Immunoglobulins and Hypersensitivity

IgA

most abundant in body secretions

IgD

Low concentration in blood; are surface receptors on developing B Lymphocytes

IgE

Active against parasites; are important mediators of allergic responses

IgG

Most abundant class of Igs; are transported across the placenta; single molecule

IgM

Produced during the primary response to antigen; are thee largest Igs (pentamer); cannot penetrate vascular wall; Found on B cell surface

What immune cells are present in skin and mucous ?

monocytes and macrophages

What immune cells are present in Bone marrow?

B lymphocytes and leukocytes

What immune cells are present in the thymus?

T lymphocytes

What immune cells are present in tonsils, spleen and lymph nodes?

B lymphocytes and T lymphocytes

What immune cells are present in Peyer patches?

primarily B lymphocytes

Type I hypersensitivity

an immediate allergic or anaphylactic type of reaction mediated primarily by sensitized mast cells.

What are the symptoms of anaphylaxis?

vascular permeability, vasodilation, hypotension, urticaria, and
bronchoconstriction

Type II hypersensitivity

antibodies are formed against antigens on cell surfaces (cytotoxic) resulting in lysis of target cells: mediated by
activated complement fragments or by phagocytic cells

Type III hypersensitivity

antigen-antibody complexes are deposited in tissues which activate the complement cascade attracting phagocytic cells to the
tissue

Type IV hypersensitivity

T-cell–mediated and do not require antibody production.

Sensitized T cells react with altered or foreign cells and
initiate inflammation