chapter 16 altered immune response and transplantation - week 1

Question 1

What are lymphocytes and how are they produced?

Answer 1

They are produced in the bone marrow and will eventually migrate to the peripheral organs

Question 2

What occurs during the immune response on a cellular level (ex lymphocytes, monocytes, white blood cell involvement)

Answer 2

• A virus invades the body through a break in the skin or another portal of entry. Thevirus must make its way inside a cell in order to replicate itself.
• macrophage recognizes the antigens on the surface of the virus.The macrophage digests the virus and displays pieces of the virus (antigens) on its surface.
• T helper cells recognize the antigen displayed and bind to the macrophage. This binding stimulates the production of cytokines (IL-1, TNF) by the macrophage and interleukin-2 (IL-2) and γ-interferon (γ-IFN) by the T helper cells. These cytokines are intercellular messengers that provide communication among the cells.
• IL-2 instructs other T helper cells and T cytotoxic cells toproliferate (multiply). T helper cells release cytokines, causing B cells to multiply and produce antibodies.
• T cytotoxic cells and natural killer cells destroy infected body cells.
• The antibodies bind to the virus and mark it for macrophage destruction.
• Once the virus is gone, activated T and B cells are turned off by suppressor T cells. Memory B and T cells remain behind to respond quickly if the same virus attacks again.
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Question 3

humoral vs cell-mediated immunity

Answer 3

Humoral immunity is antibody-mediated immunity. While cell mediated is an immune response that is initiated through specific antigen recognition by T cells

Both of these are types of adaptive immunity, however, cell-mediated immunity involves the initial identificaiton of an unknown pathogen, while humoral immunity requires prior exposure to the antigen.

Question 4

What is a hypersensitivity reaction? What are the 4 types? When does each occur and how is it different from the normal response?

Answer 4

Sometimes the immune response is over active against foreign antigens or reacts against its own tissue, resulting in tissue damage. This is termed a hypersensitivity reaction.
Type I- Anaphylactic (allergies, asthma)
Type II - Cytotoxic Reaction (trasnfusion reaction, goodpasture’s syndrome)
Type III- Immune complex reactions (Serum sickness, systemic lupus, erythematosus, rheumatoid arthritis
Type IV- Delayed hypersentsitivitey reactions (contact dermatitis, tumour rejection, transplant rejection)

Question 5

autoimmunity

Answer 5

Autoimmunity is an immune reaction to self-proteins: the immune system no longer differentiates self from nonself. For unknown reasons, immune cells that are normally unresponsive (tolerant of self-antigens) are activated. In autoimmunity, autoantibodies and auto sensitized T cells cause pathophysiological tissue damage

Question 6

what immune mechanisms are impaired in immunodeficiency ?

Answer 6

Immunodeficiency disorders involve impairments of one or more immune mechanisms, which include:
* phagocytosis,
* humoral response
* cell-mediated immune response,
* Complement
* a combined humoral and cell-mediated deficiency.
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Question 7

anergy

Answer 7

an immunodeficient condition characterized by lack of or diminished reaction to an antigen or a group of antigens

Question 8

antigen

Answer 8

is a substance that elicits an immune response.

Question 9

apheresis

Answer 9

is a procedure in which components of the blood are separated and then one or more of those components is removed.

Question 10

autoimmunity

Answer 10

Autoimmunity is an immune reaction to self-proteins: the immune system no longer differentiates self from nonself.

Question 11

cell-mediated immunity

Answer 11

Immune responses that are initiated through specific antigen recognition by T cells

Question 12

cytokines

Answer 12

soluble factors secreted by WBCs and a variety of other cells in the body which act as messengers between the cell types. Cytokines instruct cells to alter their proliferation, differentiation, secretion, or activity. human leukocyte antigen (HLA) system,

Question 13

hypersensitivitey reaction

Answer 13

Sometimes the immune response is overreactive against foreign antigens or reacts against its own tissue, resulting in tissue damage. This is termed a hypersensitivity reaction.

Question 14

immunity

Answer 14

is the body’s ability to resist disease.

Question 15

immuno-competence

Answer 15

is the state in which the body’s immune system can identify and inactivate or destroy foreign substances.

Question 16

immunodeficiency

Answer 16

The condition in which the immune system does not adequately protect the body is immunodeficiency.