Neurobiology and Immunology: Non-Specific Body Defences

Question 1

What is a pathogen?

Answer 1

A bacterium, virus or other organism that can cause disease

Question 2

Non-specific defences can be what?

Answer 2

Physical and chemical

Question 3

Epithelial cells do what?

Answer 3

Form a physical barrier

Question 4

Closely packed epithelial cells are found where?

Answer 4

In the skin and inner linings of the digestive and respiratory systems

Question 5

What are chemical secretions and what do they do?

Answer 5

Chemical secretions such as tears, saliva, mucus and stomach acid are produced against invading pathogens

Question 6

What is the inflammatory response?

Answer 6

A defence mechanism triggered by damage to living tissue

Question 7

Histamine is released by what? What does it do?

Answer 7

Mast cells.
Causes vasodilation and increased capillary permeability. The increased blood flow leads to an accumulation of phagocytes and clotting elements at the site of infection

Question 8

What do phagocytes do?

Answer 8

Recognise pathogens and destroy them by phagocytosis

Question 9

What does phagocytosis involve?

Answer 9

The engulfing of pathogens and their destruction by digestive enzymes containing lysosomes

Question 10

What do phagocytes release?

Answer 10

Cytokines which attract more phagocytes to the site of infection

Question 11

What are cytokines?

Answer 11

Cytokines are protein molecules that act as a signal to specific white blood cells, causing them to accumulate at the site of infection