Unit 2: Physiology & Health - Key Area 7: Pathology of Cardiovascular Disease

Question 1

What is atherosclerosis?

Answer 1

Atherosclerosis is the formation and build up of plaque underneath the endothelium of the artery wall.

Question 2

What are the plaques made of in atherosclerosis?

Answer 2

The plaques are made of fatty material (made up mainly of cholesterol but as the years go on, fibrous material and calcium also build up).

Question 3

What can the plaque that forms and builds up through atherosclerosis also be called?

Answer 3

An atheroma.

Question 4

What can an atheroma also lead to?

Answer 4

• Arteries becoming blocked/clogged and loses its elasticity.
• Reduced blood flow in the artery
• Reduced diameter of lumen of artery leading to increased blood pressure.

Question 5

What is atherosclerosis also called and why is this?

Answer 5

Atherosclerosis is sometimes called “hardening of the arteries” because the large plaques can become hardened by deposits of calcium.

Question 6

What cardiovascular diseases is atherosclerosis the cause of?

Answer 6

• Coronary heart disease (including angina)
• Strokes
• Heart attack’s
• Peripheral vascular disease

Question 7

If Atheromas on the lining inside an artery become enlarged what might happen?

Answer 7

If Atheromas on the lining inside an artery become enlarged they can burst through the endothelium and damage it. If this happens, clotting might occur.

Question 8

What is a thrombosis?

Answer 8

Thrombosis is the formation of a blood clot (thrombosis) in a vessel.

Question 9

What is blood clotting primarily?

Answer 9

Blood clotting is a protective reaction which is triggered by damage to cells.

Question 10

What is the series of reactions that occur when clotting factors are released?

Answer 10

Prothrombin (the inactive enzyme) is converted into thrombin (the active enzyme) by clotting factors. The thrombin then causes the conversion of fibrinogen into threads of fibrin. The threads of fibrin form a mesh network that traps blood platelets and blood cells creating a clot.

Question 11

If the blood clot becomes break loose/dislodged and becomes mobile what may form?

Answer 11

An embolus.

Question 12

What can an embolus do?

Answer 12

An embolus is carried in the blood until it reaches a narrow vessel, where it blocks the vessel and causes blood flow to be severely restricted or even stop it completely.

Question 13

Blockage of a coronary artery by a thrombus such as an embolus is also called?

Answer 13

A coronary thrombus

Question 14

What can be the result of a coronary thrombus?

Answer 14

It stops oxygen from getting to the heart muscle and can lead to a myocardial infarction (MI) also known as a heart attack.

Question 15

A thrombus that causes a blockage in an artery to the brain may lead to a?

Answer 15

Stroke.

Question 16

How can strokes be damaging to tissue?

Answer 16

If the cells do not have a supply of oxygen, this leads to the death of tissue.

Question 17

What is prothrombin?

Answer 17

An inactive enzyme.

Question 18

What is thrombin?

Answer 18

An active enzyme.

Question 19

Is fibrinogen insoluble?

Answer 19

Yes

Question 20

Is fibrin insoluble?

Answer 20

No it is soluble.

Question 21

What are the peripheral arteries?

Answer 21

The peripheral arteries are any arteries apart from those of the heart or the brain.

Question 22

What happens when any of the peripheral arteries are affected by atherosclerosis?

Answer 22

Their central cavity becomes narrower, which leads to peripheral vascular disease.

Question 23

What arteries does peripheral vascular disease normally affect?

Answer 23

Arteries in the legs.

Question 24

When blood vessels have a blockage due to peripheral vascular disease what is normally felt and why is this?

Answer 24

Blood flow is restricted and pain is felt in the muscles because they are not receiving enough oxygen.

Question 25

What is an example of a peripheral vascular disease, why is this caused and what does this cause?

Answer 25

Deep vein thrombosis (DVT), which is the formation of a thrombus in a vein, most commonly in the lower leg. This causes pain and swelling and veins close to the surface become swollen with blood.

Question 26

If a DVT breaks loose what can it result in?

Answer 26

A pulmonary embolism.

Question 27

How does a pulmonary embolism work?

Answer 27

The clot is transported to the heart by the Vena Cava where it can then block the pulmonary artery and cause a pulmonary embolism.

Question 28

What is the role of the enzyme thrombin in blood clotting?

Answer 28

Promotes the conversion of fibrinogen (insoluble) into fibrin which is soluble and will help/cause clott.

Question 29

What is the heart not getting a supply of during a heart attack?

Answer 29

Oxygen and as it is a muscle it can no longer respire to produce energy needed for it to contract so no/little blood is pumped around the body.

Question 30

What is the treatment for a pulmonary embolism?

Answer 30

Anticoagulant

Question 31

What is cholesterol?

Answer 31

Cholesterol is a type of lipid required by the body.

Question 32

Why is cholesterol required by the body?

Answer 32

• It is a component of every cell membrane.

- it is required to make the sex hormones - testosterone, oestrogen and progesterone.

Question 33

What is cholesterol made by?

Answer 33

Cholesterol is made by all cells, although 25% of total cholesterol is produced in the liver.

Question 34

How is blood cholesterol raised?

Answer 34

By a diet high in saturated fat or cholesterol.

Question 35

What are lipoproteins?

Answer 35

Molecules consisting of lipids and proteins.

Question 36

Where are lipoproteins present and what do they do?

Answer 36

In blood plasma and transport lipids from one part of the body to another.

Question 37

What are the two types of lipoproteins?

Answer 37

Low-density lipoproteins (LDLs) and High density lipoproteins (HDLs).

Question 38

What is cholesterol transported to body cells by?

Answer 38

LDLs

Question 39

What do LDL receptors do?

Answer 39

LDL receptors which are present in most cell take LDLs into the cell where it releases the cholesterol.

Question 40

How does the negative feedback of LDLs work and what can this cause?

Answer 40

There is a negative feedback effect whereby a high concentration of cholesterol in the cell inhibits synthesis of new LDL receptors. LDL therefore circulates in the blood instead where it may deposit cholesterol in the arteries forming atheromas.

Question 41

Is LDL bad or good for us?

Answer 41

Bad we should aim to lower LDLs in the diet.

Question 42

What do HDLs do?

Answer 42

HDLs transport excess cholesterol from the body cells to the liver for elimination.

Question 43

Are HDLs good for us?

Answer 43

Yes as they reduce levels of cholesterols in the blood.

Question 44

What are some ways of reducing cholesterol levels?

Answer 44

• Undertake regular physical activity in order to raise HDL levels
• Dietary changes to reduce the total fat intake and to replace saturated fats with unsaturated fats, which helps to maintain a healthy HDL:LDL ratio.
• If necessary prescription drugs such as statins can be taken which reduce blood cholesterol by inhibiting the synthesis of cholesterol by liver cells.

Question 45

What are lipoproteins?

Answer 45

Molecules containing lipids and proteins.

Question 46

Where in the blood is most cholesterol produced?

Answer 46

The liver

Question 47

Why are LDLs known as “bad cholesterol”?

Answer 47

They can cause atheromas.

Question 48

What type of drugs can be prescribed to lower cholesterol levels?

Answer 48

Statins

Question 49

How does the negative feedback of LDLs work?

Answer 49

• Cell has adequate supply of cholesterol.
• Synthesis of new LDL receptors is inhibited.
• Less LDL is absorbed by cells
• LDL - cholesterol is taken up by endothelial cells lining the inside of an artery.
• Cholesterol is deposited in an atheroma in the wall of the artery.