Human transport Flashcards
(20 cards)
why is the circulatory system essential for survival
- the circulatory system delivers oxygen around the body
- this oxygen is required by cells to carry out aerobic respiration in all of our cells to release energy
what is a double circulatory system
- means the blood passes through the heart twice in one complete cycle
- travels from the heart to the lungs (picks up oxygen that will diffuse into the blood from the alveoli lungs) to the heart, to the rest of the body before returning to the heart
pulmonary circuit
- right side of heart pumps blood to lungs where it is oxygenated and taken back to left side of heart
- carbon dioxide diffuses from the blood into the air in the alveoli
- oxygen diffuses from the air in the alveoli into the blood and its absorbed by haemoglobin in the red blood cells
- the pulmonary artery carries deoxygenated blood and the pulmonary vein carries oxygenated blood
systematic circuit
- left side of heart pumps blood around the body where oxygen is unloaded
- it transports blood around the body. it transports oxygen to the body tissues and carries away deoxygenated blood containing carbon dioxide and other waster materials
vessels - aorta
major artery that takes oxygenated blood from the heart to the rest of the body
vessels - hepatic artery
supplies the liver with oxygenated blood
vessels - pulmonary vein
carries oxygenated blood from the lungs back to the heart
vessels - renal artery
supplies the kidneys with oxygenated blood
vessels - pulmonary artery
carries deoxygenated blood from the heart to the lungs to pick up oxygen
vessels - hepatic portal vein
carries deoxygenated blood from the digestive system to the liver
vessels - renal vein
takes deoxygenated blood away from the kidneys
vessels - superior vena cava
takes deoxygenated blood from the head to the arms to the heart
vessels - inferior vena cava
takes deoxygenated blood from the organs in the lower body back to the heart
artery
- carries blood away from the heart to the organs. carries deoxygenated blood
- narrow lumen to maintain pressure
- thick muscle to aid elasticity and maintain pressure. contains elastic fibres for stretch and recoil
- no valves
- thick outer walls to maintain pressure
vein
- lower pressure - carry deoxygenated blood from the body to the heart
- wider to assist in flow
- thinner with less elastic muscle
- valves prevent backflow (through gravity)
- thinner outer walls (doesn’t need to maintain pressure)
capillary
- carries nutrients/gases to tissues, removes waste products
- has lumen
- no smooth muscle
- no valves
- single cell thick walls to allow nutrients and gases to diffuse through
the cardiac cycle
STAGE 1
- blood enters atria
- it cannot pass into the ventricles because the tricuspid and bicuspid valves are shut
STAGE 2
- walls of atria contract (systole)
- high blood pressure in atria forces open tricuspid and bicuspid valves
- blood forced into the ventricles
STAGE 3
- the ventricles contract (systole)
- - forces the bicuspid and tricuspid valves to close
STAGE 4
- ventricles continue to contract and this forces open the semi-lunar valves
- blood is forced into the aorta and the pulmonary artery
STAGE 5
- as the ventricles relax (diastole) the semi-lunar valves close
- the cycle starts again as the atria fills with blood
coronary circulation
- this is the hearts own blood supply
- it gets this from the coronary arteries
- oxygen is needed by muscle cells because contraction needs energy
- the coronary arteries are among the narrowest in the body
- they are easily blocked by a build up of fatty substances (including cholesterol) in their walls
- this can cut off blood supply to an area of cardiac muscle
- the affected muscle can no longer receive oxygen and glucose, so it cannot respire and release energy
- this means it is unable to contract, resulting in heart attack
risk factors of coronary heart disease
HEREDITY
- some people inherit a tendency to develop coronary heart disease
HIGH BLOOD PRESSURE
- puts more strain on the heart
DIET
- eating large amount of saturated fat is likely to raise cholesterol levels
SMOKING
- raises blood pressure and makes blood clots more likely to form
STRESS
- raises blood pressure
LACK OF EXERCISE
- regular exercise helps to reduce blood pressure and strengthens the heart
composition of blood
red blood cells
- the red blood cells are highly specialised cells that have one function - to transport oxygen. Red bloodcells contain
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