Circulatory System

Transports; oxygen & nutrients to the cells, CO2 and wastes away from cells Regulation; PH, body temp Projection; clotting and disease fighting

Protect body from infection Remove dead/injured cells Lifespan few minutes-years

3% in blood plasma 97% in oxyhaemoglobin

Contains haemoglobin No nucleus= more room for haemoglobin Biconcave = increased surface area for oxygen exchange

O2 + haemoglobin = oxyhaemoglobin when O2 concentration in the lungs is high Oxyhaemoglobin = haemoglobin + O2 when O2 is low in the tissues

CO2 diffuses into plasma due to concentration differences 7-8% dissolved in plasma 22% combines with haemoglobin to form carbaminohaemoglobin 70% carried in plasma as bicarbonate ions (HCo3-)

Vasoconstriction: muscle contracts to reduce blood flow to an organ Vasodilation: substances are sent to the arterioles to relax them, increasing blood flow

• Platelets release substances that vasoconstrict • Mesh forms that traps platelets, blood cells and plasma • Mesh forms scab • Clot reaction occurs • Serum squeezed out pulling edges together • Clot dries to form a scab

Ensures blood only flows in one direction

Pumps deoxygenated blood from right ventricle to the lungs, returns oxygenated blood to the left atrium

Pumps oxygenated blood from the left ventricle to the tissues, returns deoxygenated blood to the right atrium

Systole: pumping/contraction phase Diastole: filling/relaxing phase