Control Of Cholesterol Flashcards
What is cholesterol?
Cholesterol is a type of lipid found in the cell membrane
What can cholesterol be used to make?
Sex hormones such as testosterone, oestrogen and progesterone
What cells synthesis cholesterol?
All cells
How much cholesterol is produced in the liver?
25% of all cholesterol is produced in the liver
What kind of diet leads to an increase in cholesterol levels?
A diet high in saturated fats or cholesterol leads to increased cholesterol levels in the blood
What are the two types of cholesterol?
High density lipoprotein ( HDL ) good cholesterol
Low density lipoprotein ( LDL ) bad cholesterol
What does high density lipoprotein do?
High density lipoprotein transports excess cholesterol from the body cells to the liver for elimination
Why does high density lipoprotein transport excess cholesterol to the liver?
For elimination to prevent accumulation of cholesterol in the blood
What does low density lipoprotein do?
Low density lipoprotein transports cholesterol to body cells as most cells have LDL receptors that take LDL into the cell where it releases cholesterol.
Describe the negative feedback system of cholesterol.
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.
What will a high ratio of HDL to LDL cause
Lower blood level cholesterol and a reduced chance of atherosclerosis
What can raise high density lipoprotein ( HDL ) levels?
Regular physical activity
What are the three ways to reduce blood cholesterol?
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.
What can chronic elevation of blood glucose cause?
Endothelium cells taking in more glucose than normal, damaging the blood vessels.
What does an increase in blood glucose or cholesterol cause?
Atherosclerosis, which may cause cardiovascular disease, stroke, or peripheral vascular disease
What happens to smaller blood vessels as a result of elevated blood glucose?
They may be damaged and this can result in haemorrhaging of blood vessels in the retina, renal failure or peripheral nerve dysfunction
How do pancreatic receptors respond to raised blood glucose?
Pancreatic receptors respond by increasing the secretion of insulin from the pancreas
What does insulin do?
Insulin converts glucose to glycogen, lowering blood glucose levels.
How do pancreatic receptors respond to low blood glucose levels?
Pancreatic receptors stimulate the secretion of glucagon from the pancreas.
What does glucagon do?
Glucagon activates the conversion of glycogen to glucose in the liver, raising blood glucose levels .
What organs are involved in the control of blood glucose?
The liver and pancreas
What happens during flight or fight responses?
Glucose concentrations in the blood are raised by adrenaline, which is released from adrenal glands, stimulating glucagon secretion and inhibiting insulin secretion.
What gland produces adrenaline?
The adrenal gland
