2B Flashcards
(17 cards)
where does deoxygenated blood flow?
into the right atrium, then the right ventricle
where does oxygenated blood flow?
into the left atrium and then into the left ventricle
what does the right ventricle do?
pumps deoxygenated blood to the lungs to undergo gaseous exchange
what does the left ventricle do?
pumps oxygenated blood around the body
describe the muscular wall of the heart
they provide a strong heartbeat and the muscular wall of the left ventricle is thicker, so blood can be pumped around the whole body
what do the four chambers of the heart do?
they separate oxygenated blood from the deoxygenated blood
what do the heart valves do?
they make sure that blood does not flow backwards
what do the coronary arteries do?
they cover the heart to provide its own oxygenated blood supply
what is the 1st step of blood flow? (vena cava)
blood flows into the right atrium through the vena cava, and the left atrium through the pulmonary vein
what is the 2nd step of blood flow? (atria)
the atria contracts forcing the blood into the ventricles
what is the 3rd step of blood flow? (artery)
the ventricles contract, pushing the blood in the right ventricle into the pulmonary artery to be taken to the lungs, and blood in the left ventricle to the aorta to be taken around the body
what happens during blood flow? (valves)
the valves close, to prevent the backflow of blood
how is a heartbeat controlled?
it is controlled by a group of cells found in the right atrium that act as a pacemaker
how does a pacemaker work?
they provide electrical impulses which pass across the heart muscle, causing it to contract
what would happen without a pacemaker?
the heart would not pump fast enough to deliver the required amount of oxygen to the whole body
describe the role of arteries
- they carry blood away from the heart.
- they have layers of muscle in the walls to make them strong
- they have elastic fibres to allow them to stretch
- this allows them to withstand high pressure
describe the role of veins
- they carry blood towards the heart.
- their lumen is wide to allow low pressure blood to flow through.
- they have valves to prevent the backflow of blood
