Circulartory System- Blood

Question 1

what is the role of the red blood cells?

Answer 1

they carry oxygen from the lungs to all the cells in the body

Question 2

what are the features of red blood cells?

Answer 2

•their shape is a biconcave disc- this gives a large surface area for absorbing oxygen
•they don’t have a nucleus so there is more space to carry oxygen
•they contain a red pigment called haemoglobin

Question 3

what is the role of haemoglobin in the lungs?

Answer 3

it binds to oxygen to become oxyhaemoglobin

Question 4

what happens to haemoglobin in body tissue?

Answer 4

oxyhemoglobin splits up into haemoglobin and oxygen to release oxygen into cells

Question 5

what is the role of the white blood cells?

Answer 5

•some can change shape to engulf pathogens in a process called phagocytosis
•others produce antibodies to fight pathogens as well as antitoxins to neutralise any toxins produced by microorganisms

Question 6

do white blood cells have a nucleus?

Answer 6

yes

Question 7

what are platelets?

Answer 7

a small fragment of cells with no nucleus

Question 8

what is the role of platelets?

Answer 8

they help blood to clot at a wound to stop blood pouring out and to stop microorganisms getting in

Question 9

what do plasma carry?

Answer 9

•red blood cells, white blood cells and platelets
•glucose and amino acids
•carbon dioxide
•urea
•hormones
•proteins
•antibodies and antitoxins

Question 10

What can a lack of platelets cause?

Answer 10

can cause excessive bleeding and bruising