heart + blood vessels DEFINITELY IN EXAM Flashcards
what is the function of the arteries
to carry blood away from the heart at high pressures
Carry oxygenated blood, except for the pulmonary artery
what are some adaptations of arteries
- thick muscular elasticated walls to pump the blood and withstand it’s high pressure
- narrow lumen
what is the function of veins
to carry blood to the heart at low pressures
Always carry deoxygenated blood, except for the pulmonary vein
what are some adaptations of veins
- thin walls (carry blood at low pressures so don’t need thick walls)
- wide lumen
- contain valves (prevent blood from flowing backwards)
what do capillaries connect
arteries and veins
what is the function of capillaries
capillaries take waste products away by allowing the exchange of molecules between the blood and the body’s cells as molecules can diffuse across their walls
what are some adaptations of capillaries
- walls are 1 cell thick (minimises the diffusion pathway so substances can diffuse rapidly from the blood and the body cells)
what side of the heart is deoxygenated blood and where is it pumped to?
right side of the heart pumps deoxygenated blood to the lungs
what side of the heart is oxygenated blood and where is it pumped to?
left side of the heart pumps oxygenated blood to the body
where are the pacemaker cells
in the wall of the right atrium
what do pace maker cells do?
controls heart beat by electrical impulses
what is an artificial pacemaker
an electrical device that controls heart rate
define double circulatory system
the blood passes through the heart twice for every circuit of the body
(can pass blood through the body quicker meaning more oxygen to the working muscles)
what are the health issues caused by blocked coronary arteries
decreased blood flow so there is decreased oxygen to the heart muscle which causes strain on the heart and there is potential for a heart attack (where the heart is starved of oxygen)
what is a stent
an expandable tube in a coronary artery to keep them open
what are the advantages and disadvantages of a stent
advantages
- surgery is quick
- last a long time
- blood can flow normally through the artery
- don’t need to take a pill every day
disadvantages
- any surgery has risks (infection)
- blood clots near the stent (strokes)
- doesn’t prevent other regions of the coronary arteries from narrowing
- doesn’t treat the causes of the disease
what is a statin
a pill (that reduces blood cholesterol levels which slows down the rate of fatty material deposit in the arteries)
what are the advantages and disadvantages of a statin
advantages
- no surgery (no risk of infection)
- are an effective treatment
disadvantages
- have to take regularly
- side effects (headaches, kidney failure)
if valves get damaged what does that cause
valves don’t close properly so blood flows backwards
valves stay closed not enough blood passes through
what are the risks of biological and mechanical valves
biological valves
- risks with surgery
- need to take immunosuppressants
- abundance of cows (shorter waiting time)
cow new procedure so there are unknown risks
-possible objections on religious grounds
- human donors take a long time to find ( can only be used if the tissue is viable)
- valves may need to be replaced in the future
mechanical valves - risk of blood clots - risk of infections - need to take immunosuppressants \+ last a lifetime
name the sources of biological valves
human donors
cow/pig valves
what is heart failure
the heart can’t pump blood properly so the patient needs a new heart
what are the disadvantages associated with biological and artificial hearts
biological
- risk of rejection
- requires surgery (risk of infection)
- limited supply of donated hearts
- transplant list is long
- patient has to take immunosuppressants
artificial
- temporary solution
- requires surgery (risk of infection)
- need the surgery for a biological heart afterwards
- increase the risk of blood clots
explain why oxygen supply decreases as a result of CHD
fatty deposits in the coronary arteries
reduce blood flow
which decreases oxygen supply
what are the 4 chambers of the heart called
right ventricle
left ventricle
right atrium
left atrium
what are the 4 main blood vessels entering and leaving the heart
vena cava (deoxygenated blood from the body) pulmonary artery (carries deoxygenated blood from the heart to the lungs) pulmonary vein (carries oxygenated blood from the lungs to the heart) aorta (pumps oxygenated blood from the heart to the body)
the pattern of blood flow through the heart
blood enters the left and right atrium
the atria contract and blood is forced into the ventricles
the ventricles then contract and force blood out of the heart
the valves in the heart stop the blood from flowing backwards into the atria when the ventricles contract
why does the left side of the heart have a thicker muscular wall than the right
the left side of the heart has a thicker muscular wall because it pumps blood to the whole body so needs to provide a greater force
(whereas the right ventricle only pumps blood to the lungs)
what is the purpose of the coronary arteries?
to provide oxygen to the muscle cells of the heart
the oxygen is used in respiration to provide energy for contraction
what are cardiovascular diseases
cardiovascular diseases are diseases of the heart and blood vessels
