The heart and blood vessels Flashcards
What is the function of pacemakers
Pacemakers control the speed and regularity of the heart beat by regulating contractions of the heart
Describe how deoxygenated blood travels through the heart
- Deoxygenated blood travels to the right atrium via the vena cava
- The right atrium contracts and pushes the blood down to the right ventricle
- the right ventricle contracts and pushes the blood to the lungs (via the pulmonary artery) to be oxygenated
Where are pacemaker cells found?
In the right atrium
What are stents
Stents are expandable tubes that are placed inside the coronary arteries to expand the lumen, thus increasing the blood flow o the heart in the case of coronary heart disease
What is Coronary Heart Disease?
- The lumen in the coronary arteries become narrow due to a build up of fatty material
- This reduces the amount of blood flow to the heart.
- Therefore, less glucose and oxygen reach the heart
- This means that there is less respiration
- Leading to less energy for the heart muscles to contract
So heart cells may die and a heart attack may happen
What are the implications of coronary heart disease
As less blood is flowing through the coronary arteries, less oxygen is being supplied to the heart muscle and so the heart cells cannot respire.
This can cause the cells in the heart to eventually die.
Name some benefits of using stents for coronary heart disease
Surgery is relatively quick and low risk
They last for a long time
Name some disadvantages of using stents for coronary heart disease
They require surgery which has risks, a heart attack during surgery or an infecction
They can potentailly lead to blood clots near the stent (thombrosis)
Fatty deposits can build up again
What do statins do?
Statins are drugs that reduce blood cholesterol levels.
This reduces the rate of fatty material deposit; this can help in the case of coronary heart disease
(but also strokes and heart attacks)
Name some disadvantages of statins
The drugs need to be taken regularly and some people may forget, this can increase the risk of them getting coronary heart disease
The drugs have side affects: head aches, kidney failure
What is the function of the heart valves
The valves open and close so that blood travels in one direction
Name ways in which heart valves can become faulty
The valves can become stiff and so they won’t open fully
or
The valve doesn’t close properly so blood can leak backwards
What are the consequences of a faulty valve?
less blood will reach the body
and
lungs can swell up with fluid
How are faulty valves fixed?
They are replaced with either a new biological or mechanical valve
What are biological valves?
Valves made of tissues or valves derived from human or animal donors such as pigs or cows