Topic 1 - Blood Clotting And Atherosclerosis Flashcards
What is coronary heart disease (CHD)
When the coronary arteries supplying the heart become blocked, cutting off oxygen and glucose
What can CHD cause
A section of the heart muscle to die
What is angina
When coronary arteries become partially blocked, causing heart to respire anaerobicly, produces lactic acid
What is Thrombosis
Formation of blood clot inside vessel, obstructing flow
What is death of areas of cardiac muscle referred to as?
A heart attack
What usually causes heart attacks or strokes
Atherosclerosis
What is the inner lining of an artery called
The endothelium
What does a healthy endothelium do
Prevents toxins from penetrating the smooth muscle of a blood vessel
What happens when the endothelium gets damaged (endothelium dysfunction)
Lipids and toxins enter smooth muscle cells
Endothelium has been disrupted
What are the four stages leading from disrupter to positive feedback?
1) inflammatory response
2) calcium salts and fibrous tissue build up
3) plaque causes endothelium to tear
4. Narrowing caused by plaque narrows vessel
What is an inflammatory response?
This accumulate cholesterol from the blood
What is the mound of fat-laden cells called
An atheroma
What does the atheroma do?
Causes calcium salts and fibrous tissue to build up in area, producing plaque
What happens as the plaque grows
It bulges into lumen of artery, causing a reduction of elasticity
What is a reduction of elasticity known as?
Atherosclerosis
Hardening of the arteries
How can a large plague cause a thrombus?
Exposes underlying cells to blood
Why does a plaque raise blood pressure
Narrows arteries, making it harder to pump blood around the body
How is a high blood pressure an example of positive feedback?
Higher blood pressure in turn will make new plaques more likely, thus increasing blood pressure further
What causes the blood clotting processes to begin
Direct contact between blood and collagen (in artery wall)
What two things catalyse the conversion of pro thrombin to thrombin?
Thromboplastin + calcium ions
What is Thromboplastin
Released by platelets
Where does the calcium come from
In blood plasma
What is prothrombin
Plasma protein
What’s thrombin
Converts fibrinogen to fibrin threads
