Immune Response

Question 1

Define:

Primary Defence

Answer 1

A defence to stop pathogens entering the body

Question 2

List:

The Primary Defences

Answer 2

• Skin
• Blood clots
• Mucous membranes
• Stomach acid
• Expulsive reflex
• Inflammation

Question 3

How does the skin form an effective primary defence?

Answer 3

• Keratinocytes - skin cells form a barrier
• Sebum - sebaceous gland

Question 4

Describe:

Blood Clotting

Answer 4

• Cut in skin - platelets in contact with collagen
• platelets release clotting factors - thromboplastin
• thromboplastin causes prothrombin to become thrombin
• Thrombin causes fibrinogen to become fibrin
• Fibrin forms a mesh to trap red blood cells and platelets
• This forms a scab

Question 5

Name:

Clotting Factor

Answer 5

Thromboplastin

Question 6

Name:

Inactive Proteins

Answer 6

Prothrombin + Fibrinogen

Question 7

What is blood clotting an example of?

Answer 7

• Enzyme cascade
• Primary immune response

Question 8

How is blood supply to a cut reduced?

Answer 8

Seratonin is released - smooth muscle contracts around the arterioles

Question 9

How do mucous membranes form an effective primary defence?

Answer 9

• Produce mucus to trap pathogens
• cilliated cells waft mucus to move it

Question 10

List:

Expulsive Reflexes

Answer 10

• Coughing
• Sneezing
• Vomiting
• Diarrhea

Question 11

Name:

Cells that release histamine

Answer 11

Mast cells

Question 12

List:

Defences of histamine

Answer 12

• localised increase in temperature - kill pathogen
• Vasodilation - More blood - More tissue fluid
• Swelling

Question 13

Define:

Specific defence

Answer 13

• Delayed response compared to primary defence
• Specific to the pathogen

Question 14

What are the two types of specific defense?

Answer 14

• Cell mediated
• Humoral

Question 15

State:

The role of opsonin

Answer 15

• Chemical markers
• Bind to pathogens to increase rate of phagocytosis

Question 16

Name:

The different types of T lymphocyte

Answer 16

• T killer
• T regulator
• T memory
• T helper

Question 17

Name:

The different types of B lymphocyte

Answer 17

• Plasma
• B memory

Question 18

How do autoimmune diseases occur?

Answer 18

• Faulty T Regulator cells
• Body does not recognise cells as self

Question 19

State:

The role of a T Killer cell

Answer 19

• Destroy infected body cells
• Triggered by interferions

Question 20

State:

The role of a T Helper cell

Answer 20

• Release Cytokines
• Interleukins activate B cells

Question 21

Describe:

The structure of antibodies

Answer 21

• Variable region - Complimentary + specific to antigen on specific pathogens
• Constant region - same in all antibodies - complimentary and specific to neutrophil
• Strong disulfide bridges - contail cystine
• hinge region for flexibility
• Multiple variable regions - bind to multiple antigens

Question 22

How does the variable region help the antibody with its function?

Answer 22

• It is complimentary and specific to pathogens
• it can bind to the antigen to block it from binding to a cell
• prevents further infection and reproduction of the pathogen