overview of the function of the CVS Flashcards Preview

Cardiovascular system > overview of the function of the CVS > Flashcards

Flashcards in overview of the function of the CVS Deck (45)
Loading flashcards...
1
Q

what are the functions of the CVS?

A

it is a bulk flow system that transports: O2 and CO2, nutrients, metabolites, hormones, heat

2
Q

in what ways is the CVS flexible?

A

heart can vary output
vessels can redirect blood
vessels can store blood

3
Q

what is the normal cardiac output?

A

5L per minute

4
Q

what is the maximum cardiac output of the heart?

A

30L per minute

5
Q

when might blood be redirected?

A

during exercise when the skeletal muscles require more oxygen and so more blood

6
Q

are the left and right sides of the heart in series or parallel?

A

series

7
Q

given that the left and right side of the heart are in series what does this mean about ouput on each side?

A

it must be equal

8
Q

are most vascular beds in series or parallel with the heart?

A

parallel

9
Q

why are most vascular beds in parallel?

A
  • so all tissues receive oxygenated blood

- allows regional direction of blood

10
Q

why are the hypothalamus and anterior pituitary gland not in parallel?

A

so that hormones released by the hypothalamus are not diluted before the reach the anterior pituitary gland

11
Q

why are the gut and liver capillary beds in series?

A

so that nutrient and products of digestion can be processed by the liver before they reach the rest of the body

12
Q

generally what is the relationship between percentage of cardiac output to organs and % oxygen consumption of organs?

A

they are about equal

13
Q

why is % cardiac output and %O2 consumption not equal in the kidneys?

A

%cardiac output is much higher as blood has to pass through the kidneys to be filtered

14
Q

why is % cardiac output and %O2 consumption not equal in the skin?

A

%cardiac output is much higher than % O2 consumption, this is because blood has to travel to the skin to warm the peripheries

15
Q

is % cardiac output to the heart equal to its %O2 consumption ?

A

no % O2 consumption is much higher

16
Q

what is the equation for flow in the CVS?

A

flow= difference in pressure/resistance

17
Q

what is altered to alter flow?

A

the resistance of blood vessels, this is done by altering radius of vessels

18
Q

what is the pressure difference in the CVS?

A

Mean Arterial Pressure –

Central Venous Pressure

19
Q

which vessels control the resistance of vascular beds?

A

arterioles

20
Q

describe the vessels of the systemic CVS starting at the left side of the heart

A
  1. aorta
  2. arteries
  3. arterioles
  4. capillaries
  5. venules
  6. veins
21
Q

why does the aorta have an elastic wall?

A

to store energy during the contraction of the heart and use it to pump blood while the heart is relaxing

22
Q

what type of artery is the aorta?

A

elastic artery

23
Q

what is the name of the non-elastic arteries?

A

muscular arteries

24
Q

what is the structure and function of he muscular arteries?

A

wide lumen and strong non-elastic wall. They act as the low resistance conduit to transport blood to the peripheries as easily a possible

25
Q

what is the structure and function of arterioles?

A

narrow lumen and thick contractile wall. Allows control of resistamce and therefore flow, this allows regional redirection of blood

26
Q

describe the structure and function of capillaries?

A

narrow lumen and thin, single celled endothelial wall

27
Q

what are the capacitance vessels and why are they called this?

A

venules and veins. so called as like a capacitor stores current the capacitance vessels store blood.

28
Q

what is the structure of the capacitance vessels?

A

wide lumen, distensible, so they are a low resisitance conduit

29
Q

what is the capacitance vessels function during exercise?

A

the blood stored in these vessels can be utilised during exercise

30
Q

what separates the two sides of the heart?

A

interventricular septum

31
Q

what is the myocardium?

A

the muscle that makes up the wall of the heart

32
Q

what are the atriums?

A

the chambers that receive blood

33
Q

what are the ventricles?

A

the chambers that pump blood

34
Q

what is the aorta?

A

main artery, leaves the left side of the heart

35
Q

what are the vena cavae?

A

superior and inferior. receive deoxygenated blood form the superior and inferior of the body respectively

36
Q

what is the pulmonary trunk?

A

the portion of the pulmonary artery before it bifurcates

37
Q

what are the pulmonary veins?

A

vessels taking oxygenated blood from the lungs to the left atrium of the heart

38
Q

what is the aortic valve?

A

valve between left ventricle and aorta

39
Q

what is the pulmonary valve?

A

valve between the right ventricle and the pulmonary artery

40
Q

what is the mitral valve?

A

the valve between the left atrium and ventricle, has two “flaps”

41
Q

what is the tricuspid valve?

A

the valve between the right atrium and ventricle has three “flaps”

42
Q

what are the chordae tendinae?

A

cord-like tendons that connect the mitral and tricuspid valves to the myocardium

43
Q

what are the papillary muscles of the heart?

A

attached to the chordae tendinae, they’re function is to keep the chordae tendinae tight

44
Q

what are the functions of the tricuspid and mitral valves?

A

prevent blood moving back into the atriums of the heart while the ventricles condract

45
Q

what is the function of the chordae tendinae?

A

prevent the tricuspid and mitral valves inverting and allow backflow of blood