Intro to CV system

Question 1

Why do the 2 sides of the heart have to pump more or less the same amount of blood?

Answer 1

or else blood would accumulate

Question 2

what is transported as part of the bulk flow system of the heart?

Answer 2

metabolites 
oxygen & CO2 
hormones 
heat 
nutrients

Question 3

what is the significance of most vascular beds being in parallel?

Answer 3

• allows all tissued to receive oxygenated blood

- allows for the re-direction of blood

Question 4

what is the main function of blood?

Answer 4

to transport oxygen

Question 5

what is the flow equation ?

Answer 5

flow= difference in pressure/resistance
where difference in pressure= MAP-CVP
resistance = radius4

Question 6

what is pressure?

Answer 6

the force with which blood is pushed through the circulation

Question 7

what is resistance?

Answer 7

stops blood getting through

Question 8

what is capacitance?

Answer 8

the ability of the system to store blood

Question 9

describe elastic arteries and give an example of one

Answer 9

wide lumen, very elastic wall e.g. aorta

Question 10

describe muscular arteries

Answer 10

wide lumen, not very elastic wall e.g. other arteries

Question 11

describe arterioles and state their function

Answer 11

narrow lumen and contractile wall. Function= resistance vessels; allow regional redirection of blood

Question 12

describe capillaries and state their function

Answer 12

narrow lumen and thin wall. Function= gas exchange

Question 13

describe venules and veins

Answer 13

venules and veins are capacitance vessels. Wide lumen and distensible wall

Question 14

what is the function of the aortic and pulmonary valves and what are they also referred to as?

Answer 14

function= prevent back flow of blood from pulmonary trunk/ aorta back into RV/LV. Also referred to as semi-lunar valves (both have 3 cusps)

Question 15

what are the chordae tendinae

Answer 15

Chord like tendons which connect the bicuspid and mitral valves to the papillary muscles and prevent them from prolapsing or inverting

Question 16

when do semi-lunar valves open?

Answer 16

when there is a pressure change

Question 17

when do semi-lunar valves shut?

Answer 17

when the pressure of the chamber they are leading into exceeds that of the chamber before