Pathology of Cardiovascular Disease

Question 1

What are some of the main processes leading to Cardiovascular disease ?

Answer 1

Atherosclerosis and Hypertension

Question 2

What is cardiovascular disease ?

Answer 2

Cardiovascular disease is a group of diseases that affect the heart and blood vessels

Question 3

What are examples of cardiovascular disease ?

Answer 3

Peripheral Vascular Disease (PVD)
Angina
Myocardial infarction (heart attack)
Stroke

Question 4

What is the root cause of various cardiovascular diseases ?

Answer 4

Atherosclerosis

Question 5

What is atherosclerosis ?

Answer 5

The accumulation of fatty material beneath the endothelium of an artery resulting in the formation of an atheroma (or plaque)

Question 6

What is an atheroma ?

Answer 6

Fatty material consisting of mainly cholesterol, fibrous material and calcium.
-As the atheroma grows, the walls of the artery thicken and lose elasticity.
-Diameter of the lumen narrows and blood flow becomes restricted.
-Results in an increased blood pressure.

Question 7

What is a thrombus and thrombosis ?

Answer 7

A thrombus is a blood clot and thrombosis is the process by which a clot is created.

Question 8

Describe the cascade of reactions that take place during the process of thrombosis

Answer 8

1) Atheromas rupture and damage the endothelium.
2) Results in the release of clotting factors.
3) Clotting factors convert prothrombin enzyme into its active form thrombin.
4) Thrombin turns soluble protein fibrinogen into insoluble protein fibrin threads.
5) Fibrin threads form a meshwork that clots the blood forming a thrombus.
6) Thrombus seals the wound and provides a scaffold for formation of scar tissue.

Question 9

What is an embolus and an embolism ?

Answer 9

An embolus is a loose blood clot (thrombus) and an embolism is when an embolus gets lodged and blocked a blood vessel.

Question 10

How does an atheroma lead to the formation of a blood clot or thrombus ?

Answer 10

-An atheroma may rupture and damage the endothelium which results in the release of clotting factors.
-Clotting factors activates a cascade of reaction that lead to the formation of a blood clot or thrombus.

Question 11

Explain how a thrombosis could effect the tissues of the body

Answer 11

In some cases, a thrombus may break loose, forming an embolus.
1) Embolus travels through the bloodstream and block a blood vessel.
2) Deprives cells of oxygen and leads to the death of tissues.
-If this blockage occurs in the coronary artery, leads to a myocardial infarction.
-If this blockage occurs in an artery of the brain, leads to a stroke.

Question 12

What are peripheral arteries ?

Answer 12

Peripheral arteries are arteries not connected to the heart or brain.

Question 13

What is peripheral vascular disease (PVD) ?

Answer 13

-Narrowing of the arteries, due to atherosclerosis, that are not connected to the heart or brain.
-Arteries to the legs are most commonly affected.
-Pain is experienced in the leg muscles due to a limited supply of oxygen.

Question 14

What is DVT

Answer 14

Deep Vein Thrombosis (a type of PVD)
-Formation of a thrombus in a deep vein of the leg.
-Thrombus may break off and result in a pulmonary embolism in the lungs (leads to chest pain, difficulty breathing, sudden death)

Question 15

Describe the role of cholesterol within cells

Answer 15

-Required as a structural component of the cell membrane
-Required to synthesize sex hormones testosterone, oestrogen and progesterone.

Question 16

Where in the body is cholesterol synthesized

Answer 16

-Cholesterol is a lipid molecule synthesized by all human cells.
-25% of total cholesterol production takes place in the liver.

Question 17

What are lipoproteins ?

Answer 17

Lipoproteins are carrier proteins found in the blood plasma - their role is to carry cholesterol and other lipids around the body.
There are two types High Density Lipoproteins (HDLs) and Low Density Lipoproteins (LDLs)

Question 18

Describe role of High Density Lipoproteins in transporting cholesterol around the body.

Answer 18

-Transport excess cholesterol from the body cells to the liver for elimination.
-Prevents the accumulation of cholesterol in the blood.
- HDL molecules reduce the risk of atherosclerosis.

Question 19

Describe role of Low Density Lipoproteins in transporting cholesterol around the body.

Answer 19

-Transport cholesterol from the liver to the body cells for use within the cell.
-Circulation of LDL in the blood may cause cholesterol to be deposited in the arteries forming atheromas.
-LDL molecules increase the risk of atherosclerosis.

Question 20

Describe how the uptake of cholesterol by body cells is regulated.

Answer 20

-Most body cells have LDL receptors on the surface of their cell membranes.
-These receptors allow cells to take in LDL where it releases cholesterol.
-Once a cell has sufficient cholesterol, a negative feedback system inhibits the synthesis of new LDL receptors preventing further uptake of cholesterol.
-LDL circulates in the blood where it may deposit cholesterol in the arteries forming atheromas.

Question 21

Why is having a higher HDL:LDL ratio important for our health ?

Answer 21

1) Reduces blood cholesterol levels
2) Reduces risk of atherosclerosis

Question 22

How could you increase your HDL levels ?

Answer 22

1. Follow a diet low in saturated fats
2. Perform regular physical activity

Question 23

Describe how drugs such as statins reduce cholesterol levels ?

Answer 23

Statins reduce blood cholesterol levels by inhibiting the synthesis of cholesterol by Liver cells

Question 24

Compare the glucose concentrations of the plasma of normal people with that of someone with untreated diabetes

Answer 24

Normal = 5mmol/L

Untreated diabetes = 10 - as high as 30mmol/L

Question 25

What is macrovascular disease ?

Answer 25

Chronic elevation of blood glucose leads to the endothelial cells taking in more glucose than normal, damaging the blood vessels. Damage to the blood vessels may cause atherosclerosis to develop which leads to CVD, stroke or peripheral vascular disease.

Question 26

Identify 3 symptoms an individual may experience as a result of microvascular disease.

Answer 26

1) Haemorrhage of blood vessels in retina 2) Renal failure 3) Peripheral nerve dysfunction

Question 27

How much glucose can the liver store ?

Answer 27

The liver can store up to 100g of glucose in the form of glycogen

Question 28

Name the two hormones released from the pancreas that help regulate blood glucose levels.

Answer 28

1) Insulin 2) Glucagon

Question 29

Describe the body reacts to decreased blood glucose levels.

Answer 29

1) Pancreatic receptors respond to decreased blood glucose levels 2) Pancreas increases secretion of Glucagon 3) Glucagon activates the conversion of glycogen to glucose in the Liver 4) Allows blood glucose levels to increase and return to normal

Question 30

Describe the body reacts to increased blood glucose levels.

Answer 30

1) Pancreatic receptors respond to increased blood glucose levels 2) Pancreas increases secretion of Insulin 3) Insulin activates the conversion of glucose to glycogen in the Liver 4) Allows blood glucose levels to decrease and return to normal

Question 31

Why do our body cells need glucose?

Answer 31

For the process of cellular respiration

Question 32

Describe the role of the adrenal gland during and after exercise

Answer 32

During exercise and flight or flight responses, the adrenal glands release a hormone called adrenaline Adrenaline increases blood glucose concentrations by: 2) Stimulating glucagon secretions. 2) Inhibiting insulin secretions.

Question 33

What are the two types of diabetes ?

Answer 33

Type 1 and Type 2

Question 34

What are differences between type 1 and type 2 diabetes

Answer 34

Stage of life when the condition first occurs: Type 1 = child hood Type 2 = adulthood, risk increased by being overweight or obese Ability of pancreatic cells to produce insulin: Type 1 = absent Type 2 = present, Liver cells less receptive to insulin's action as lower number of insulin receptors Treatment: Type 1 = Regular doses on insulin Type 2 = Exercise and diet control

Question 35

Name the disease that impacts the body’s ability to control its blood glucose levels.

Answer 35

Diabetes

Question 36

Identify the characteristic associated with type 2 diabetes

Answer 36

-Typically develops later in life (adulthood) -Risk increased by being overweight -Individuals able to produce Insulin but their cells are less sensitive to it, linked to decreased number of insulin receptors in the Liver -Leads to failure to convert glucose to glycogen

Question 37

Identify the characteristics associated with Type 1 diabetes.

Answer 37

-Usually occurs in childhood -Individuals unable to produce Insulin -Treated with regular doses of Insulin

Question 38

What are problems with both types of diabetes

Answer 38

-Blood glucose concentrations will rise rapidly after a meal in both types (kidneys will remove some of this glucose, leading to glucose appearing in urine)

Question 39

What test could be used to indicate if a person suffers from diabetes?

Answer 39

The appearance of glucose in urine

Question 40

How do the results of a glucose tolerance test identify if an individual diabetic?

Answer 40

A diabetic’s blood glucose level starts at a higher level, increases to a much higher level and takes longer to return to its starting concentration compared, to a non-diabetic

Question 41

Describe how a glucose tolerance test is used to diagnose an individual with diabetes.

Answer 41

-Blood glucose concentration of the individual are initially measured after fasting -The individual then drinks a glucose solution -Changes in their blood glucose concentration are measured for at least two hours

Question 42

What is glucose tolerance and a glucose tolerance test ?

Answer 42

Glucose tolerance is the capacity of the body to cope with ingested glucose by produce correct levels of insulin. A glucose tolerance test is a test used to diagnose an individual with diabetes.

Question 43

What is obesity

Answer 43

Characterised by excess body fat in relation to lean tissue such as muscle. -Is linked to high fat diets and a decrease in physical activity.

Question 44

How might obesity impair our health?

Answer 44

1) Major risk factor for CVD 2) Major risk factor for Type 2 Diabetes

Question 45

How could an individual change their activity to reduce levels of obesity?

Answer 45

Physical activity increases energy expenditure and preserves lean tissue such as muscle - Helps to reduce risk of CVD by keeping weight under control, minimising stress, reducing hypertension and improving blood lipid profiles

Question 46

How could an individual change their diet to reduce levels of obesity?

Answer 46

1) Energy intake in the diet should limit fats since they have a high calorific value per gram 2) Energy intake in the in the diet should limit free sugars since they require no metabolic energy to be expended in their digestion

Question 47

What is BMI

Answer 47

Body Mass Index, a calculation based on the idea that every person has an ideal body mass. -Commonly used to measure obesity but it can wrongly classify muscular individuals as obese.

Question 48

How do you calculate an individual’s BMI?

Answer 48

BMI Formula: BMI=weight (kg)/height (m)2

Question 49

Which BMI value would classify an individual as obese?

Answer 49

A BMI value of 30 or above

Question 50

Why might a BMI calculation wrongly classify a muscular individual as obese?

Answer 50

BMI calculations do not differentiate between levels of fat and lean body tissue such as muscle.