Lines of Defence 2: Inflammation

Question 1

Identify and describe an antibody:

Answer 1

A protein made by plasma cells (a type of white blood cell) in response to an antigen (a substance that causes the body to make a specific immune response).

Question 2

Identify the signs of a simple infection. What are the symptoms, and how do they affect the person?

Answer 2

The affected area becomes red, warm and swollen. This is a sign of inflammation, which is part of the second line of defence. Blood flow to the affected area is increased and the blood vessels become more permeable (‘leaky’).
Fever is also part of the second line of defence. Normal body temperature is about 37 °C. A temperature over 37.8 °C is considered to be a fever and indicates an infection.

Question 3

the sequence of steps involved in an antibody response, from invasion to elimination:

Answer 3

The small clump of bacteria releases a chemoattractant that is sensed by the neutrophil. The neutrophil becomes polarised and starts chasing the bacteria. The bacteria is bounced around by thermal energy which moves in a random path, seeming to avoid neutrophils. Eventually the neutrophil catches up with the bacteria and engulfs them by phagocytosis.

Question 4

What is a neutrophil?

Answer 4

Neutrophils are white blood cells which hunt and kill bacteria.

Question 5

What is a Mast Cell?

Answer 5

Mast Cells produce histamine, which causes blood vessels to dilate (expand)

Question 6

What are Macrophage/Phagocytes?

Answer 6

It’s a white blood cell, which consumes pathogens.

Question 7

What does the immune system do?

Answer 7

The immune system works to keep us healthy from pathogens

Question 8

What cells does the 2nd line of defence include?

Answer 8

It includes Mast Cells, and Macrophages (they are both non-specific)