5.3 Heart Disease Flashcards
What is an atheroma?
A fatty deposit that forms within the wall of an artery.
How does an atheroma begin?
As fatty streaks that are accumulations of white blood cells that have taken up Low-Density Lipoproteins
What is atheromatous plaque made up of?
- Cholesterol
- Fibres
- Dead muscle cells.
Where does atheromatous plaque most regularly occur?
In larger arteries
How do they cause the flow of blood to narrow?
They bulge into the lumen of the artery
What two conditions do atheromas increase the risk of?
- Thrombosis
- Aneurysm
What is a thrombus?
A blood clot
What is the condition called when you have a thrombus?
Thrombosis
What happens when the wall of an artery is weakened from an atheroma?
The weakened points swell to form a balloon-like, blood-filled structure, called an aneurysm.
What happens when an aneurysm bursts?
Haemorrhaging and loss of blood to the region of the body served by that artery.
What is a myocardial infarction?
A reduced supply of oxygen to the muscle of the heart.
What are the four main risk factors of getting CHD?
- Smoking
- High Blood
- Pressure
- Blood Cholesterol
- Diet
What is the single most effective way of increasing life expectancy?
Stopping smoking
What are the two constituents of tobacco smoke that increase the likelihood of heart disease?
- Carbon Monoxide
- Nicotine
How does Carbon Monoxide increase the risk of heart disease?
It combines irreversibly with haemoglobin to form carboxyhaemoglobin.
How does the formation of carboxyhaemoglobin affect the body?
Because it reduces the oxygen-carrying capacity of the blood, causing the heart to work harder, leading to raised bloody pressure.
How does the intake of nicotine increase the risk of heart disease?
Nicotine stimulates the production of adrenaline, which raises heart rate and pressure.
How does nicotine affect red blood cells?
It makes them more sticky & therefore leads to a higher risk of thrombosis and myocardial infarction.
What are the 3 reasons high blood pressure increases risk of heart disease?
- The heart is working harder and is therefore more prone to failure.
- Higher blood pressure in the arteries means they are more likely to develop an aneurysm & burst.
- To resist the higher pressure, the walls of the arteries may thicken and harden, restricting blood flow.
What are the two types of lipoproteins?
- High-density lipoproteins
- Low-density lipoproteins
What type of lipoprotein increases risk of heart disease?
Low-density lipoproteins
How do LDLs increase risk of heart disease?
They transport cholesterol from the liver to the tissues, infiltrating artery walls, leading to the development of atheroma and hence heart disease.
What two diet-related aspects increase risk of heart disease?
- High levels of salt
- High levels of saturated fat
How do high levels of salt increase risk of heart disease?
Raise blood pressure
