Lecture 7 - Vertebrate Immune System

Question 1

What is Innate Immunity?

Answer 1

-In all animals
- Recognition of traits shared by broad ranges of pathogens, using a small set of receptors
- Rapid response

Question 2

What is Adaptive Immunity?

Answer 2

• Vertebrates only
• Recognition of traits specific to particular pathogens, using a vast array of receptors
• Slower response

Question 3

What is Barrier defense?

Answer 3

-Innate Immunity
- Skin, Mucous membranes, Secretions

Question 4

Internal defense?

Answer 4

• Innate Immunity
• Phagocytic cells
• Natural killer cells
  -Antimicrobial proteins
  -Inflammatory response

Question 5

Humoral response

Answer 5

-Adaptive Immunity
- Antibodies defend against infection in body fluids

Question 6

Cell-mediated response

Answer 6

• Adaptive Immunity
• Cytotoxic cells defend against infection in body cells

Question 7

How does skin/shells/cuticles prevent pathogens?

Answer 7

• Innate immunity
  -Barrier defense
  Thickened outer surface inhibits entry by pathogens

Question 8

How does the mucous membranes prevent pathogens entering the body?

Answer 8

• Innate immunity
• Barrier defense
  Mucus secreted by internalized external surfaces trap microbes and other particles

Question 9

How does Secretion prevent pathogens entering the body?

Answer 9

-Innate Immunity
- Barrier defense
-Saliva, tears
Washing action prevents microbial colonization
Hostile chemical environment - Lysozyme, acidic pH

Question 10

How do Phagocytotic cells work?

Answer 10

• Internal defense
• Recognizes molecules characteristic of a set of pathogens
• That recognized molecule is absent from vertebrates and is an essential component of certain groups of pathogens

Question 11

What do Phagocytotic cells do?

Answer 11

Destroy pathogens using phagocytosis

Question 12

Where are Phagocytic cells located?

Answer 12

Blood, Skin, Mucous membranes, Lymph

Question 13

What is in the Lymphatic system?

Answer 13

• Thymus
• Spleen
• Lymph nodes
• Appendix
• Peyer’s patches
• Lymphatic vessels
• Adenoid
• Tonsils

Question 14

How do Natural Killer Cells work?

Answer 14

Recognize surface proteins of virus-infected or cancerous cells
- Internal Defense

Question 15

What do Natural Killer Cells do?

Answer 15

Release chemicals that cause apoptosis (cell death) in infected or cancerous cells
- Internal defense

Question 16

What do Antimicrobial Proteins do?

Answer 16

• Attack pathogens or impede their reproduction
• Eg Interfons or Complement Proteins
• Internal defense

Question 17

Interferons

Answer 17

-Are secreted by virus-infected cells
-Trigger surrounding cells to produce chemicals that inhabit viral reproduction
- Internal defense

Question 18

Complement Proteins

Answer 18

• Are plasma proteins activated by substances on the surface of many microbes
  -Lead to lysis of invading cells
• Also involved in inflammation and in adaptive immunity
• internal defense

Question 19

Inflammatory response

Answer 19

-Signaling molecules released by injured or infected tissue causes local inflammation
-E.g. Histamine, Cytokines
- Internal Defense

Question 20

Cytokines

Answer 20

• further increases blood flow to the affected area

Question 21

Histamine

Answer 21

• Triggers vasodilation and increased blood vessel permeability in affected areas
  -More white blood cells and proteins can enter interstitular fluid
• Internal Defense

Question 22

Systemic inflammatory response

Answer 22

• Release more white blood cells from the bone marrow
• Reset body’s thermostat to cause fever

Question 23

What is pathogen-specific recognition?

Answer 23

Specificity is achieved through interaction between antigens and antigen receptors

Question 24

Antigen definition

Answer 24

Large molecules found on the surface of specific pathogens or secreted by those pathogens

Question 25

Antigen receptors defintion

Answer 25

Protein receptors are protein produced by B cells or T cells

Question 26

What are epitopes?

Answer 26

A small, accessible portion of an antigen that binds to an antigen receptor
- Multiple are contained in each antigen

Question 27

What are lymphocytes?

Answer 27

White blood cells produced in the bone marrow
- B cell and T cells are lymphocytes

Question 28

What are B-cells?

Answer 28

-Matures in the bone marrow
- Is a lymphocyte
- Produces a single type of antigen receptor
- Each antigen receptor binds to a single epitope of a single antigen

Question 29

What is a T cell?

Answer 29

• Migrates to the thymus for maturation
• Is a lymphocyte
• Produces a single type of antigen receptor
• Each antigen receptor binds to a single epitope of a single antigen

Question 30

What do Variable regions do?

Answer 30

They are parts of antigen receptors, and produce the specificity of the antigen-binding site