1.2 Functions of Blood

Question 1

What are the 5 functions of blood?

Answer 1

• Transport
• Temperature regulation
• Exchange of materials in body tissues
• Preventing infection
• Blood clotting

Question 2

What are the 3 things transport does?

Answer 2

• Transports elements required for life around the body.
• Transports gases such as oxygen and carbon dioxide.
• Transports hormones.

Question 3

Give an example of transportation of elements required for life around the body.

Answer 3

Many elements are transported from the digestive system to the tissues or storage areas such as the liver.

Question 4

What are lipoproteins?

Answer 4

These are proteins that carry elements that cannot be dissolved in water, for example fats.

Question 5

What are the two main forms of lipoproteins?

Answer 5

• High density lipoprotein (HDL)

- Low density lipoprotein (LDL)

Question 6

What does HDL do?

Answer 6

HDL is known as ‘good cholesterol’. It prevents and even reverses the harmful deposits from LDL.

Question 7

What does LDL do?

Answer 7

LDL is known as ‘bad cholesterol’. It deposits fat and cholesterol in the walls of the arteries.

Question 8

Give an example of transportation of gases.

Answer 8

Blood transports gases such as oxygen and carbon dioxide between the tissues and the lungs.

Question 9

What is haemoglobin?

Answer 9

An iron-containing protein in red blood cells.

Question 10

What is oxyhaemoglobin?

Answer 10

A bright red substance created as a result of the combination of oxygen and haemoglobin. In the tissues, oxygen is released and the darker haemoglobin is reformed.

Question 11

List 3 adaptions of erythrocytes.

Answer 11

1. To increase the space for carrying the maximum amount of haemoglobin, erythrocytes have no cell nucleus.
2. They also have a special disk shape to help the exchange of oxygen.
3. The haemoglobin on the return trip to the lungs will also carry a small amount of carbon dioxide.

Question 12

Give an example of the transportation of hormones.

Answer 12

Blood transports hormones such as insulin and adrenalin which are chemicals produced in glands.

Question 13

How are hormones transported by the blood?

Answer 13

Hormones travel in the blood to target organs where they trigger a response or initiate a process for example:

• Growth
• Fertility
• Fight or flight

Question 14

What is our optimal temperature?

Answer 14

37 degrees centigrade.

Question 15

Why does our internal temperature need to be regulated?

Answer 15

Because life is maintained by millions of chemical reactions that are all affected by heat.

Question 16

What regulates our temperature?

Answer 16

Proteins called enzymes.

Question 17

What happens to enzymes when our temperature is too high or too low?

Answer 17

Like all proteins, enzymes become unusable or denatured at high temperatures and chemical reactions slow down at low temperatures. This is why our optimal temperature must be maintained for good health.

Question 18

Where is heat generated and what does blood do with this heat?

Answer 18

Heat is generated in all our cells but especially in tissues such as the muscles. Blood removes this heat and circulates it around the body.

Question 19

How is blood involved in the immune response when combating infection?

Answer 19

Through leucocytes (white blood cells).

Question 20

What do the neutrophils, lymphocytes and monocytes do?

Answer 20

These cells recognise the pathogens as threats. The neutrophils act as antigens as they produce special proteins called antibodies which lock onto pathogen walls, immobilising them and making them targets for the monocytes. The monocytes then kill the pathogens and break them down. The lymphocytes will now remember these particular pathogens and can therefore respond quickly if this infection enters the body again.

Question 21

How do lymphocytes help destroy viruses?

Answer 21

Viruses cannot live independently and therefore need to hijack cells to survive and reproduce. They change the outside of the injected cell but the lymphocytes recognise this and latch onto the cell and destroy it along with the virus. This process is what causes symptoms of viral infections.

Question 22

What are the 2 risks of a break in the skin?

Answer 22

• Losing 2 or more litres of blood can lead to serious issues or death.
• Pathogens can enter the blood, causing issues such as blood poisoning or sepsis which can cause organ damage.

Question 23

What do platelets do?

Answer 23

Trigger blood clotting and also help activate the immune response which minimises the threat of a pathogenic invasion.

Question 24

How does blood clotting occur?

Answer 24

When exposed to air or foreign material such as glass or plastic, platelets activate a chain reaction known as coagulation.

Question 25

What is coagulation?

Answer 25

This chain reaction coverts fibrinogen (soluble blood protein) into fibrin (an insoluble form) that forms a net-like structure. This traps both platelets and erythrocytes to form a clot.

Question 26

What fibrinogen?

Answer 26

The soluble blood protein.

Question 27

What is fibrin?

Answer 27

The insoluble blood protein.

Question 28

What is haemophilia?

Answer 28

A condition where an individual lacks one or more of these blood clotting factors and so have longer clotting times which can lead to chronic blood loss.