pushes fluid out of capillary

Front 11

Define interstial fluid pressure

Back 11

pushes fluid into capillary

Front 12

Define plasma colloid osmotic pressure

Back 12

pull fluid into cavity

Front 13

Define interstitial fluid colloid osmotic pressure

Back 13

pulls fluid out of capillary

Front 14

Define net filtration pressure

Back 14

(capillary pressure - interstitial fluid pressure) - (plasma colloid pressure - interestial fluid colloid osmotic pressure)

Front 15

Define net fluid flow

Back 15

net filtration x filtration constant

Front 16

Stroke volume is increased with

Back 16

increased contractility, decreased afterload, increased preload; anxiety, exercise, pregnancy

Front 17

Contractility and stroke volume increases with

Back 17

Catecholamines, increased intracellular calcium, decreased extracellular sodium, digitalis

Front 18

Contractility and stroke volume decrease with

Back 18

Beta1 blockade, heart failure, acidosis, hypoxia/hypercapnea, non-dihydropyridine Ca2+ channel blockers

Front 19

Myocardial O2 demand increases with

Back 19

Increased afterload, increased contractility, increased heart rate, increased heart size, increased wall tension

Front 20

What is the effect of exercise on cardiac output

Back 20

CO initially increases because of an increase in stroke volume. After prolonged exercise, CO increases because of an increased heart rate.

Front 21

How can you increase preload?

Back 21

Slight increases with exercise, increased blood volume, sympathetics

Front 22

List the phases of left ventricular contraction

Back 22

1. Isovolumetric contraction; 2. Systolic ejection; 3. Isovolumetric relaxation; 4. Rapid filing; 5. Reduced filling

Front 23

Which phase of ventricular contraction has the highest rate of O2 consumption?

Back 23

Isovolumetric contraction

Front 24

What is responsible for resistance in the cardiovascular system?

Back 24

Arterioles = most of total peripheral resistance

Front 25

What pathology increases viscosity?

Back 25

Polycythemia, Hyperproteinemic states (eg multiple myeloma), Hereditary spherocytosis

Front 26

What causes edema?

Back 26

1. increased capillary pressure (heart failure); 2. decreased plasma proteins (nephrotic syndrome, liver failure); 3. increased capillary permeability (toxins, infections, burns); 4. interstitial fluid coloid osmotic pressure (lymphatic blockage)

Front 27

Define 'a' wave

Back 27

JVP: Atrial contraction

Front 28

Define 'c' wave

Back 28

JVP: RV contraction

Front 29

Define 'v' wave

Back 29

JVP: Increased atrial pressure due to filling against closed tricuspid valve

Front 30

List the characteristics of cardiac myocyte cells

Back 30

Calcium-induced calcium release, plateau due to Ca2+ influx, automaticity, gap junctions creating electric coupling between cardiac myocytes