Unit 5: Blood and Organs

Question 1

What are the four main components of blood

Answer 1

• Plasma
• Platlets
• Red blood cells
• White blood cells

Question 2

What is the function of plasma

Answer 2

Plasma is a pale yellow liquid that transports things around the body such as:
* Red blood cells, white blood cells and platlets
* Glucose
* Amino acids
* Carbon dioxide
* Urea
* Hormones
* Heat energy

Question 3

What is the function of platlets

Answer 3

• Platlets form clots around a damaged area
• These clots stop a person from losing too much blood

Question 4

What is the function + properties of red blood cells

Answer 4

• They are small and have a biconcave shape which allows them to have a larger surface area to transfer more oxygen around the body
• They contain haemoglobin which reacts with oxygen to form oxyhaemoglobin to release to the cells
• Red blood cells don’t have a nucleus, this frees up space for more haemoglobin

Question 5

What are the two types of white blood cells in the body

Answer 5

• Phagocytes
• Lymphocytes

Question 6

How do phagocytes take care of pathogens

Answer 6

• Phagocytes detect things that are foreign to the body
• Once they see something foreign they engulf it and digest it using digestive enzymes
• They are non specific

Question 7

How do lymphocytes take care of pathogens

Answer 7

• Every pathogen has unique antigens on its surface
• When lymphocytes come across a foreign antigen, they begin to produce antibodies
• These antibodies lock onto the pathogens and mark them out for destruction by other white blood cells
• More antibidies are then produced to catch out any of the same pathogens
• Memory cells are also produced to create the same antibodies faster if the same pathogen is found again

Question 8

What are the three different types of blood vessels

Answer 8

• Arteries
• Veins
• Capillaries

Question 9

What is the fuction and properties of arteries

Answer 9

• They carry blood away from the heart
• They pump blood at a high pressure, so the artery walls are strong and elastic
• Their elastic fibres allow them to expand
• The walls are thick and the lumen is small

Question 10

What is the function and properties of veins

Answer 10

• They carry blood towards to the heart
• They pump blood at a low pressure
• They have a larger lumen and smaller elastic fibre
• They also have valves to keep blood pumping in the right direction
• Their walls aren’t as thick as the walls of ariteries

Question 11

What is the function and properties of capillaries

Answer 11

• They are used to exchange materials at the tissues
• They are very tiny
• They have permeable walls, one cell thick, to allow diffusion to occure
• They supply food and oxygen and take away waste like CO2