Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FM1020 > PHYSIOLOGY - Circulatory System > Flashcards

PHYSIOLOGY - Circulatory System Flashcards

1
Q

What % of total blood volume is in the systemic circulation when at rest?

A

84%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What % of total blood volume is in the heart and lung circulation when at rest?

A

16%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is micro circulation ?

A

Arterioles, capillaries and venues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are conduits?

A

Elastic arteries - i.e aorta and other large arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are resistance vessels?

A

Muscular arteries i.e arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Arterioles are not very well innervate t/f?

A

False. They are well innervated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are exchange vessels?

A

Capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Is the pressure higher in the arterial system or the venous system ?

A

Arterial system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which contains most of the blood in the circulatory system, the veins or the arteries?

A

Veins - they act as a blood reservoir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are capitance vessels?

A

The veins. They act as blood reservoirs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is venous return to the heart assisted?

A
  • Skeletal muscle pump
  • Contraction of diaphragm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which have a wider diameter, veins or arteries?

A

Veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How many capillaries are there in an average human?

A

3 billion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Veins are highly distensible t/f?

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What allows blood to be stored in the venous system?

A

The highly distensible veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define blood pressure

A

The pressure of blood in the heart/circulatory system exerted outwards onto a unit are of the vessel wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 2 physical laws of blood flow and pressure?

A
  1. Blood flows from a region of high pressure to a region of low pressure ( P1-P2 = ΔP )
  2. The rate of blood flow is directly proportional to ΔP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the normal blood pressure in the veins which are emptying into the heart?

A

0mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is normal aortic pressure?

A

90mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is ΔP for the systemic circulation and how is it calculated?

A

ΔP = 90mmHg

Calculated by subtracting vena cava pressure from aortic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is normal ΔP for the pulmonary circulation?

A

20mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does resistance to blood flow depend on?

A
  1. Length of blood vessels
  2. Radius of blood vessels
  3. Viscosity of blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is blood viscosity ?

A

The resistance to blood flow caused by blood cells rubbing against each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the relationship between rate of blood flow (F) and resistance

A

F is inversely proportional to resistance

F = ΔP/R (Ohm’s Law)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What symbol denotes resistance? (poiseuille’s law)

A

R

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What symbol denotes length of blood vessels? (poiseuille’s law)

A

L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What symbol denotes viscosity of blood? (poiseuille’s law)

A

η ( greek letter ‘eta’ )

28
Q

What are the major regulators of blood flow?

A
  • mean arterial pressure
  • vascular blood vessel diameter
  • blood viscosity
29
Q

Where does most resistance to flow originate and what % ?

A

65% in small arterioles

30
Q

Explain the fourth power law.

A

Small changes in diameter of a blood vessel can result in large changes in resistance (r^4 where r is radius of the blood vessel )

31
Q

What component of blood highly affects the viscosity of blood?

A

Haemocrit

32
Q

Who normally has a higher haemocrit, males or females?

A

Males

33
Q

What is the viscosity of normal blood?

A

Roughly 3 times that of water

34
Q

What can happen to viscosity, and blood flow in someon with polycythaemia?

A
  • blood viscosity can dramatically increase
  • this increases resistance and blood flow can be compromised
  • heart has to pump harder to overcome the resistance
  • this means that blood flow to some tissues may be compromised
35
Q

What can happen to blood viscosity in somebody with sever anaemia ?

A

It can drop to 1.5 times the viscosity of water

36
Q

What happens to the blood flow of someone with severe anaemia and what are the effects?

A
  • blood flows far faster than normal due to decreased resistance
  • increased venous return and cardiac output
  • hypoxia causes blood vessels to dilate, further increasing cardiac output
  • there is a sustained increase in the pumping workload of the heart.
37
Q

How can you increase ΔP?

A
  • increase in flow
  • increase in resistance
38
Q

What is the definition of compliance/capitance?

A

The volume of blood which can be stored in a blood vessel for each mmHg pressure rise

39
Q

What is the equation for compliance ?

A

Compliance = distensibility x volume

Ca = ΔV/ΔP

40
Q

What determines distensibilty and thus compliance ?

A
  1. Quantity of elastin fibers in the vessel wall
  2. Wall thickness
41
Q

How do large arteries act as pressure reservoirs?

A
  • during systole, ejected blood causes the elastic walls of the aorta to expand
  • during diastole, the walls recoil, maintaining blood flow through vasculature
42
Q

Blood flow is pulsation t/f?

A

False. It is continous due to the hydraulic filter created by aorta

43
Q

Does the elastin content of your arteries stay the same throughout your life?

A

No. Elastin replaced with collagen as you age

44
Q

What happens when the walls of arteries become rigid?

A

The walls cannot distend
Pressure increases during systole
This increases the afterload

45
Q

Do compliant artieries increase/reducer the workloads of the heart?

A

Reduce

46
Q

Do rigid artieries increase/reducer the workloads of the heart?

A

Increase

47
Q

How are b.p measurements quoted?

A

Systolic pressure / diastolic pressure

48
Q

Why is the mean arterial pressure calculated ?

A

Because arterial pressure is pulsatile

49
Q

How do you calculate MAP?

A

MAP = diastolic p + 1/3(systolic-diastolic)

50
Q

Why is the value of MAP closer to diastolic pressure?

A

Diastole lasts twice as long as systole

51
Q

What is hypertension?

A

elevated b.p

52
Q

What % of adults have hypertension?

A

20%

53
Q

What are the two types of hypertension?

A
  1. Essential hypertension
  2. Secondary hypertension
54
Q

What is the cause of essential hypertension?

A

Mainly unclear- could be diet, genetics etc.

55
Q

What % of hypertension cases are essential hypertension?

A

95%

56
Q

What causes secondary hypertension?

A

It results from another condition e.g renal disease

  • chronically elevated salt and water reabsorption in the nephron increases blood volume , therefore raising b.p
57
Q

Why is hypertension bad for health?

A
  • causes long term damage to heart, kidneys, blood vessels
  • risk factor for heart attack and stroke
58
Q

Why does hypertension cause damage to the heart?

A

The heart must contract stronger in order to overcome teh increased afterload

59
Q

Why does hypertension put someone at risk for a stroke/heart attack ?

A
  • promotes formation of atherosclerotic plaques
60
Q

How do you calculate pulse pressure?

A

Systolic pressure - diastolic pressure = pulse pressure

61
Q

When is the dicrotic wave visible on the blood pressure wave?

A

During the diastolic phase of a young healthy person

62
Q

What causes the dicrotic wave?

A
  • recoil of blood from closed aortic valve
  • reflection of systolic pressure wave back from small arteries in the lower body
63
Q

What causes pulse pressure ?

A
  • LV contraction creates a pulse of systolic pressure as blood isi pushed into arteries.
  • the pulse is transmitted through the elastic walls of large arteries
  • velocity of pulse transmission is 15x the velocity of blood flow
  • the pressure changes the diameter of the artery so it can be felt by palpitation
64
Q

At rest what % of blood is stored in the veins?

A

64%

65
Q

What is the term used to describe the fact that aorta maintains blood flow by recoiling?

A

Hydraulic filter

66
Q

Why does hypertension increase risk of atherosclerotic plaques?

A

It damages the endothelial lining of the blood vessels which causes and increased tendency fro atherosclerosis

FM1020 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions