VASCULAR LECTURE 1: Htn & atherosclerosis

Question 1

What values are considered hypertension?

Answer 1

> 135 / >85

Question 2

What is BP >180 / >120 considered as?

Answer 2

Hypertensive crisis

Question 3

What is blood pressure the product of?

Answer 3

Cardiac output x peripheral resistance

Question 4

What are 3 things cardiac output is determined by?

Answer 4

Blood volume, heart rate, contractility

Question 5

What 2 things determine blood volume?

Answer 5

Sodium, kidney function

Question 6

What are 2 categories of factors that determine blood vessel diameter?

Answer 6

Humoural factors (endocrine)
Neural factors

Question 7

Name some examples of endocrine factors that cause contriction in peripheral vessels

Answer 7

Angiotensin II
Catecholamines
Thromboxane
Leukotrienes
Endothelin

Question 8

Name some examples of endocrine factors that cause dilation in peripheral vessels

Answer 8

Prostaglandins
Kinins
NO

Question 9

What neural factors cause constriction in peripheral vasculature?

Answer 9

Alpha adrenergic

Question 10

What neural factors cause dilation in peripheral vasculature?

Answer 10

Beta adrenergic

Question 11

Which kind of hypertension is the most common, and is due to an idiopathic cause, like non-specific lifestyle/genetic factors?

Answer 11

Primary/essential hypertension

Question 12

Which kind of hypertension is more rare (5-10%) and is due to an identifiable cause, eg water/salt imbalance?

Answer 12

Secondary hypertension

Question 13

What are two main problems that cause arterial flow disorders?

Answer 13

1. Narrowed/blocked arterial lumen
2. Weakening of arterial walls leading to aneurysm/rupture

Question 14

What is the name of the layer where atherosclerotic plaques develop?

Answer 14

Intima

Question 15

What are the 3 layers of a plaque?

Answer 15

1. Fibrous cap
2. Necrotic center
3. Media

Question 16

What are 3 main components of the fibrous cap?

Answer 16

1. Cells (smooth muscle, macrophages, immune cells)
2. ECM (collagen, elastic fibers, proteoglycans)
3. Lipids (intra and extracellular)

Question 17

What are 2 complicaitons that can happen to plaques?

Answer 17

1. Vaso vasorum may hemorrage inside plaque
2. Calcification

Question 18

What is the earliest sign of atherosclerosis?

Answer 18

Fatty streak on arterial walls

Question 19

Why is diabetes a risk factor for atherosclerosis?

Answer 19

Vascular inflammation caused by hyperglycemia

Question 20

Why is smoking a risk factor for atherosclerosis?

Answer 20

Chemicals are vasoconstrictors, cause endothelial damage

Question 21

Why must lipids be converted to lipoproteins for metabolism?

Answer 21

Lipids are hydrophobic, so must be combined with proteins to become water soluble and interact with cell membrane receptors

Question 22

What is the difference between the exogenous and endogenous pathways of lipids entering the blood?

Answer 22

Exogenous: From diet
Endogenous: Synthesized by liver

Question 23

In the exogenous pathway of lipids entering the bloodstream, fatty acids are absorbed by the small intestine and packaged into what?

Answer 23

Chylomicrons

Question 24

After chylomicrons are formed, how are they transported into the blood?

Answer 24

Via lymphatic system

Question 25

In the endogenous pathyway of lipids entering the bloodstream, the liver assembles triglycerides and fatty acids into what?

Answer 25

VLDLs (very low density lipoproteins)

Question 26

How do VLDLs become LDLs?

Answer 26

Triglycerides are removed by various cells

Question 27

In what form does the majority of blood cholesterol move through the body?

Answer 27

LDLs (low density lipoproteins)

Question 28

What is the danger of high levels of LDLs in the blood?

Answer 28

They can be taken up by "unauthorized" tissues

Question 29

What are 2 pieces of evidence correlating hypercholesterolemia with atherosclerosis?

Answer 29

1. The majority of lipids in plaques are mainly cholesterol 2. Reducing LDL levels has been shown to slow atherosclerosis or even cause regression

Question 30

What is the trigger in pathogenesis of an atherosclerotic plaque?

Answer 30

Damage to endothelium which leads to increased permeability and cell adhesion (inflammation)

Question 31

How is the initial lesion formed in atherosclerosis? (2 points)

Answer 31

1. Endothelial cells release inflammatory mediators to recruit T cells and smooth muscle cells 2. Macrophages and lipids infiltrate into the intima

Question 32

How is the fatty streak formed in atherosclerosis? (2 points)

Answer 32

1. Macrophages take up lipids and become foam cells 2. LDLs accumulate and oxidize

Question 33

How is the intermediate lesion formed in atherosclerosis? (2 points)

Answer 33

1. Smooth muscle cells proliferate and produce extracellular matrix, thickening the vessel wall 2. Cells die, causing lipid debris to accumulate

Question 34

How is an atheroma formed in atherosclerosis?

Answer 34

The plaque's core of extracellular lipid becomes necrotic

Question 35

What are 2 things that characterize an atherosclerotic plaque as a fibroatheroma?

Answer 35

1. Single or multiple lipid cores 2. Fibrotic/calcified layers

Question 36

What are 3 things that characterize an atherosclerotic plaque as a complicated lesion?

Answer 36

1. Surface defect 2. Erosion of vasa vasorum causes hemorrhage into the plaque 3. Thrombosis