Unit 2.7 - Cardiovascular Disease Flashcards
What is atherosclerosis?
The accumulation of fatty material consisting mainly of cholesterol, fibrous material and calcium forming an atheroma or plaque beneath the endothelium
How does atherosclerosis effect arteries and blood pressure?
As they Atheroma grows the artery thickens and loses its elasticity. The diameter of the lumen becomes reduced and bloodflow becomes restricted resulting in increased blood pressure
What is arthrosclerosis of the root cause of?
Various cardiovascular diseases
What happens when atheroma ruptures?
- Rupture damages endothelium
- Damage releases clotting factors that activate a cascade of reactions resulting in the conversion of the enzyme prothrombin to its active form thrombin t
What does thrombin cause?
Thrombin causes molecules of the plasma protein fibrinogen to form threads of fibrin
The fibrin threads form a meshwork that clots the blood, seals the wound and provides a scaffold for the formation of scar tissue
The formation of a clot (thrombus) is referred to as thrombosis
What happens if a thrombin breaks loose?
It forms an embolus which travels through the bloodstream until it block a blood vessel
What can a thrombus in an artery in the brain lead to?
- Lead to a stroke
* Cells are deprived of oxygen leading to death of tissue
What can a thrombosis in a coronary artery lead to?
A myocardial infarction (MI) commonly known as a heart attack
What is peripheral vascular disease?
- Narrowing of the arteries due to atherosclerosis of arteries other than those of the heart or brain
- The arteries to the legs are most commonly effected.
- Pain is experienced in the leg muscles due to limited supply of oxygen
What is deep vein thrombosis? (DVT)
- A blood clot that forms in a deep vein, most commonly in the leg
- This can break off and result in a pulmonary embolism in the lungs
What is cholesterol?
A type of lipid found in the cell membrane, it also used to make the sex hormones:
•testosterone
•oestrogen
•progesterone
How is cholesterol synthesised?
- It’s synthesised by all cells
* 25% of total production takes place in the liver
What’s the role of high density lipoprotein (HDL)?
HDL transports excess cholesterol from the body cells to the liver for elimination. This prevents accumulation of cholesterol in the blood.
What’s the role of low density Lipoproteins? (LDL)
LDL transports cholesterol to body cells
Describe LDL receptors, negative feedback control and atheroma formation
Most cells have LDL receptors that take LDL into the cell where it releases cholesterol, once a cell has sufficient cholesterol and negative feedback system inhibits the synthesis of new LDL receptors and LDL circulates in the blood with me deposit cholesterol in the arteries forming atheromas