Control Of Cholesterol

Question 1

What is cholesterol?

Answer 1

Cholesterol is a type of lipid found in the cell membrane

Question 2

What can cholesterol be used to make?

Answer 2

Sex hormones such as testosterone, oestrogen and progesterone

Question 3

What cells synthesis cholesterol?

Answer 3

All cells

Question 4

How much cholesterol is produced in the liver?

Answer 4

25% of all cholesterol is produced in the liver

Question 5

What kind of diet leads to an increase in cholesterol levels?

Answer 5

A diet high in saturated fats or cholesterol leads to increased cholesterol levels in the blood

Question 6

What are the two types of cholesterol?

Answer 6

High density lipoprotein ( HDL ) good cholesterol
Low density lipoprotein ( LDL ) bad cholesterol

Question 7

What does high density lipoprotein do?

Answer 7

High density lipoprotein transports excess cholesterol from the body cells to the liver for elimination

Question 8

Why does high density lipoprotein transport excess cholesterol to the liver?

Answer 8

For elimination to prevent accumulation of cholesterol in the blood

Question 9

What does low density lipoprotein do?

Answer 9

Low density lipoprotein transports cholesterol to body cells as most cells have LDL receptors that take LDL into the cell where it releases cholesterol.

Question 10

Describe the negative feedback system of cholesterol.

Answer 10

Once a cell has sufficient cholesterol a negative feedback system inhibits the synthesis of new LDL receptors and LDL circulates in the blood where it may deposit cholesterol in the arteries, this is bad as it forms atheromas.

Question 11

What will a high ratio of HDL to LDL cause

Answer 11

Lower blood level cholesterol and a reduced chance of atherosclerosis

Question 12

What can raise high density lipoprotein ( HDL ) levels?

Answer 12

Regular physical activity

Question 13

What are the three ways to reduce blood cholesterol?

Answer 13

Regular physical activity
Dietary changes - unsaturated fats instead of saturated fats -
Using medicine such as statins to inhibit the synthesis of cholesterol in the liver.

Question 14

What can chronic elevation of blood glucose cause?

Answer 14

Endothelium cells taking in more glucose than normal, damaging the blood vessels.

Question 15

What does an increase in blood glucose or cholesterol cause?

Answer 15

Atherosclerosis, which may cause cardiovascular disease, stroke, or peripheral vascular disease

Question 16

What happens to smaller blood vessels as a result of elevated blood glucose?

Answer 16

They may be damaged and this can result in haemorrhaging of blood vessels in the retina, renal failure or peripheral nerve dysfunction

Question 17

How do pancreatic receptors respond to raised blood glucose?

Answer 17

Pancreatic receptors respond by increasing the secretion of insulin from the pancreas

Question 18

What does insulin do?

Answer 18

Insulin converts glucose to glycogen, lowering blood glucose levels.

Question 19

How do pancreatic receptors respond to low blood glucose levels?

Answer 19

Pancreatic receptors stimulate the secretion of glucagon from the pancreas.

Question 20

What does glucagon do?

Answer 20

Glucagon activates the conversion of glycogen to glucose in the liver, raising blood glucose levels .

Question 21

What organs are involved in the control of blood glucose?

Answer 21

The liver and pancreas

Question 22

What happens during flight or fight responses?

Answer 22

Glucose concentrations in the blood are raised by adrenaline, which is released from adrenal glands, stimulating glucagon secretion and inhibiting insulin secretion.

Question 23

What gland produces adrenaline?

Answer 23

The adrenal gland