CV5

Question 1

as force of contraction increases, _________ increases

Answer 1

stroke volume

Question 1

what are the 2 forces that determine the force generated by cardiac muscle

Answer 1

the contractility of the heart
the length of the muscle fibres at the beginning of contraction

Question 2

what determines the length of muscle fibres at the beginning of contraction

Answer 2

the amount of blood in the ventricle (EDV)

Question 3

what is the contractility of the heart

Answer 3

the strength of the muscles contraction when it receives a signal to beat

Question 4

what is contractibility controlled by

Answer 4

nervous system and endocrine system

Question 5

what is a chemical that affects contractibility called

Answer 5

inotropic agent

Question 6

what is an inotropic agents influence referred to

Answer 6

inotropic effect

Question 7

what are chemicals that would increase contractility of the heart? what kind of effect is that

Answer 7

epinephrine
it would be a positive inotropic effect

Question 8

whats the main determinant of contractility

Answer 8

the sympathetic branch of the autonomic system

Question 9

does cardiac muscle like to be stretched or no

Answer 9

it likes to be stretched because it generates the most force when it is stretched

Question 10

increasing sarcomere length in cardiac muscle increases __________

Answer 10

stroke volume

Question 11

what is the frank starling law of the heart

Answer 11

stroke volume increases with increasing end diastolic volume

Question 12

what is preload

Answer 12

the degree of myocardial stretch prior to contraction

Question 13

what is EDV normally determined by

Answer 13

venous return

Question 14

what is venous return

Answer 14

the flow of blood back to the heart through the veins

Question 15

what are the three factors affecting venous return

Answer 15

1. skeletal muscle pump
2. respiratory pump
3. sympathetic contraction of veins

Question 16

what is after load

Answer 16

the resistance that the heart must overcome in order to open the aortic valve (overcoming the pressure in the aorta)

also applies to pulmonary

Question 17

what does bigger after load cause

Answer 17

hypertrophy of the heart (causes your heart to work harder)

Question 18

does blood flow ever stop

Answer 18

nope

Question 19

what is considered the pressure reservoir

Answer 19

systemic arteries

Question 20

what controls the blood flow when your ventricle is relaxing

Answer 20

recoil of large arteries

Question 21

what can arterioles do

Answer 21

they can change resistance and redirect blood flow

Question 22

what is there the greatest number of in your circulatory system

Answer 22

capillaries

Question 23

where does exchange between blood and cells (interstitial fluid) happen

Answer 23

capillaries

Question 24

what are venules

Answer 24

where “capillaries” converge
becoming one large vein

Question 25

what is considered to be the volume reservoir

Answer 25

systemic veins

Question 26

what is the progressive branching of vessels (7)

Answer 26

aorta
arteries
arterioles
capillaries
venules
veins
vena cava

Question 27

what do all vessels contain

Answer 27

thin layer of endothelial cells

Question 28

which vessels are all 4 tissues

Answer 28

artery and veins

Question 29

what vessel only has endothelium cells

Answer 29

capillaries

Question 30

what does an arteriole have for tissues

Answer 30

endothelium and smooth muscle

Question 31

what does a venule have for tissue

Answer 31

endothelium and fibrous tissue

Question 32

what are the 4 tissues/cells around vessels

Answer 32

inner to outer:
endothelium cells
elastic tissue
smooth muscle
fibrous tissue