Blood

Question 1

What is the function of the cardiovascular system

Answer 1

It delivers materials needed by the cells of the body and carries away the waste products of their metabolism. It also carries out other functions such as carrying hormones from one part of the body to another, forming part of the defence system of the body and distributing heat

Question 2

What are the 3 main things the blood does

Answer 2

Transport, defence and the formation of tissue fluid and lymph

Question 3

What is the role of plasma

Answer 3

It transports digested food products (e.g glucose) from the small intestine to all other parts of the body where they are needed, it transports nutrient molecules from storage areas to the cells that need them, it transports excretory products (e.g urea ) from cells to the organs such as the lungs or kidneys that excrete them from the body and it transports hormones from where they are made to where they cause changes in the body

Question 4

What are erythrocytes

Answer 4

They contain haemoglobin and are formed in the bone marrow and mature erythrocytes do not contain a nucleus and have a limited life of about 120 days. They transport oxygen from the lungs to all cells and they have a biconcave disc shape that means they have a large surface area to volume ratio so oxygen can diffuse into and out of them rapidly. Haemoglobin carries some of the co2 produced in respiration back to the lungs

Question 5

What are leucocytes

Answer 5

Leucocytes are much larger than erythrocytes but can also squeeze through tiny blood vessels as they can change their shape. They are formed in the bone marrow although some mature in thymus gland. Their main function is to defend the body against infection. They all contain a nucleus and have colourless cytoplasm. There are different types of leucocytes.

Question 6

What are the different types of leucocytes

Answer 6

Granulocytes which include neutrophils, eosinophils, basophils, agranulocytes which include monocytes and lymphocytes

Question 7

What are granulocytes

Answer 7

These are leucocytes that have granules in the cytoplasm of the cells that take up stain and are obvious under the microscope. They have lobed nuclei and granulocytes include: neutrophils, eosinophils and basophils.

Question 8

What are neutrophils

Answer 8

Part of the non specific immune system they engulf and digest pathogens by phagocytosis. They have multi lobed nuclei. Up to 70% of all leucocytes are neutrophils.

Question 9

What are eosinophils

Answer 9

Part of the non specific immune system. They are stained red by eosin stain. They are important in the non specific immune response of the body against parasites in allergic reactions and inflammation and in developing immunity to disease

Question 10

What are basophils

Answer 10

Part of the non specific immune system. They have a two lobed nucleus. They produce histamines involved in inflammation and allergic reactions

Question 11

What are agranulocytes

Answer 11

These leucocytes do not have granules to take up stain in their cytoplasm. They have unlobed nuclei. Agranulocytes include: monocytes and lymphocytes

Question 12

What are monocytes

Answer 12

Part of the specific immune system. They are largest of the leucocytes. They can move out of the blood into the tissues to form macrophages which also play an important part in the specific immune system. They engulf pathogens by phagocytosis

Question 13

What are lymphocytes

Answer 13

Small leucocytes with very large nuclei that are vitally important in the specific immune response of the body

Question 14

What are platelets

Answer 14

Platelets are tiny fragments of large cells called megakaryocytes which are found in the bone marrow. They are involved in the clotting of the blood.