cardiovascular phys quiz 1

bulk movement of molecules within fluid

convection

what are the five functions of the cardiovascular system?

transport, washout, thermoregulation, protection, reproduction

which side is pulmonary

right

which side is systemic

left

are the circuits in series or parallel

series

what is the benefit to having the circuits in series

all of the blood goes to the same place

the volume of blood ejected by one ventricle in one minute

cardiac output

what is the formula for cardiac output

CO = SV x HR

what is the average heart rate

70 bpm

amount of blood pumped per beat

stroke volume

what is the average stroke volume

70 mL/beat

what is the average cardiac output

5 L/min

what part of the cardiovascular system has the most blood

veins

how much of the blood volume is in systemic veins and venules

60-70%

are organ circulations in series or parallel

parallel

what is the benefit to having organ circulations in parallel

can control the flow of blood to each organ independently

what is the formula for flow

Q = P/R

what is the pressure in the venae cavae

almost 0

what is darcy’s law

rearrangement of the flow equation

what is the resistance formula

R = P/Q

what is the pressure formula

P = Q x R

how can flow be increased

increasing pressure or decreasing resistance

how is local blood flow regulated

by changes in arteriole radius

what is the tunica intima made of

single sheet of epithelial cells

what is the function of the tunica intima

to protect against escape of plasma

what does the tunica intima secrete

vasoactive agents

what is the tunica media made of

smooth muscle

what is the function of the tunica media

mechanical strength and contraction

what is the tunica externa made of

connective tissue

what is the function of the tunica externa

to anchor blood vessels

what else does the tunica externa contain

smaller blood vessels and nociceptors

ring of connective “cardiac skeleton”

anulus fibrosus

what two functions does the anulus fibrosus have

insulates the chambers electrically and anchors the heart valve cusps

too much pericardial fluid

pericardial effusion

pulmonary artery to aorta in fetus

ductus arteriosus

shunt between left and right atrium in fetus

foramen ovale

which direction is a shunt and why

left to right due to pressure gradient

what symptoms do shunts present with

murmur, fatigue, and heart failure

what job do valves have

prevent backflow

what regulates the closure of valves

pressure

what is the right AV valve

tricuspid

what is the left AV valve

bicuspid/mitral

what do the chordae tendinae do

provide tension for the valves

what is the left semilunar valve

aortic

what is the right semilunar valve

pulmonary

which chamber receives blood from the venae cavae and coronary sinus

right atrium

which chamber contains the SA node

right atrium

what chamber ejects blood into the pulmonary artery

right ventricle

what chamber receives blood from the pulmonary veins

left atrium

what chamber ejects blood into the aorta

left ventricle

how is blood ejected by the left ventricle

reduction of diameter and size due to helical arrangement of myocardial fibers

describe the apex beat

when the LV contracts, it twists forward and the apex taps against the chest wall

when does ventricular filling occur

diastole

what happens during ventricular filling

ventricles fill with blood from the atria due to the pressure gradient, with a little atrial kick

what is the state of the valves during ventricular filling

AV valves are open, semilunar valves are closed

when does isovolumetric contraction occur

systole

what happens in isovolumetric contraction

ventricles depolarize and begin to contract

what is the state of the valves during isovolumetric contraction

AV valves close as pressure increases and semilunar valves remain closed

when does ventricular ejection occur

systole

what happens during ventricular ejection

blood is ejected from the ventricle as it contracts

what happens during ventricular ejection

AV valves remain closed and the increase in pressure opens the semilunar valves

when does isovolumetric relaxation occur

diastole

what happens during isovolumetric relaxation

venticles relax

what is the state of the valves during isovolumetric relaxation

AV valves remain closed, pressure gradient closes semilunar valves

volume of blood in the ventricle at the end of diastole

EDV

when does the pressure in the left ventricle peak

during ventricular ejection

what makes the dicrotic notch

brief backflow of blood into the ventricle as the AV valve closes

percent of EDV ejected during systole

ejection fraction

stroke volume formula

SV = EDV - ESV

ejection fraction formula

ejection fraction = (SV/EDV) x 100%

what is the average ejection fraction

60-65%

what is aortic pressure relative to atrial pressure

always higher

draw a healthy pressure-volume loop and label the axes, ventricular filling, isovolumetric contraction, ventricular ejection, isovolumetric relaxation, opening of the mitral valve, closing of the mitral valve, opening of the aortic valve, and closing of the aortic valve

what is left ventricular compliance a measure of

distensibility

what does a reduction in left ventricular compliance lead to

increased end diastolic pressure

what happens to the length of the cardiac cycle as heart rate increases

it decreases

how does the length of the cardiac cycle decrease

by decreasing diastole

what limits the maximum useful heart rate

diastole

what is S1 (lub) caused by

closure of AV valves

what is S2 (dub) caused by

closure of semilunar valves

ultrasound based tool for observing the motion of the walls and valves of the heart

echocardiography (echo)

catheter inserted into right and/or left heart

cardiac catheterization

radio-opaque contrast medium injected and its progress through the cardiac chambers is followed by x-ray

cardiac angiography

What does cardiac angiography help diagnose

Valve regurgitation and atherosclerosis

What is stenosis

Narrowing

Pressure in upstream chamber » pressure in downstream chamber during time of flow

Stenosis

Does stenosis increase or decrease the pressure gradient

Increase

What is regurgitation

Backflow

Retrograde flow of blood upstream during time when valve is normally closed

Regurgitation

What is the most common cause of valve disease

Degeneration

What is the most common valve abnormality

Aortic stenosis

What is a common cause of degeneration

Rheumatic fever

What are the 2 most common causes of aortic stenosis

Age-related wear and tear and calcification

What are the 3 manifestations of aortic stenosis

↑ LV pressure during ejection, LV hypertrophy, backup of blood into LA

aortic stenosis: what is a direct and indirect effect of increased LV pressure during ejection

direct is increased resistance to flow, indirect is decreased stroke volume

aortic stenosis: what is a direct effect of LV hypertrophy

impaired filling of ventricle

aortic stenosis: what is a direct effect of blood backup into LA

increased LA pressure

what is aortic stenosis a risk factor for

heart failure and arrythmia

what kind of murmur is aortic stenosis

systolic

what is the most common cause of mitral stenosis

rheumatic fever