Brainscape's Knowledge GenomeTM

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


See full index

Medsci 203 (my own) > L19 Atherosclerosis > Flashcards

L19 Atherosclerosis Flashcards

1
Q

Atherosclerosis is a disease affecting…

A

the inner most layer of large and medium arteries

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

Atherosclerosis is characterised by:

A

Focal thickenings of plaque which are deposits of fibrous tissues and lipids

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

What are the three concentric layers?

A

Tunica intima, media, externa/adventitia

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

The endothelial cells are seperated by

A

Tight junctionsWh

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

What is the structure of tunica intima?

A

Single layer of endothelial cells on basement membrane

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

What are myointimal cells?

A

Contractile cells scattered through the basement

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

What are the five functions of endothelial cells?

A
  • Provide barrier between blood and underlying tissues
  • Act as a gatekeeper to the process of inflammation
  • Regulate blood pressure by regulating contraction of vascular smooth muscle cells
  • control haemostasis as they produce enzymatic and chemical inhibitors of platelet activation.
  • Determine long term vessel regression vs new vessel growth (angiogenesis) in response to tissue needs.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does the tunica media regulate flow?

A

Via contraction of the muscle cells

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

How does the tunica media stabalise endothelial cels?

A

Secrete ECM and activating TGF-b

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

What does the elastic lamina look like when stained?

A

Wavy and pink

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

In small vessels, where are elastic lamina layers found?

A

On either side of tunica media

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

What is the function of elastic lamina?

A

To assist with continuous flow

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

What is the tunica externa?

A

Tunica externa is connective tissue found on the very outside of the blood vessel

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

What does the tunica externa contain?

A

Fibroblasts, leukocytes, nerves, lymphatics, blood vessels (vasa vasora)

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

What is the structure of the tunica media in arterioles (small branches within tissues)?

A

Smallest, single later of smoth muscle cells (sometimes called pericytes).

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

What is the structure of the tunica media in muscular arteries (i.e. coronary artery)

A
  • Media contains large amounts of smooth muscle cells
  • Few elastic fibres scattered through them
  • Seperate internal/external elastic laminae on either side
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the structure of tunica media in large elastic arteries (i.e. aorta, common carotid)?

A
  • Prominent elastic laminae in their media to support the immense pulsatile carotid.
  • Internal/external elastic laminae continuous (thus, cannot be distinguished)
  • Elastic recoil assists with continuous flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Is the aetiology of Atherosclerosis completely understood?

A

No

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

What is the geographical variation of incidence of Atherosclerosis?

A

Western countries are more affected, but other regions are also affected

20
Q

What are the positive risk factors of atherosclerosis?

A
  • Hyperlipidaemia (high conc of lipids esp cholesterol)
  • cigarette smoking
  • hypertension
  • Diabetes
  • Advancing age
  • Polygenic inheritance
  • Males > females due to oestrogen protection
21
Q

What are the negative risk factors of atherosclerosis?

A
  • High levels of HDL –> carrying lipids away from B.V. to center of body)
  • Low alcohol consumption
  • Cardiovascular fitness (development of collateral vessels) - provide alternative routes for those that have Atherosclerosis.
22
Q

What is known to be the most important initiator of Atherosclerosis?

A

Endothelial cell injury

23
Q

What may cause endothelial cell injury?

A

Combination of:
- Hypertension leading haemodynamic forces of blood particularly at junctions/branch points
- Chemical insults (cigarette smoke, lipids)
- Cytokines

24
Q

What can endothelial cell injuries lead to?

A
  • Altered permeability (lipid infiltration - contributing to accumulation of fats and cholesterol deposits)
  • Adhesion of leukocytes (inflammation)
  • Thrombosis
  • Endothelial progenitors are recruited
25
Q

Leukocyte migration into the developing plaque is a form of ____ inflammation

A

Chronic

26
Q

What happens when monocytes enter Atherosclerosis plaque?

A

Differentiate into macrophages

27
Q

What happens when macrophages are in the plaque?

A

They ingest large amounts of oxidised lipoproteins which give them a foamy appearance, so they are called foam cells.

28
Q

What happens to the cell contents when macrophages die?

A

Cytoplasmic contents including digested lipids scape into extracellular space. If lipids are of a high concentration, they can crystalise, forming cholesterol clefts.

29
Q

What other types of cells might be present?

A

T-lymphocytes, mast cells, neutrophils, dendritic cells

30
Q

What causes activation of vascular smooth muscle cells?

A

Macrophages, platelets, and endothelial cells release growth factors - which activate smooth muscle cells.

31
Q

What happens once vascular smooth muscle cells are activated?

A
  • They migrate into the tunica intima from media
  • Lay down ECM and thus contribute to atherosclerotic plaque - contributes to fibrous cap which may later be degraded by matrix-degrading protease enzymes
  • Ingest lipids and interact with other cell types in the plaque through adhesion molecules present on their surface and through the growth factors they secrete
32
Q

What may accelerate smooth muscle activation and activity?

A
  • Failure of internal elastic laminae
  • Infection of vascular smooth muscle cells.
33
Q

What is CHIP?

A

Clonal hematopoiesis of indeterminate potential (CHIP)

34
Q

What happens in CHIP?

A

CHIP is a mutation in a single STEM cell in the bone marrow. These mutations gradually proliferate and take over the bone marrow, so that all or large portion of STEM cells carry CHIP. STEM cells that carry CHIP produce leukocytes in the periphery that can get inside atherosclerotic plaques.

This drives the process of atherosclerosis more quickly than non-mutated, normal leukocytes.

It is a modifiable factor of atherosclerosis.

35
Q

Which genes are affected in CHIP?

A

DNMT3A, TET2, ASXL1

36
Q

Which modifiable factors can increase or decrease the rate of Atherosclerosis?

A
  • Presence of CHIP
  • Failure of internal elastic laminae
37
Q

Why don’t lipoproteins enter the tunica media when it enters the plaque?

A

The internal elastic laminae forms a protective barrier

38
Q

What happens to lipoproteins in plaques?

A

Become oxidised

39
Q

What do oxidised lipoproteins induce?

A

Attract monocytes, release cytokines and growth factors, causing dysfunction and apoptosis in smooth muscle cells, macrophages and endothelial cells.

40
Q

In a pre-clinical phase, atheromas (Atherosclerosis plaque) are often…

A

Silent, fatty streak, fibrofatty plaque, advanced/vulnerable plaque

41
Q

Plaques become unstable due to…

A

High lipid content, inflammation, thin fibrous cap and luminal aspect of plaque

42
Q

Plaques can suddenly cause symptoms due to…

A

Rupture, haemorrage, occlusion by thrombus, critical stenosis.

43
Q

What are common clinical consequences of atherosclerosis?

A

Heart attack, peripheral vascular disease, strokes.

44
Q

What is haemorrage?

A
45
Q

What is occlusion by thrombus?

A
46
Q

What is critical stenosis?

A

Medsci 203 (my own) (18 decks)

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