Circulatory system - blood

Question 1

What is the job of the RBC ?

Answer 1

carry oxygen from lungs to all cells in the body

Question 2

function of RBC

Answer 2

Their shape is a biconcave disc, this gives a large SA for absorbing oxygen .

They don’t have a nucleus - this allows more room to carry oxygen

They contain a red pigment called haemoglobin

Question 3

Job of Haemoglobin

Answer 3

in the lungs, haemoglobin binds to oxygen to become oxyhaemoglobin . In body tissues, the reverse happens - oxyhaemoglobin splits up into haemoglobin and oxygen, to release oxygen to the cells

Question 4

WBC
defend against infection

Answer 4

some can change shape to engulf microorganisms = phagocytosis

Others produce antibodies to fight micro organisms as well as antitoxins to neutralise any toxins produced by the micro organisms

Unlike RBC, they do have a nucleus

Question 5

what are Platelets and how do they help the blood ?

Answer 5

These are small fragments of cells. They have no nucleus.

They help the blood to clot at a wound - to stop all your blood pouring out and to stop microorganisms getting in.

Lack of platelets can cause excessive bleeding and bruising

Question 6

What is Plasma and what does it carry ??

Answer 6

pale straw coloured liquid which carries just about everything
- red and WBC and platelets
- nutrients like glucose and amino acids, These are the soluble products of digestion which are absorbed from the gut and taken to the cells of the body
- co2 from organs to lungs
- Urea from liver to kidneys
- hormones
- proteins
- antibodies and antitoxins produced by the WBC