Unit 2-Pathology Of Cardiovascular Disease (CVD) Flashcards
What is atherosclerosis?
Atherosclerosis is the build-up of fatty material (such as cholesterol, fibrous material and calcium)
What can the plaque that forms and builds up through atherosclerosis also be called?
An atheroma.
What can an atheroma cause?
Arteries can lose its elasticity.
Reduced blood flow in the artery
Reduced diameter of lumen of artery leading to increased blood pressure.
What cardiovascular diseases can atherosclerosis lead to?
Coronary heart disease (including angina)
Stroke
Heart attack
Peripheral vascular disease
If atheromas on the lining inside an artery become enlarged, what might happen?
They can burst through the endothelium and damage it.
If this happens, clotting might occur.
What is thrombosis?
Formation of a blood clot (thrombosis) in a vessel.
What is the series of reactions that occur when clotting factors are released?
Prothrombin (the inactive enzyme) is converted into thrombin (the active enzyme) by clotting factors.
The thrombin then causes the conversion of fibrinogen into threads of fibrin.
The threads of fibrin form a mesh network that traps blood platelets and blood cells creating a clot.
If the blood clot becomes break loose/dislodged and becomes mobile what may form?
An embolus.
What can an embolus do?
An embolus is carried in the blood until it reaches a narrow vessel, where it blocks the vessel and causes blood flow to be severely restricted or even stop it completely.
Blockage of a coronary artery by a thrombus such as an embolus is also called?
A coronary thrombus
What can be the result of a coronary thrombus?
Can lead to a myocardial infarction (MI) also known as a heart attack when it stops oxygen from reaching the heart.
A thrombus that causes a blockage in an artery to the brain may lead to a?
Stroke.
How can strokes be damaging to the tissue?
If the cells do not have a supply of oxygen, this leads to the death of tissue.
What is prothrombin?
An inactive enzyme.
What is thrombin?
An active enzyme.
What are the peripheral arteries?
The peripheral arteries are any arteries apart from those of the heart or the brain.
What happens when any of the peripheral arteries are affected by atherosclerosis?
Their central cavity becomes narrower, which leads to peripheral vascular disease.
What arteries does peripheral vascular disease commonly affect?
Arteries in the legs.
When blood vessels have a blockage, what is normally felt and why is this?
Blood flow is restricted and pain is felt in the muscles because they are not receiving enough oxygen.
What is an example of a peripheral vascular disease, why is this caused and what does this cause?
Deep vein thrombosis (DVT), which is the formation of a thrombus in a vein, most commonly in the lower leg.
This causes pain and swelling and veins close to the surface become swollen with blood.
If a DVT breaks loose, what can it result in?
A pulmonary embolism.
Describe the path dislodges DVT takes to cause a pulmonary embolism.
The clot is transported to the heart by the Vena Cava, through the right atrium and ventricle to the pulmonary artery where it can then block it.
What is the role of the enzyme thrombin in blood clotting?
Thrombin causes the plasma protein fibrinogen to form threads of fibrin.
Fibrin threads mesh together clotting the blood.
What is the treatment for a pulmonary embolism?
Anticoagulant
What is cholesterol?
Cholesterol is a type of lipid required by the body.
Why is cholesterol required by the body?
- It is a component of every cell membrane.
- it is required to make the sex hormones - testosterone, oestrogen and progesterone.
What is cholesterol made by?
Cholesterol is made by all cells, although 25% of total cholesterol is produced in the liver.
How is blood cholesterol raised?
By a diet high in saturated fat or cholesterol.
What are lipoproteins?
Molecules consisting of lipids and proteins.
Where are lipoproteins present?
What do they do?
In blood plasma.
Transport lipids from one part of the body to another.
What are the two types of lipoproteins?
Low-density lipoproteins (LDLs) and High density lipoproteins (HDLs).
Which lipoproteins transport cholesterol to body cells?
Low-density lipoproteins (LDLs)
Why do cells have LDL receptors on their surface?
Receptors allow cholesterol to be deposited inside the cells by LDLs
How does the negative feedback of LDLs work?
High concentration of cholesterol in the cell inhibits the synthesis of new LDL receptors and therefore reduced how much cholesterol is absorbed into the cells.
What happens to the excess LDL carried cholesterol?
Circulates in the blood where it may deposit cholesterol in the arteries forming atheromas.
What do HDLs do?
HDLs transport excess cholesterol from the body cells to the liver for elimination.
Which of the following will result in lower blood cholesterol levels and reduce chances of developing atherosclerosis?
higher ratio of HDL to LDL
or
lower ratio of HDL to LDL
A higher ratio of HDL to LDL will result in lower blood cholesterol levels and will reduce the chances of developing atherosclerosis.
What are some ways of reducing cholesterol levels?
Regular physical activity can raise HDL levels
Diet low in saturated fats can raise HDL levels
Medication such as statins inhibit the synthesis of cholesterol in the liver
