Immune System

Question 1

What is an antigen?

Answer 1

An antigen is any cell or substance that stimulates an immune response.

Question 2

What are antigens?

Answer 2

Antigens are toxins, chemicals, bacteria, viruses or other substances from outside the body.

Question 3

What is a non-specific defence?

Answer 3

Epithelial barriers
Phagocytes
Antimicrobial chemicals
Inflammatory response
Immunological surveillance

Question 4

What are the two defence mechanisms?

Answer 4

Non-specific and specific

Question 5

What are examples of a non-specific mechanisms?

Answer 5

Cells, chemicals and physical barriers that are present at birth.

Question 6

What are examples of a specific mechanisms?

Answer 6

Activated by the presence of microbes.
Collection of organs, cells and chemicals that generate cells and antibodies for a specific target

Question 7

what are Epithelial barriers?

Answer 7

Healthy, intact skin:
- Bacteria
- Sebum and sweat contain antibacterial and antifungal substances.
- Epithelial membranes
- Nose hairs
- Urine flow and vaginal secretions

Question 8

what are phagocytes? And what do they do?

Answer 8

-Neutrophils and macrophages. WBC.
Migrate to inflammation and infection - engulf, digest and destroy foreign, antigenic and damaged body cells.

Question 9

What happens to neutrophils when they are activated and phagocytosing?

Answer 9

Destroy themselves and their target.

Question 10

Macrophages (WBC) what are they and what do they do?

Answer 10

• Longer lifespan than neutophils.
• Response to an infection.
• After destroying the antigen they display fragments to stimulate T cells
• Promote inflammatory response, induce fever and healing.

Question 11

Name all 6 antimicrobial chemicals?

Answer 11

Hydrochloric acid
Lysozyme
Antibodies
Saliva
Interferons
Complement (plasma proteins)

Question 12

Hydrochloric acid

Answer 12

• Present in gastric juice
• It kills swallowed microbes.
• pH is 1 - 2
• Some meds can reduce acidity which makes someone more susceptible to GI infections.

Question 13

Lysozyme

Answer 13

• Antibacterial enzyme
• Found in granulocytes
• NOT found in sweat, urine or CSF (fluid in the brain)
• Destroys bacterial cell wells.

Question 14

What are the 3 granulocytes?

Answer 14

Basophil, Neutrophil and Eosinophil

Question 15

Antibodies

Answer 15

• Protective proteins
• Bind to destroy antigens
• Found in all body fluids
• Coat membranes that are exposed to external environment; Genitourinary tract, respiratory tract and GI tract.

Question 16

Saliva

Answer 16

• Secreted into the mouth
• Washes away food debris - could encourage bacterial growth.
• Contains antibodies.

Question 17

Interferons

Answer 17

• Produces and released into local tissues by T cells, macrophages and virus infected body cells.
• Reduce the spread of viruses to healthy body cells.

Question 18

Complement

Answer 18

• about 20 proteins found in blood and tissues.
• Activated by immune complexes (antibody + antigen)
• Destroys bacteria
• Stimulates phagocytosis.
• Chemoattractant

Question 19

What is the purpose of Inflammatory response? signs of inflammation?

Answer 19

Purpose is protective, help healing. Signs are, redness, heat, swelling and pain.

Question 20

What is acute inflammation? what are the effects?

Answer 20

Short duration.
Effects:
- Increased blood flow
- Tissue fluid
- Migration of WBC
- Raised temp
- Pain
- Suppuration (pus)

Question 21

What are immunological surveillance

Answer 21

Lymphocytes

Question 21

What are immunological surveillance

Answer 21

Lymphocytes