Unit 2.7 - Cardiovascular Disease

Question 1

What is atherosclerosis?

Answer 1

The accumulation of fatty material consisting mainly of cholesterol, fibrous material and calcium forming an atheroma or plaque beneath the endothelium

Question 2

How does atherosclerosis effect arteries and blood pressure?

Answer 2

As they Atheroma grows the artery thickens and loses its elasticity. The diameter of the lumen becomes reduced and bloodflow becomes restricted resulting in increased blood pressure

Question 3

What is arthrosclerosis of the root cause of?

Answer 3

Various cardiovascular diseases

Question 4

What happens when atheroma ruptures?

Answer 4

• Rupture damages endothelium
• Damage releases clotting factors that activate a cascade of reactions resulting in the conversion of the enzyme prothrombin to its active form thrombin t

Question 5

What does thrombin cause?

Answer 5

Thrombin causes molecules of the plasma protein fibrinogen to form threads of fibrin
The fibrin threads form a meshwork that clots the blood, seals the wound and provides a scaffold for the formation of scar tissue
The formation of a clot (thrombus) is referred to as thrombosis

Question 6

What happens if a thrombin breaks loose?

Answer 6

It forms an embolus which travels through the bloodstream until it block a blood vessel

Question 7

What can a thrombus in an artery in the brain lead to?

Answer 7

• Lead to a stroke

* Cells are deprived of oxygen leading to death of tissue

Question 8

What can a thrombosis in a coronary artery lead to?

Answer 8

A myocardial infarction (MI) commonly known as a heart attack

Question 9

What is peripheral vascular disease?

Answer 9

• Narrowing of the arteries due to atherosclerosis of arteries other than those of the heart or brain
• The arteries to the legs are most commonly effected.
• Pain is experienced in the leg muscles due to limited supply of oxygen

Question 10

What is deep vein thrombosis? (DVT)

Answer 10

• A blood clot that forms in a deep vein, most commonly in the leg
• This can break off and result in a pulmonary embolism in the lungs

Question 11

What is cholesterol?

Answer 11

A type of lipid found in the cell membrane, it also used to make the sex hormones:
•testosterone
•oestrogen
•progesterone

Question 12

How is cholesterol synthesised?

Answer 12

• It’s synthesised by all cells

* 25% of total production takes place in the liver

Question 13

What’s the role of high density lipoprotein (HDL)?

Answer 13

HDL transports excess cholesterol from the body cells to the liver for elimination. This prevents accumulation of cholesterol in the blood.

Question 14

What’s the role of low density Lipoproteins? (LDL)

Answer 14

LDL transports cholesterol to body cells

Question 15

Describe LDL receptors, negative feedback control and atheroma formation

Answer 15

Most cells have LDL receptors that take LDL into the cell where it releases cholesterol, once a cell has sufficient cholesterol and negative feedback system inhibits the synthesis of new LDL receptors and LDL circulates in the blood with me deposit cholesterol in the arteries forming atheromas

Question 16

What’s the importance in ratios of HDL to LDL in maintaining health?

Answer 16

A higher ratio of HDL to LDL will result in lower blood cholesterol and a reduced chance of atherosclerosis

Question 17

What are the be if it’s of physical activity and a low fat diet?

Answer 17

Regular physical activity tends to raise the HDL levels

Dietary changes aim to release the levels of total fat in the diet and to replace saturated with unsaturated fats

Question 18

What causes an increase in cholesterol level in the blood?

Answer 18

A diet high in saturated fats or cholesterol

Question 19

How do prescribed medication reduce blood cholesterol?

Answer 19

Drugs such as statins reduce blood cholesterol by inhibiting the synthesis of cholesterol by liver cells