2.7 Flashcards
(25 cards)
What is atherosclerosis?
the accumulation of fatty substances underneath the endothelium in the arteries.
Break down the process of atherosclerosis
High levels of fats and cholesterols build up and stay in the blood, these substances can deposit underneath the endothelium of arteries, creating plaques (atheromas). These can narrow the lumen of arteries and make the artery stiff, preventing blood flow and increasing blood pressure.
What happens as an atheroma grows?
the artery thickens and loses its elasticity. Additionally, there is a significant reduction in the diameter of the affected artery’s lumen.
How does atherosclerosis affect blood pressure?
causes an increase in blood pressure
Give 4 cardiovascular health conditions caused by atherosclerosis
angina
stroke
myocardial infarction (heart attack)
peripheral vascular disease
What is produced if the endothelial wall of an artery breaks as a result of atherosclerosis?
a thrombus
The process of blood clotting
prothombin - thrombin
^ clotting factors
fibrinogen - fibrin
^ insoluble mesh work
In words, break down the formation of a thrombus (5 stages)
Stage 1 - There is damage to blood vessel endothelium and clotting factors are released
Stage 2 - Clotting factors convert inactive prothrombin into the active enzyme thrombin
Stage 3 - Thrombin stimulates plasma protein fibrinogen to fibrin
Stage 4 - Fibrin threads form a mesh work to which platelets adhere
Stage 5 - This creates a clot
What is a thrombus?
a blood clot that forms inside a blood vessel
What is an embolus?
a thrombus that travels in the blood stream
What is a myocardial infarction(also known as a heart attack)?
occurs when a blood clot blocks a coronary artery, blocking flow of blood to the cardiac muscle. This lack of blood flow can cause death of myocardial tissue due to lack of oxygen and nutrients.
What is a stroke?
occurs whena blood clot blocks an artery supplying the brain. This lack of blood can cause death of brain tissue due to lack of oxygen and nutrients.
What is peripheral vascular disease?
occurs when arteries in the peripheries of the body narrow as a result of atherosclerosis. This typically occurs in the legs, where pain can be felt as a result of lack of oxygen to the muscle cells.
What is a deep vein thrombosis?
a thrombus that occurs in a deep vein in the leg. This can cause leg swelling and reduced blood flow from the leg.
What is a pulmonary embolism?
occurs when a blood clot from elsewhere in the body travels through the heart, towards the lungs, and blocks an artery that brings blood to the lungs.
What are the symptoms of a pulmonary embolism?
chest pains
breathing difficulties
palpitations
What is cholesterol and what is it used for in the body?
a type of lipid that is used in cell membranes and to form sex hormones, such as oestrogen, progesterone and testosterone.
Where is cholesterol synthesised?
is synthesised by all cellls, but 25% of total cholesterol production occurs in the liver.
What causes an increased cholesterol level in the blood?
a diet high in saturated fats and cholesterol
What is HDL and what is its role?
High-density lipoprotein is a molecule that transports cholesterol to the liver from body cells to be broken down.
What is LDL and what is its role?
Low-density lipoprotein is a molecule that transports cholesterol from the liver to the body cells.
Describe how the body regulates cholesterol levels
LDL receptors exist on cells, allowing cholesterol to be depositied by LDL. As cholesterol inside the cell increases, the number of LDL receptors decreses as cholesterol requirement decreases. Due to this, excess LDL remains in the blood and deposits cholesterol in the linings of arteries, contributing to atheroma formation.
What is the benefit of having a higher ratio of HDL to LDL?
having a higher ratio of HDL to LDL decreases risk of cardiovascular disease
How can you lower blood cholesterol with diet?
reduce the amount of fat in the diet
