ch 7 exam 2

functions of the cardiovascular system

deliver o2 and other nutrients, remove co2 and other wastes, transport hormones, support temperature balance, control fluid regulation, maintain acid base balance, regulate immune functions

3 circulatory elements of cardiovascular system

the pump, tubes, fluid medium

what is considered the pump

the heart

what is considered the tubes

blood vessels

what is considered the fluid medium

blood

how does the heart drive blood through vessels

generating pressure

Order of blood flow through the heart

1. superior/inferior vena cava 2. right atrium 3. tricuspid valve 4. right ventricle 5. pulmonary valve 6. to lungs 7. left/right pulmonary veins 8. left atrium 9. bicuspid valve 10. left ventricle 11. aortic valve 12. aorta

what is the right side of the heart considered

pulmonary circuit

right side of the heart pumps

oxygen poor blood

what is the left side of the heart considered

systemic circuit

left side of the heart pumps

oxygen rich blood

what is a part of pulmonary circuit

superior/inferior vena cava, - ra- tricuspid valve- rv- pulmonary valve- pulmonary artery- lungs

what is a part of systemic circuit

lungs- pulmonary veins- la- mitral valve- lv- aortic valve- aorta

arteries

carry blood away from heart

arterioles

control blood flow

capillaries

provide site for nutrient and waste exchange

venules

collect blood from capillaries

veins

carry blood from venules back to heart

myocardium

heart muscle

which part of the heart has the most myocardium

left ventricle to pump the blood to entire body

skeletal muscle location

throughout body

cardiac muscle location

in heart

appearance of skeletal muscle

long, cylindrical, striated, multiple nuclei

appearance of cardiac muscle

short fibers, striated, single nuclei

activity of skeletal muscle

produce moveemnt

activity of cardiac muscle

continuous rhythmic contraction

types of skeletal muscle

type i, iia, iix

types of cardiac muscle

only 1 type

stimulation of skeletal muscle

voluntary

stimulation of cardiac muscle

involuntary

what supplies the right side of the heart

right coronary artery

what supplies the left side of the heart

left main coronary artery

athrosclerosis

coronary artery disease

spontaneous rhythmicity

special heart cells generate and spread electrical signals

how do the electrical signals spread

via gap junctions

normally, how would the SA node set the HR to

100 bpm

what stops the SA node from setting the heart rate to 100bpm

the parasympathetic nervous system

cardiac conduction system

sa node, av node, av bundle, left and right bundle branches, purkinje fibers

sa node

initiates contraction signal

av node delays and relays signal to ventricles

av bundle relays signal to rv and lv

purkinje fibers

send signal to rv and lv

parasympathetic nerve acts directly on heart via

vagus nerve

sympathetic nerve acts directly on heart via

cardioacceleratory center

what does parasympathetic ns release in heart

ach

what does ach do to cells

hyperpolarize

parasympathetic ns ____ heart rate

decreases

normal resting hr

60-100 bpm

elite athlete hr

35 bpm

what does sympathetic ns release in heart

norepinephrine

what doe norepinephrine do to cell

depolarization

sympathetic ns ____ heart rate

increases

what does sympathetic ns heart rate determine

hr during physical, emotional stress

electrocardiogram

record hearts electrical activity

what disease can an ekg detect

coronary artery disease

3 basic phases of ekg

p-wave, qrs complex, t wave

p wave

atrial depolarization

qrs comples

ventricular depolarization, atrial repolarization

t wave

ventricular repolarization

cardiac cycle

all mechanical and electrical events occurring in one heart beat

diastole

relaxation phase

during diastole chambers

fill with blood

systole

contraction phase

ventricular systole occurs

qrs complex to t wave

how much does systole take up of the cardiac cycle

1/3

what happens to atrioventricular valves during systole

close

what happens to semilunar valves during systole

open

what happens to blood in systole

gets ejected

end systolic volume

volume of blood remaining in each ventricle after systole

what makes the lub sound

AV valves closing

ventricular diastole occurs

t wave to next qrs complex

how much does diastole take up of the cardiac cycle

2/3

what happens to ventricular pressure in diastole

drops

what happens to atrioventricular valves during diastole

open

what happens to semilunar valves during diastole

close

how much does blood fill passively during diastole

70%

how much does blood fill by atrial contraction during diastole

30%

end diastolic volume

volume of blood in each ventricle at end of ventricular diastole

stroke volume

volume of blood pumped in one heartbeat

when does stroke volume occur

during systole

formula for stroke volume

EDV-ESV

ejetion fraciton

percentage of end diastolic volume pumped

formula for ejection fraction

SV/EDV

what can ejection fraction tell us

if heart is contracting in a healthy manner

cardiac output

total volume of blood pumped per minute

resting cardiac output

4.2 to 5.6 L/min

average total blood volume

5 L

how often does total blood volume circulate

every minute

functional syncytium

pumping of the heart as one unit

how does functional syncytium occur

gap junctions

torsional contraction

increased contractility during intense exercise to enhance left ventricle filling

during torsional contraction, systole

heart twists gradually and stores energy

during torsional contraction, diastole

untwisting and allows atrial filling

frank starling mechanism

increase stretch from increase filling resulting in increase contractile force and decreased ESV

systolic blood pressure

highest pressure in artery

diastolic blood pressure

lowest pressure in artery

mean arterial pressure

average pressure over entire cardiac cycle

what drives flow

pressure force

how is pressure provided

by heart contraction

what is required by all tissues

blood flow

resistance

force that opposes flow