Functions of the Blood

Question 1

What are the 4 main Main Components of blood

Answer 1

Plasma, Platelets, Red Blood Cells, and White Blood Cells

Question 2

What is Plasma?

Answer 2

Plasma is the pale yellow liquid that carries just about everything in the blood.

Question 3

What does Plasma carry?

Answer 3

• RED and WHITE blood cells and Platelets.
• Digested food like GLUCOSE and AMINO ACIDS from the gut to the body cells
• CARBON DIOXIDE from the body cells to the lungs
• UREA from the liver to the kidneys
• HORMONES which act as chemical messengers
• HEAT ENERGY

Question 4

What are Platelets?

Answer 4

Platelets are small fragments of cells that help the blood Clot.

Question 5

When you damage a blood vessel, what happens?

Answer 5

The Platelets clump together to “plug” the damaged area.

Question 6

What is blood clotting and give 2 reasons it happens?

Answer 6

Blood clotting is when platelets clump together and plug the damaged bit is a blood vessel.
It stops you loosing too much blood and it prevents microorganisms from entering the wound.

Question 7

What holds the platelets together in a clot

Answer 7

A protein FIBRIN. Also other CLOTTING FACTORS are needed too.

Question 8

What do RED BLOOD CELLS do?

Answer 8

They carry OXYGEN from the LUNGS to all the cells in the body.

Question 9

How are the red blood cells adapted to their job? 6 marks

Answer 9

They are SMALL and have a BICONCAVE SHAPE to give a LARGE SURFACE AREA for ABSORBING and RELEASING OXYGEN.
They contain HAEMOGLOBIN which gives blood its colour and contains IRON. In the lungs HAEMOGLOBIN REACTS with OXYGEN to become OXIHAEMOGLOBIN. In the body tissues the reverse happens to RLEASE OXYGEN to the cells.
Rd bloods cells don’t have a NUCLEUS as this frees up SPACE for more HAEMOBLOBIN, so they can carry more oxygen.

Question 10

What are pathogens?

Answer 10

They are microorganisms that cause disease eg bacteria or viruses.

Question 11

What fights these pathogens?

Answer 11

The immune system and white blood cells.

Question 12

Name the two different types of white blood cells.

Answer 12

Phagocytes and lymphocytes.

Question 13

How do PHAGOCYTES work?

Answer 13

They detect things that are foreign to the body, ENGULF them and then DIGEST them.
Phagocytes are non specific - they attack anything that’s not meant to be there.

Question 14

What do LYMPHOCYTES produce?

Answer 14

ANTIBODIES.

Question 15

What unique molecule does a pathogen have?

Answer 15

ANTIGENS

Question 16

How do LYMPHOCYTES work?

Answer 16

When a lymphocyte comes across a foreign antigen they start to produce antibodies - these lock onto the invading pathogen and mark them out for destruction by other white blood cells.
The antibodies produced are specific to that type of antigen. They are produced rapidly.

Question 17

What are MEMORY CELLS?

Answer 17

They are produced in response to a foreign antigen. These remain in the body and remember a specific antigen. They operate very fast if the same antigen enters the body again.

Question 18

How does a vaccination work?

Answer 18

Vaccination involves injecting dead or inactive pathogens into the body.
These carry antigens so even though they’re harmless they still trigger an immune system response - your lymphocytes produce antibodies to attack them.
Memory cells will also be produced and will remain in the blood, so if a live pathogen of the SAME TYPE ever appear, the ANTOBODIES to kill them will be produced much faster and in greater numbers.