The Heart Flashcards
What type of circulatory system do humans have?
Double circulatory system
How does the circulatory system work?
- Oxygenated blood flows from the lungs through the pulmonary vein into the left atrium
- The atrium contracts pushing blood into the left ventricle
- The ventricle contracts forcing blood into the aorta
- The blood flows around the body to organs through arteries
- It returns deoxygenated through the vena cava
- The right atrium contracts and then the right ventricle contracts, pushing it out of the pulmonary artery and into the lungs
What do valves do?
Prevent backflow
What is the pacemaker?
A group of cells in the right atrium that produces an electric impulse that causes the heart muscle to contract
What type of arteries branch off the aorta to bring in oxygenated blood?
Coronary arteries
What is coronary heart disease?
When the coronary arteries supplying blood to the heart get blocked by layers of fatty material building up, causing a lack of oxygen to the heart (and potentially heart attacks)
What is a disadvantage of stents?
There is a risk of complications during the operation and facing an infection from the surgery
What are stents?
Tubes inserted inside arteries, keeping them open to reduce risk of heart attack
What is cholesterol?
An essential lipid, but too much of a certain type of it (LDL) can cause fatty deposits in arteries
What are statins?
Drugs that an reduce the amount of bad cholesterol in the bloodstream
What are some advantages of statins?
- Reduce the risk of heart attack, stroke and CHD
- Increase HDL (good cholesterol)
What are some disadvantages of statins?
- Long term drug that must be takes regularly
- Can have negative side effects
- Takes time for effect to kick in
Why might an artificial heart be used instead of a heart transplant?
- Donors may not be available
- Bad fit for the patient
What is an artificial heart?
A mechanical device that pumps blood for a person whose heart has failed
What is the advantage of an artificial heart?
Less likely to be rejected by the immune system
What are some disadvantages of artificial hearts?
Surgery can lead to bleeding and infection
Don’t work as well as natural ones - could wear away or have mechanical failures
Blood doesn’t flow as smoothly - blood clots and strokes
Have to take drugs to thin blood, causes problems with bleeding if hurt
How can valves be damaged?
Heart attack, infection or old age, causing it to become stiffer so it won’t open properly or become leaky, allowing backflow
Where do replacement valves come from?
Other humans, mammals (cows, pigs) or mechanical
