internal transport Flashcards
structure of heart
1.divided into 4 chambers
2.two upper chambers called atria, receive blood from lungs or body and transport it to the ventricles
3.two lower chambers called ventricles, pump blood out of the heart and all around the body
4.chambers on the left hand side and right hand side are completely separated by septum
systemic circulation
1.left atrium receives blood from the pulmonary vein, which carries blood from the lungs
2.blood flows to the left ventricle through the bicuspid valve
3.the blood in the left ventricle is pumped into the aorta, which takes the blood around the body
pulmonary circulation
1.the right atrium receives blood from the rest of the body, arriving through the vena cava
2.blood flows to the right ventricle through the tricuspid valve
3.the right ventricle pumps blood into the pulmonary artery which carries it to the lungs
effect of exercise on heart rate
1.heart rate increases so more blood reaches the muscles, more aerobic respiration and energy release, removal of excess co2 and lactic acid
2.during exercise muscles respire more releasing more carbon dioxide which dissolves in the plasma lowering the ph
3.chemoreceptors in cartoid artery and the aorta detect the acidic ph and send impulses to cardiovascular center in the brain medulla which sends impulse to pacemaker of the heart to increase the heart rat3
coronary heart disease
fats and glycerol build up in atheroma on walls of coronary artery blocking them, less blood reaches the heart muscle cells, so less o2, and glucose, less aerobic respiration resulting in cell death causing heart attack
causes of coronary heart disease
1.smoking
2.diet
3.stress
4.lack of exercise
treatment of coronary heart disease
1.stents
2.heart transplant
3.artificial heart
4.statins
5.plant stanol esters
6.beta blockers
stents
widen the narrowed or blocked coronary artery, allowing blood to flow through them
heart transplant
surgical transplant performed on patients with severe heart failure
advantages of heart transplant
lifesaving
disadvantages of heart transplant
1.few donors available
2.long recovery time
3.expensive
artificial heart
synthetic device made of plastic and some metal alloys, their purpose is to keep people alive while waiting for suitable donor
statins
chemicals that lower blood cholesterol, they inhibit an enzyme that is involved in the synthesis of cholesterol
plant stanol esters
lowers blood cholesterol levels
beta blockers
class of drugs, used to protect against second heart attack, they block receptors of adrenaline in various parts
causes of hypertension
genetic factors
high salt content
lack of exercise
obesity
smoking
kidney disease
features of arteries
1.very strong walls to withstand high pressure
2.have elastic tissue in their walls that can stretch and recoil
3.narrow lumen to maintain high pressure
4.walls of the arteries have muscles that control size of lumen
features of veins
1.lumen is wider in vein than in arteries to decreases resistance to blood flow
2.have valves in them to stop the blood flowing backwards
3.thin walls to be easily squeezed by skeletal muscles
adaption of capillary
thin walls for short diffusion distance
wall has pores for rapid exchange
function of capillary
1.allows transport of o2, glucose, amino acids, minerals, vitamins from blood to cells
2.allows co2 and urea out of cells to blood
plasma:
yellow part of the blood
function of plasma
transports water, dissolved nutrients, wastes, hormones, and co2
function of red blood cell
transports oxygen
adaption of red blood cell
biconcave to increase surface area to increase rate of diffusion
no nucleus to provide more space for haemoglobin
