transport in humans Flashcards
function of arteries
carry oxygenated blood and have thick walls to withstand high blood pressure
function of capillaries
exchange substances to and from tissues ,they branch repeatedly to increase satvr for more efficient exchange of substances
function of veins
carry blood towards heart and have thinner muscular walls and semi lunar valves to prevent backflow of blood
what are red blood cells
no nucleus they contain haemoglobin that combine reversibly with oxygen and binds to form oxyhaemoglobin
what are white blood cells
phagocytosis process which a white blood cells engulf and destroy foreign particles
flow of right atrium in heart
receives deoxygenated blood from body
flow of right ventricle in heart
pumps deoxygenated blood into lungs
flow of left atrium
receives oxygenated blood from lungs
flow of left ventricle
pumps oxygenated blood to the body
flow of vessels in heart
vena cava transports deoxygenated blood to right atrium
aorta transports oxygenated blood from left ventricle to body
pulmonary artery transports deoxygenated blood to lungs
pulmonary vein transports oxygenated blood to left atrium
cardiac cycle
1) oxygenated blood from lungs enter left atrium via pulmonary vein.
2) left ventricle muscle contracts
3) deoxygenated blood from various parts of body return to right atrium via vena cava.
4) right ventricle muscle contracts and blood is pumped into the lungs
disease that can occur
coronary heart disease where it is the blockage of coronary arteries that lead to reduced blood flow to the heart muscleswhich reduces supply of oxygen and nutrients to heart muscles
ways to prevent disease and factors that increase risk
regular exercise nosmoking proper diet,sedentary lifestyle smoking
