Biology unit 3 topic 2

Created by: Rachel12341
Created on: 11-05-14 16:17

Circulatory system

Consists of blood vessels, the heart and blood. The right pump forces deoxygenated blood to lungs where it picks up oxygen and loses CO2. It reruns to heart in left side and pumps to whole body. This is a double circulation

1 of 10

Heart

consists of 4 chambers – upper ones – atria receive blood from vena cava on right and pulmonary vein on left. Ventricles contract, pump blood to pulmonary artery from right and into aorta on left. Valves in heart prevent backflow

2 of 10

Keeping blood flowing

Arteries – carry blood away from heart, have thick walls containing muscle and elastic tissue. Veins – thinner walls, often have valves. Capillaries – narrow, thin wlled, carry blood through organs + allow exchange of substances with all cells inbody

3 of 10

Stents

If vessels too blocked or narrow blood wont flow efficiently, organics ca be deprived of oxygen + nutrients. Stents inserted to keep vessels open.

4 of 10

Transport in the blood

Blood is a tissue. Fluid plasma contains red blood cells, white blood cells & platelets. The plasma carries CO2, soluble products of digestion, urea.

5 of 10

Red blood cells

Biconcave discs which have no nucleus, they contain the red pigment haemoglobin which combines with oxygen to form oxyhaemoglobin in the lungs. They carry oxygen to all the organs where they break off from the oxygen

6 of 10

White blood cells + platelets

WBC have a nucleus and form part of the body’s defences. Platelets are small fragments of cells that have no nucleus and help blood to clot at the site of a wound.

7 of 10

Artificial + real blood

Donated blood is separated into cells & plasma + must be refrigerated. The plasma can be given to patients in a transfusion to increase blood volume. Artificial doesn’t need refrigerating or to match but doesn’t carry as much oxygen + expensive.

8 of 10

Artificial hearts

they do not need to match the person’s tissue and no need for immunosuppressant drugs. However there are problems with blood clotting, long stays in hospital and expense.

9 of 10

Xylem + phloem

Xylem tissue transports water + mineral ions from roots to stems, leaves etc. Phloem tissue carries dissolved sugars from the leaves to the rest of the plant.

10 of 10

Other cards in this set