Brainscape's Knowledge GenomeTM

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


See full index

Semester 2 - CVS > Session 1 - Introduction to Histology of the CVS > Flashcards

Session 1 - Introduction to Histology of the CVS Flashcards

1
Q

How does exchange occur between blood and tissues?

A

Diffusion

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

Give three factors which affect rate of diffusion

A

Area available for exchange
Diffusion ‘resistance’
Concentration gradient

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

What affect does increased capillary density have and why?

A

Increased rate of diffusion as larger surface area for diffusion

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

What do highly metablolically active tissues have?

A

A high capillary density

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

Why is area available for exchange conisdered a maximum?

A

Because not all capillaries are perfused

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

In the body is area
a) Rate Limiting
or
b) Not rate limiting

A

It is b, not rate limiting

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

What are the three factors which affect diffusion resistance?

A

Nature of molecules crossing the capillaries
Nature of the barrier
Path length

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

How do lipophillic molecules reach cells from capillaries?

A

By directly crossing capillary wall due to the nature of the lipid bilayer of endothelial cells

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

How do hydrophillic molecules reach cells?

A

Pass through pores, which offer little resistance

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

What property do small moleules posses when compared to large?

A

Diffuse more easily

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

How the nature of the barrier affect diffusion?

A

Increasing pore size and number facilitates the diffusion of large and hydrophillic molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does path length depend on?

A

Capillary density and interstitial space

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

How does conc gradient affect diffusion?

A

The greater the concentration gradient, the greater the rate of diffusion. Must be maintained in order for exchange to continue.

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

What is the conc gradient in capillaries between?

A

Capillary contents and nearby cells

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

What is the most important variable in conc grad?

A

The flow of blood

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

What happens if blood is not supplied at appropriate rate?

A

Conc grad driving exchange will dissipate, and nutrients will not be supplied at the right rate

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

What is the cardiac output of an average male at rest?

A

5 l/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the minimum rate of blood flow required by the brain?

A

750 ml/min

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

What three organs must have blood at ALL times?

A

Kidney, heart muscle and brain

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

What are the four main components of circulation?

A

Pump
Distribution vessels
Flow control
Capacitance

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

What is the bodies pump?

A

Take a guess, wise guy.

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

What is the bodies main distribution vessels for circulation?

A

Arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What type of vessels are used in flow control?

A

Resistance vessels, such as arterioles and pre-capillary sphincters

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

What two things do resistance vessels ensure?

A

Blood flow to areas of the body which are difficult to perfuse
Blood flow is restricted to areas which are easy to perfuse

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

What is capacitance?

A

Store of blood to be called upon to cope with temporary imbalances between the amount of blood returning to the heart and the amount that is required to pump out.

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

Where is capacitance generated?

A

In the veins

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

What is the function of an artery?

A

Carry blood away from the heart to the capillary beds

28
Q

Give two types of artery

A

Elastic (conducting) or muscular (distributing)

29
Q

What are arterioles?

A

Arteries with a diameter of less than 0.1mm

30
Q

What are capillaries?

A

Vessels 7-10 micrometers in diameter

31
Q

What is a post capillary venule?

A

Receive blood from capillaries, have a diameter of 10-30 micrometers and are even more permeable than capillaries

32
Q

What is a merging venule?

A

Diameter more than 50 micrometers. Tunica media reappears

33
Q

describe a vein

A

Very large diameter
Thin wall with more connective tissues
Fewer elastic and muscle fibres
Usually have semi-lunar valves

34
Q

What are veins and arteries comprised of?

A

Three layers

Tunica intima, media and adventitia

35
Q

Describe the tunica intima of elastic arteries

A

Endothelial cells with long axes parallel to axis of artery

Narrow subendothelium of CT with discontinuous internal elastic limina

36
Q

Why do epithelial cells in tunica intima of elastic arteries have endothelial cells with long axes parallel to axis of artery

A

to reduce friction

37
Q

Why does the tunica intima of elastic arteries have a narrow subendothelium of CT with discontinuous internal elastic lamina?

A

to allow for expansion

38
Q

Describe the structure of the media of elastic arteries

A

40-70 layers of fenstrated elastic membrane, with smooth muscle and collagen between these lamellae.

39
Q

How is the smooth muscle in the media of elastic arteries controlled?

A

Smooth muscle is involuntary and allows for controlled contraction in order to move the blood through the lumen

40
Q

Describe the adventitia of elastic arteries

A

Thin layer of fibroelastic CT containing lymphatic vessels and nerve fibers

41
Q

Describe the intima of muscular arteries

A

Endothelium, subendothelium, thick internal elastic lamina

42
Q

Describe the media of muscular arteries

A

40 layers of smooth muscle cells connected by gap junctions

Prominent external elastic lamina

43
Q

Why is does the media of muscular arteries have 40 layers of smooth muscle cells connected by gap junctions?

A

For coordinated contraction

44
Q

Describe the structure of the adventitia of muscular arteries

A

Thin layer of fibroelastic CT with nerve fibers

Vasa vasorum

45
Q

Why does the adventitia of the arteries have nerves?

A

For vasoconstriction and dilation

46
Q

What are vasa vasorum?

A

Dekiever blood to tissues in muscular artery which are inadquately nourished by luminal blood

47
Q

Describe the structure of the intima of arterioles

A

Endothelium and thin subendothelium

48
Q

Describe the structure of the media of arterioles

A

1 to 3 layers of smooth muscle

49
Q

Describe the structure of the adventitia of arterioles

A

Hardly present

50
Q

How do metarterioles differ from arterioles?

A

Smooth muscle layer discontinuous. spaced apart and encircle endothelium of capillary arising from metarterioles, forming pre-capillary sphincter

51
Q

What is a pre-capillary sphincter?

A

Formed from metarterioles, can contract and prevent blood flow into capillary bed

52
Q

Describe the structure of capillaries

A

Single layer of endothelium with basement membrane

53
Q

Give three types of capillary

A

Continous, fenstrated and sinusoidal

54
Q

what is a fenstrated capillary?

A

Interruptions between thin parts of endothelium

55
Q

What is a sinusoidal capillary?

Where are they found?

A

Large diameter, special linings and an incomplete basal lamina which allows blood cells to enter tissue space.

Liver, spleen and bone marrow

56
Q

Why are venules more permeable than capillaries?

A

Lower pressure so fluids tend to drain into them

57
Q

Describe the structure of merging venules

A

Intima - endothelium or thin smooth muscle form thin wall
Valves which are thin extensions of intima and prevent backflow
Media - 2 to 3 layers of smooth muscle

58
Q

Describe the intima of veins

A

Thicker tunica intima than venules (smooth muscle, valves)

59
Q

Describe the media of veins

A

2 to 3 laers of smooth muscle

60
Q

When does the media of veins differ?

A

In superficial veins of leg, where muscle thick to resist distension caused by gravity

61
Q

Adventitia of veins?

A

Well developed

62
Q

What is a vena comitante?

A

A vein or usually a pair of veins found either side of and artery whose pulsations aid venous return

63
Q

What happens to veins if pressure is not maintained?

A

They collapse

64
Q

How is pressure in arteries maintained?

A

Systolic blood flow

65
Q

How is blood pressure in veins maintatined?

A

The muscle pump action in the leg and pressure factor in abdominal and thoracic cavity

66
Q

Name three structures blood vessels do not reach in body

A

Cartilage, epithelia and cornea

Semester 2 - CVS (15 decks)

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