Cardiovascular Disease, Blood Glucose levels and Obesity

What is atherosclerosis?

the accumulation of fatty material (consisting mainly of cholesterol

What happens to the artery as the atheroma grows?

The artery hardens and loses its elasticity

What does atherosclerosis cause?

Various cardiovascular diseases (CVD)

What are the effects of Thrombosis in Arteries?

1. At herons can rupture damaging the endothelium.

2. This damage releases clotting factors that activate a cascade of reactions resulting in the conversion of prothrombin to its active form thrombin.

3. Thrombin causes molecules of the plasma protein fibrinogen to form threads of fibrin.

4. The threads of fibrin from a mesh network that clots the blood and seals the wound. This provides a scaffolding for scar tissue.

5. The formation of a clot is referred to as thrombosis.

What can happen if the thrombus breaks loose?

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

What is peripheral vascular disease?

The narrowing of the arteries due to atherosclerosis of arteries other than those of the heart or brain

What is most commonly effected in peripheral vascular disease?

The legs

What is Deep Vein Thrombosis (DVT)?

a blood clot that forms in a deep vein (usually in leg)

What is cholesterol?

type of lipid found in cell membrane

What is cholesterol used to make?

the sex hormones — testosterone, oestrogen and progesterone

What is cholesterol synthesised by?

All cells although 25% of total production takes place in the liver

What causes an increase in cholesterol levels?

A diet high in saturated fats or cholesterol

What does high density lipoproteins (HDL) do?

Transports excess cholesterol from the body cells to the liver for elimination

what does low density lipoprotein (LDL) do?

transports cholesterol to body cells

What happens when 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 forming atheromas

What does a higher ratio of HDL:LDL result in?

Lower blood cholesterol and a reduced chance of atherosclerosis

What drugs reduce cholesterol?

Statins which inhibit the synthesis of cholesterol by liver cells

What does chronic elevation of blood glucose lead to?

The endothelium cells taking in more glucose than normal, damaging blood vessels

What does the pancreatic receptors do?

Respond to raised glucose levels in the blood by increasing the secretion of insulin from the pancreas

What does glucagon do?

Activates the conversion of glycogen to glucose in the liver increasing blood glucose concentration

What happens to glucose levels during exercise?

Glucose levels are raised by adrenaline released from the adrenal glands

What does adrenaline do?

Stimulates glucagon secretion and inhibits insulin secretion

When does type 1 diabetes develop?

during childhood

What is type 1 diabetes?

When a person is unable to produce insulin, this can be treated with regular insulin injections

When does type 2 diabetes occur?

later in life

What is type 2 diabetes?

When a person CAN produce insulin but their cells are less sensitive to it. This resistance is linked to a decrease in the number of insulin receptors in the liver

What happens to glucose levels in a person with diabetes?

It rises rapidly after a meal

Why is urine used as an indicator for diabetes?

The kidneys will remove some of the glucose resulting in glucose appearing in urine.

What is used to test for diabetes?

Glucose tolerance test

What happens during a glucose tolerance test?

A person fasts, then is given a sugary drink and then their blood glucose concentration is measured for at least two hours

What is obesity?

excessive accumulation of body fat

What is obesity a major risk factor to?

cardiovascular disease and type 2 diabetes

What's the most common cause of obesity?

Excessive consumption of foods rich in fats and free sugars

How is BMI calculated?

weight in kg/height in meters squared

How high is a BMI before a person is considered obese?

30