Lecture 40: Immunology and the Immune System

Question 1

Define the immune system:

Answer 1

• Composed of organs (eg. spleen), cells (eg. T cells), molecules (eg antibodies)
• An organised system of organs, cells, and molecules that interact together to defend the body against disease.

Question 2

Immune system can cause damage to ______ systems.

Answer 2

• Endocrine
• Neurological
• Physiological

Question 3

Organs of the immune system:

Answer 3

• Primary and secondary lymphoid organs
• Primary = production of white blood cells (lymphocytes) usually in thymus or bone marrow
• Secondary = sites where immune responses are initiated (mostly in lymph nodes)

Question 4

What is important about the Thymus?

Answer 4

• “School” for T Cells (white blood cells)
• Developing T Cells learn not to react to self
• Only 10% of T Cells actually leave the Thymus to become a mature T Cell
• If you don’t “pass” there are no second chances, you just die

Question 5

What’s so important about the bone marrow?

Answer 5

• Source of stem cells that develop into cells of the innate’ and ‘adaptive’ immune responses

Question 6

T Cells are made in the _____. B Cells are made in the _____.

Answer 6

• Thymus

- Bone Marrow

Question 7

Lymph nodes are located along _____ ______. Lymph fluid from blood and tissue is _____. This is the site of ______ of immune responses.

Answer 7

• Lymphatic vessels
• Filtered
• Initiation

Question 8

Spleen does not have any _____ ______. It’s there to ______ the blood from blood-borne ______.

Answer 8

• Lymphatic Vessels
• Blood
• Pathogens

Question 9

3 Layers of Immune Defence:

Answer 9

• 1. Physical & Chemical Barriers (Skin, Mucosal Membranes)
• 2. Arm 1: Innate Immune System - rapid, non-specific, fixed
• 3. Arm 2.: Adaptive Immune System - slower, highly specific, adapts

Question 10

Innate Immunity:

Answer 10

• Already in place
• Rapid
• Fixed
• Limited Specificities
• No memory
• Phagocytes
• Complement
• Natural Killer Cells

Question 11

Adaptive Immunity:

Answer 11

• Improves during response
• Slow (days –> weeks)
• Variable
• Highly specific
• Has memory
• B Lymphocytes
• Antibodies
• T Lymphocytes
• Effector T Cells

Question 12

Arms of the immune system both ______ together.

Answer 12

• Work

Question 13

Thucydides:

Answer 13

• @Plague of Athens

- “No one was ever attacked a second time, or not with a fatal result”

Question 14

The development of vaccination:

Answer 14

• China, 10th Century AD: Variolation with Small Pox

- Variolation = giving a purposeful, controlled infection, idea being you don’t get too sick from it

Question 15

Variolation spreads to England:

Answer 15

• Lady Mary Wortley Montague (1700s)

- Brought variolation to England from Turkey

Question 16

The first vaccine for smallpox:

Answer 16

• Benjamin Jesty: Inoculated wife and sons with matter from a cowpox lesion
• Vaccination: Inoculation with an innocuous biological agent

Question 17

Smallpox Vaccination (Edward Jenner):

Answer 17

• Inoculated a boy with a cowpox sore from the hand of a milkmaid
• “In science credit always goes to the person who convinces the world, not the person to whom the idea first occurs”

Question 18

Discovery of cells that eat things:

Answer 18

• Elie Metchnikoff (Late 1800s)
• Discovered phagocytes “devouring cells”
• Put bacteria on starfish larvae, and found that the bacteria was gobbled up
• INNATE IMMUNITY

Question 19

Self/non-self recognition:

Answer 19

• Peter Doherty + Rolf Zinkernagel
• Discovered the cell surface molecules used by the immune system to recognise ‘self’ known as MHC
• ADAPTIVE IMMUNITY