The Blood And Blood Vessels - Part 1 (T2)

Question 0

Around how much blood is in the human body?

Answer 0

Around 5 litres.

Question 1

What is human blood made of?

Answer 1

Plasma, blood cells and platelets.

Question 2

Where are blood cells produced?

Answer 2

In the bone marrow.

Question 3

Describe plasma and what it is made of…

Answer 3

• it has a yellowish appearance.
• contains dissolved carbon dioxide, a waste gas of respiration.
• contains dissolved glucose, amino acids, fatty acids and glycerol; molecules used to feed the cells to create respiration and to help them build and repair.
• contains urea, a waste product of digestion, lost from the kidneys.
• contains antibodies and antitoxins to protect the body from disease and poisons.
• contains hormones, controlled chemicals for many of our body functions.
• contains mineral salts, used to keep the body healthy and well functioning.

Question 4

What is the function of the red blood cells?

Answer 4

To transport oxygen around the body.

Question 5

What is the scientific name for red blood cells?

Answer 5

Erythrocytes

Question 6

How are red blood cells different from normal cells, and how does this benefit their function?

Answer 6

Red blood cells do not contain a nucleus or any other organelles, so they can carry as much oxygen as possible.

Question 7

What shape are red blood cells and how does this benefit their function?

Answer 7

Red blood cells are a doughnut shape with a lowered, flattened centre instead of a hole. This shape increases their surface area so they can absorb a lot of oxygen.

Question 8

What important molecule do red blood cells contain, and what does it do?

Answer 8

Red blood cells contain haemoglobin. This is a pigment which gives blood its colour and a molecule that transports oxygen.

Question 9

How does haemoglobin transport oxygen?

Answer 9

When blood takes oxygen from the lungs, haemoglobin forms weak bonds with oxygen to produce a new molecule; oxyhemoglobin. As oxyhemoglobin passes cells it releases the oxygen, leaving the haemoglobin able to move on and pick up more oxygen.

Question 10

What element is needed to produce haemoglobin and if you are deficient in it in it what illness can you develop?

Answer 10

Iron is needed to produce haemoglobin and if you do not get enough you can develop anaemia

Question 11

How do red blood cells get through the narrowest of capillaries and why is it important that they do?

Answer 11

Red blood cells have a flexible outer membrane. This means they can fit through the narrowest of capillaries and get oxygen to all body cells and tissues.

Question 12

What is the scientific name for white blood cells?

Answer 12

Leucocytes.

Question 13

What is the man in function of white blood cells?

Answer 13

They form part of the body’s immune system.

Question 14

Explain how white blood cells operate within the immune system…

Answer 14

When disease is detected, the corresponding white blood cell is copied until many are produced to attack the invading foreign cell.

Question 15

What is a phagocyte?

Answer 15

A type of white blood cell that eats invading cells.

Question 16

What is a lymphocyte?

Answer 16

A type of white blood cell that produces antibodies to attack invading cells.

Question 17

How do lymphocytes protect the human body?

Answer 17

• a type of lymphocyte called a plasma produces specific protein chemicals called antibodies to destroy specific pathogens.
• they recognise pathogens by proteins on their surface called antigens.
• lymphocytes also produce memory cells which remain in the body for a long time in case reinfection occurs.
• if it does, the antibodies can be produced faster with the help of the memory cells.

Question 18

What are platelets and why are they so important?

Answer 18

Platelets are fragments of larger cells and their function is to form part of a clot. They plug a wound, stopping blood from being lost as well as any micro-organisms entering the body. Without them, we would bleed to death from a small cut.