Blood and Body Defences

Question 1

How does the skin act as a defence against disease?

Answer 1

dry dead cells act as a physical barrier and sweat glands produce oils that help to kill microbes

Question 2

How does stomach acid act as a defence against disease?

Answer 2

kills pathogens present in food and drink, protein digestion, activates pepsin

Question 3

How does cilia and mucus act as a defence against disease?

Answer 3

goblet cells produce sticky mucus which traps microbes, cilia then move the mucus up to swallow

Question 4

How do nasal hairs act as a defence against disease?

Answer 4

keep out dust and larger microbes

Question 5

How do tears acta as a defence against disease?

Answer 5

contain lysozymes (bacteria destroying enzymes)

Question 6

What are platelets?

Answer 6

tiny cell fragments in the blood

Question 7

Explain how scabs help

Answer 7

prevent microbes entering the skin and stops you from losing to much blood

Question 8

What are the 2 white blood cells the immune system is made up of?

Answer 8

lymphocytes and phagocytes

Question 9

What do phagocytes do?

Answer 9

carry out phagocytosis (engulf pathogens), contain and produce enzymes that digest and breakdown the pathogen so that it is no longer harmful

Question 10

What do lymphocytes do?

Answer 10

produce antitoxins and antibodies

Question 11

What are antibodies?

Answer 11

proteins that bind to the pathogens antigens on its cell surface membrane

Question 12

What do the lymphocyte and phagocyte do in an immune response to a pathogen?

Answer 12

lymphocyte produces antibody which binds to antigens of pathogen. Phagocyte then comes in, engulfs and destroys pathogen

Question 13

antigens and antibodies are

Answer 13

complementary

Question 14

What are the cells that store info on antigens and antibodies to help destroy pathogens?

Answer 14

B memory cells