unit 2 test a&p II

Immunity

The ability to
prevent disease
by removing
bacteria, viruses,
toxins and other
foreign materials

Autoimmunity

• An immune
  response against
  one’s own tissues

• Results from the
  failure of the
  immune system
  to discriminate
  between self and
  foreign

Allergy
(Hypersensitivity

An overreaction
to an antigen that
causes injury to
body tissues

antigen

• Molecules that trigger
  specific immune
  responses from the body

• Pathogen = disease
  causing antigen

• Normally the body has
  the ability to recognize
  self-antigens and non-
  self antigens

antibody

• A protein molecule
  produced during specific
  immunity

• Binds to a specific
  antigen and renders it
  harmless = antigen-
  antibody complexes

Immunization

Artificial stimulation of
specific immunity through
the medical introduction of
a harmless antigen into
the body.
• Produces an anamnestic
response

amnestic Response

Specific immune response
that allows the immune
system to remember
antigens it has
encountered in the past
• Essential for a more rapid
defense against previously
encountered antigens if
encountered in the future

Antigenic Determinants

• Lymphocytes interact with specific
  regions of an antigen

• Lymphocytes must interact with
  and recognize an antigen for the
  adaptive immunity response to
  occur

Variable region

part that
combines with the antigenic
determinant of an antigen

Constant region

responsible for
activities of antibodies like
activating complement or attaching
to various WBCs

Antibody Structure

Y-shaped consisting of four
polypeptide chains – two identical
heavy chains and two identical
light chains

lysozyme

Antibacterial enzymes found in body fluids

interferons

antimicrobial proteins made by cells, protect nearby cells from viral infection, regulate activity of immune cells in tumors

histamines & kinins

vasodilation & increased vascular permeability during inflammation

acids

found on the skin surface = acid mantle, stomach and vagina

complement

20 plasma proteins, Become activated when they attach to foreign cells, pokes holes into foreign cells (lyse - burst)

Prostaglandins & Leukotrienes

promote inflammation

pyrogens

promote fever

cytokines

Proteins secreted by cells
that bind to receptors on
cell surfaces
• Stimulate immune
response

other

Digestive enzymes in GI
tract
• Antimicrobial chemicals

Cytotoxic T Cell

Destroy cells by lysis or by producing cytokines

Helper T Cell

Activates B cells and cytotoxic T cells

Regulatory T Cell

Inhibits the actions of B cells, helper T cells, and
cytotoxic T cells

Dendritic Cell

Process (identify) antigens
• Involved in the activation of B cells and T cells

Memory T Cell

Remembers a previously encountered antigen
• Allows for more rapid response if the antigen is
encountered again
• Memory cells are what provide adaptive immunity

Leukocytosis

Tissue injury causes the release of various chemicals that induce
leukocytosis – increased numbers of white blood cells in the
blood stream