Circulatory System Flashcards
Functions of the blood
Transports; oxygen & nutrients to the cells, CO2 and wastes away from cells
Regulation; PH, body temp
Projection; clotting and disease fighting
White blood cells (leucocytes) functions
Protect body from infection
Remove dead/injured cells
Lifespan few minutes-years
Transport of oxygen
3% in blood plasma
97% in oxyhaemoglobin
Red blood cells (erythrocyte) characteristics
Contains haemoglobin
No nucleus= more room for haemoglobin
Biconcave = increased surface area for oxygen exchange
Oxyhaemoglobin build up and break down
O2 + haemoglobin = oxyhaemoglobin when O2 concentration in the lungs is high
Oxyhaemoglobin = haemoglobin + O2 when O2 is low in the tissues
CO2 transport
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-)
Blood flow in arteries
Vasoconstriction: muscle contracts to reduce blood flow to an organ
Vasodilation: substances are sent to the arterioles to relax them, increasing blood flow
Process of blood clotting
- 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
Function of valves
Ensures blood only flows in one direction
What is pulmonary circulation
Pumps deoxygenated blood from right ventricle to the lungs, returns oxygenated blood to the left atrium
What is systemic circulation
Pumps oxygenated blood from the left ventricle to the tissues, returns deoxygenated blood to the right atrium
Define systole and diastole
Systole: pumping/contraction phase
Diastole: filling/relaxing phase
