THE BLOOD

Question 1

What are erythrocytes? (1)

Answer 1

Red blood cells

Question 2

What are leucocytes? (1)

Answer 2

White blood cells

Question 3

What does plasma carry? (6)

Answer 3

Plasma carries; -nutrients from gut to liver to all cells
-excretory products
-hormones from the endocrine gland to all tissues and organs
-dissolved proteins that have a role in regulating the osmotic concentration of the blood
-dissolved proteins that are antibodies
-heat to all tissues.

Question 4

What are the functions of plasma? (4)

Answer 4

-carry water-soluble materials around the body
-help maintain body temperature
-acts as a buffer to pH changes
-contains platelets

Question 5

What does the blood carry? (3)

Answer 5

-erythrocytes
-leucocytes
-plasma

Question 6

What are the several types of white blood cells? (4)

Answer 6

-neutrophils
-monocytes
-eosinophils
-lymphocytes

Question 7

What is the function of neutrophils and monocytes? (1)

Answer 7

They engulf and digest pathogens by phagocytosis

Question 8

What is the function of eosinophils? (2)

Answer 8

Involved in allergic responses and protection against viruses and parasitic worms.

Question 9

What is the function of lymphocytes, type B? (1)

Answer 9

To make antibodies.

Question 10

What is the function of lymphocytes, type T? (1)

Answer 10

Help kill tumour cells and help control immune responses.

Question 11

What is the function of platelets? (1)

Answer 11

They are involved in blood clotting.

Question 12

What is the function of red blood cells? (2)

Answer 12

-oxygen from the lungs to respiring tissues
-carbon dioxide from respiring tissues to the lungs

Question 13

What is the main need for high blood pressure? (1)

Answer 13

To drive the blood around the body to the tissues and organs.

Question 14

What happens during systole (heart contraction)? (1)

Answer 14

Blood is pumped through the aorta and other arteries at high pressure. The elastic fibres of the arteries enable them to expland and allow blood through.

Question 15

What happens during diastole (heart relaxation)? (1)

Answer 15

The blood pressure in the arteries drops, the elastic recoil of the artery walls help forced the blood on.

Question 16

What are varicose veins? (2)

Answer 16

When a vein wall becomes weakened, valves may no longer close properly which allows back flow of blood causing the vein to become enlarged and bumpy (varicose).

Question 17

Where do varicose veins usually occur? (1)

Answer 17

In superficial veins near the skin surface in lower legs.

Question 18

How are varicose veins usually treated? (1)

Answer 18

They can be surgically removed without affecting blood flow as most blood is returned to the heart by deep veins.

Question 19

What are the functions of the blood? (4)

Answer 19

-transport
-defence
-thermoregulation
-maintaining pH of body fluids

Question 20

How are red blood cells specialised? (4)

Answer 20

-have a flattened bioconcave shape
-large amount of haemoglobin
-no nucleus or organelles
-diameter of 6-8 micrometers larger than a capillary diameter

Question 21

Why does a red blood cell having a flattened bioconcave shape help it to perform its function? (1)

Answer 21

Ensures a large surface area to volume ratio for efficient gas exchange.

Question 22

Why does a red blood cell having a large amount of haemoglobin help it to perform its function? (1)

Answer 22

For transporting oxygen, it binds to it.

Question 23

Why does a red blood cell having no nucleus or organelles help it to perform its function? (1)

Answer 23

Maximises space for haemoglobin so more oxygen can be transported.

Question 24

Why does a red blood cell having a -diameter of 6-8 micrometers larger than a capillary diameter help it to perform its function? (1)

Answer 24

Slows blood flow to allow diffusion of oxygen.

Question 25

which out of the three blood vessels have an outer layer (tonica externa)? (3)

Answer 25

Artery- present
Capillary- absent
Veins- present

Question 26

which out of the three blood vessels have an middle layer (tunica media)? (3)

Answer 26

Artery- thick layer
Capillary- absent
Veins- thin layer

Question 27

which out of the three blood vessels have an endothelium (tunica intima)? (3)

Answer 27

Artery- absent
Capillary- absent
Veins- present

Question 28

What is a tunica intima? (1)

Answer 28

‘Pavement epithelium’ or valves.

Question 29

What is a tunica media? (1)

Answer 29

Smooth involuntary muscle.

Question 30

What is pulmonary circulation? (1)

Answer 30

The pathway of arteries, veins and capillaries carrying blood from the heart to the lungs and back to the heart.

Question 31

What is systemic circulation? (1)

Answer 31

The pathway of arteries, veins and capillaries carrying blood from the heart to all the bodies tissues and back to the heart.

Question 32

What route does pulmonary circulation take? (6)

Answer 32

Pulmonary artery - artériole - capillary - venule - vein - pulmonary vein

Question 33

What route does systematic circulation take? (6)

Answer 33

Aorta - artériole - capillary - venule - vein - vena cava

Question 34

What is meant by elastic arteries? (2)

Answer 34

Elastic fibres and smooth muscle in the walls of arteries are stretched when the blood is at high pressure, some of the energy in the blood is stored at potential energy in the elastic walls, when the pressure of the blood falls this energy is used to maintain the flow until the ventricles contract.