Immune system

Question 1

What is immunity?

Answer 1

the body’s ability to resist foreign organisms and toxins that damage tissues and organs; can be natural or acquired (adaptive)

Question 2

What are leukocytes?

Answer 2

neutrophils, monocytes and macrophages - phagocytosis

Question 3

What are lymphoid organs?

Answer 3

lymph nodes, spleen, thymus gland, tonsils, and adenoids; produce lymphocytes and antibodies

Question 4

What is natural/innate immunity? What are some examples of cells that are a part of natural immunity?

Answer 4

resistance present at birth; not dependent on prior exposure to an antigen

• skin
• phagocytosis
• macrophages
• natural killer cells
• also: inflammatory response! (ex. fever)

Question 5

What are the 2 types of acquired immunity? (cells)

Answer 5

• humoral (B cells)

- cell-mediated (T cells)

Question 6

What is the purpose of humoral immunity?

Answer 6

originate in red bone marrow, B cells produce antibodies after exposure to specific antigens (viruses and bacteria)

Question 7

What happens to a B cell when it becomes activated?

Answer 7

Becomes 2 different cells through division:

• PLASMA cells: produce antibodies called immunoglobulins to block the effect of antigens
• MEMORY cells: stored in the lymph nodes to recognize the antigen if it ever comes back - will transform into plasma cells

Question 8

What are the 3 types of cell mediated immunity?

Answer 8

• cytotoxic T cells: poisons the cell it is attacking
• helper T cells: releases chemicals that attract and activate macrophages to kill cells by phagocytosis
• suppressor T cells: release chemicals to inhibit B and T cells and prevent them from attacking the body’s own good cells

Question 9

What do phagocytes do?

Answer 9

ingest and destroy foreign cells or other harmful substances via phagocytosis

Question 10

What are the 3 types of phagocytes?

Answer 10

• neutrophils: short lived phagocytic cells (eat one bacteria and die, activate at the site of injury)
• monocytes: develop into phagocytic macrophages and migrate to tissues (can travel, larger)
• dendritic cells: often found at or near external surfaces

Question 11

What are the purpose of macrophages and DCs?

Answer 11

they act as antigen-presenting cells by displaying ingested antigens on their outer surface to trigger specific immune cells

Question 12

What does the complement system do?

Answer 12

causes cell lysis by sending salt into the cell, water follows and blows it up

Question 13

What is an allergy?

Answer 13

Abnormal sensitivity acquired by exposure to an antigen. Ranges from:

• allergic rhinitis or hay fever to anaphylaxis
• other topics

Question 14

What is anaphylaxis?

Answer 14

reaction that involves 2 or more body systems. histamine causes the capillaries to become leaky, causing rashes

Question 15

Other allergies:

Answer 15

• atopic dermatitis
• asthma
• urticaria (hives)

Question 16

What is lymphoma? What are the 2 types?

Answer 16

malignant tutor of lymph nodes and lymph tissues

• hodgkin lymphoma (Reed-Sternberg cell, high cure rate, usually young people)
• non-hodgkin lymphoma (older generation typically, follicular lymphoma)