Immune System

Question 1

What are the two major immune responses?

Answer 1

• Cell-mediated response (T-lymphocyte driven)

- Humoral response (B-lymphocyte driven)

Question 2

Where do B and T lymphocytes originate from?

Answer 2

Both originate from bone marrow, T-lymphocytes mature in the thymus gland with macrophage assistance.

Question 3

How do B-lymphocytes act?

Answer 3

They secrete antibodies (aka immunoglobulins), which can specifically attack an antigen.

Question 4

What are six ways that antibodies and other complement proteins can attack antigen bearing particles?

Answer 4

• Lysis (digesting plasma membrane)
• Opsonization (make plasma membrane susceptible to phagocytosis)
• Agglutination (clumping of antigen bearing cells)
• Chemotaxis (attracting other cells (ie. phagocytes) to the area
• Inflammation (migration of cells, release of fluids and dilation of blood vessels)

Question 5

What is an activated antibody secreting B-lymphocyte called?

Answer 5

Plasma cells

Question 6

True or false? Both T and B lymphocytes produce memory cells

Answer 6

true!!

Question 7

What are the lymphatic organs?

Answer 7

• Lymph nodes
• Thymus
• Spleen

Question 8

In addition to being the place where T-lymphocytes mature, what does the thymus do to promote T-lymphocyte activity?

Answer 8

Secretes thymosin

Question 9

What are two general functions of lymph nodes?

Answer 9

• Non-specific filtration of bacteria and other particles from the lymph using the phagocytic activity of macrophages
• The storage and proliferation of T-cells, B-cells and antibody production

Question 10

What do the two components of the spleen do?

Answer 10

White pulp

• Filter damaged RBCs
• Filter cellular debris
• Filter foreign particles from the blood

Red Pulp
- Store erythrocytes

Question 11

Superantigens bind with 20% of T lymphocytes that they are presented to. Conventional antigens bind with about 1 in 100,000 T cells.

Superantigens increase the number of activated T cells over conventional activation levels by a factor of ___?

Answer 11

20,000

Taking 20% of 100,000 yields 20,000