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Chapter 12
The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Fig. 12-CO, p. 406
Immunity
• Body’s ability to resist or eliminate potentially
harmful foreign materials or abnormal cells
• Immune system activities
– Defends against invading pathogens
– Removes “worn-out” cells and tissue damaged by
trauma
– Identifies and destroys abnormal or mutant cells
that have originated in the body
– Mounts inappropriate immune responses that
lead either to allergies or to autoimmune diseases
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Immunity
• Major targets of immune system
– Bacteria
• Non-nucleated, single-celled microorganisms
• Primarily cause tissue damage and cause disease by
releasing enzymes or toxins
– Viruses
• Consists of either DNA or RNA enclosed by a protein
coat
• Cannot carry out metabolism or reproduce without
invading a host cell
• Virulent forms of both bacteria and viruses can
cause disease
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Leukocytes
•
•
Effectors of the immune system
Five types
– Neutrophils
• Highly mobile phagocytes that engulf and destroy unwanted materials
– Eosinophils
• Secrete chemicals that fight parasites
• Involved in allergic reactions
– Basophils
• Release histamine and heparin
• Involved in allergic reactions
– Monocytes
• Transformed into macrophages (tissue-bound phagocytic specialists)
– Lymphocytes
• Β lymphocytes (β cells)
– Transformed into plasma cells that secrete antibodies
• T lymphocytes (T cells)
– Responsible for cell-mediated immunity
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Lymphocytes
• Mainly produced from lymphoid colonies in lymphoid tissues
• Lymphoid tissues
– Tissues that produce, store, or process lymphocytes
– Include
•
•
•
•
•
•
•
•
Bone marrow
Lymph nodes
Spleen
Thymus
Tonsils
Adenoids
Appendix
Peyer’s patches (GALT)
– Gut associated lymphatic tissue
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Table 12-1, p. 409
• Innate (nonspecific) vs. Adaptive (specific)
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Immune Responses
• Innate immune system
– Nonspecific
– Responses work immediately when body is
exposed to threatening agent
– Nonselectively defend against foreign invaders
– First line of defense
– Rapid but limited responses
– Neutrophils, macrophages, several plasma
proteins are important in innate defense
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Immune Responses
• Adaptive or acquired immune system
– Specifically targets foreign material to which body
has already been exposed
– Body has taken time to prepare to attack
– Ultimate weapon against most pathogens
– Responses are mediated by β and T lymphocytes
– Formation of memory cells allows system to react
more swiftly against specific invaders in the future
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity
• Defenses include the following
– Inflammation
– Interferon
– Natural killer cells
– Complement system
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity
• Inflammation
– Nonspecific response to tissue injury
– Ultimate goal is to bring phagocytes and plasma
proteins to invaded or injured area
• Isolate, destroy, or inactivate the invaders
• Remove debris
• Prepare for subsequent healing and repair
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Bacterial invasion
or tissue damage
Release of
histamine
by mast cells
Local arteriolar
vasodilation
Increased local
capillary
permeability
Increased blood
delivery to
injured tissue
Local
accumulation
of fluid
Redness
Heat
Increase in
crucial plasma
proteins, such
as clotting
factors,
in tissue
Swelling
Pain
Increase in
phagocytes
in tissue
Defense against
foreign invader;
tissue repair
Phagocytic
secretions
Systemic responses,
such as fever
Fig. 12-2, p. 411
Innate Immunity
• Inflammation
– Inflammatory response is similar no matter what
the triggering event
•
•
•
•
•
•
•
•
•
Defense by resident tissue macrophages
Localized vasodilation
Increased capillary permeability
Localized edema
Walling-off the inflamed area
Emigration of leukocytes
Leukocyte proliferation
Marking of bacteria for destruction by opsonins
Leukocytic destruction of bacteria
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity (Inflammatory Response)
Phagocyte-Secreted Chemicals
Chemical
Secreted by
Function
Nitric oxide (NO)
Macrophages
Toxic to nearby microorganisms
Lactoferrin
Neutrophils
Protein that binds with iron, making it unavailable for
use by invading bacteria
Histamine
Mast cells
Induces local vasodilation and increases capillary
permeability
Kallikrein
Neutrophils
Converts specific plasma proteins precursors
produced by liver into activated kinins
Endogenous pyrogen
(EP)
Macrophages
Induces development of fever
Leukocyte
endogenous mediator
(LEM)
Macrophages
Decreases the plasma concentration of iron by
altering iron metabolism within the liver, spleen and
other tissues; also stimulates synthesis and release
of neutrophils by the bone marrow
Acute phase proteins
Liver upon
stimulation by
LEM
Play role in inflammatory process, tissue repair, and
immune cell activities
C-reactive protein
Liver
Specific acute phase protein that is clinically used as
a blood-borne marker of inflammation
Interleukin 1 (IL-1)
Macrophages
Enhances proliferation and differentiation of β
and T lymphocytes
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity (Tissue Repair)
• Tissue repair can be perfect
– Cell division replaces lost cells with same kind of
cells
• In nonregenerative tissue (nerve and muscle)
– Lost cells are replaced with scar tissue
• Drugs that suppress with inflammatory process
– Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Aspirin
• Ibuprofen
– Glucocorticoids
• Suppress almost all aspects of inflammatory process
• Reduce body’s ability to resist infection
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity
• Interferon
– Transiently inhibits multiplication of viruses in most cells
– Triggers the production of virus-blocking enzymes by
potential host cells
– Released nonspecifically from any cell infected by a virus
– Provides general, rapid defense until more specific but
slower-responding immune mechanisms can begin
– Enhances macrophage phagocytic activity, stimulates
production of antibodies, boosts the power of killer cells
– Exerts anticancer effects
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity
Mechanism of Action of Interferon in Preventing Viral Replication
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity
• Natural killer (NK) cells
– Naturally occurring lymphocyte-like cells
– Nonspecifically destroy virus-infected cells and
cancer cells
– Mode of action
• Directly lyse cell membranes upon first exposure to
these cells
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity
• Complement system
– Nonspecific response
– Primary mechanism activated by antibodies to kill
foreign cells
– Also activated by exposure to carbohydrate
chains present on surfaces of microorganisms but
not on human cells
– Forms membrane attack complexes that punch
holes in victim cells
– Composed of plasma proteins that are produced
by the liver and circulate in inactive form
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity
• Complement system
– Cascade sequence of events
• C1 is activated → activates C2 → activates C3 →
activates C4 → activates C5
• Components C5 through C9 assemble into large,
doughnut-shaped protein complex (membrane attack
complex – MAC)
– Embeds itself in surface membrane of nearby
microorganisms
– Resulting hole makes membrane leaky
– Victim cell swells and bursts
– Means of killing microbes without killing them
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Innate Immunity
Membrane Attack
Complex (MAC)
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Fig. 12-10, p. 420
Innate Immunity
• Several proteins in complement cascade additionally
augment inflammatory process by
– Serving as chemotaxins
– Acting as opsonins
– Promoting vasodilation and increased vascular
permeability
– Stimulating release of histamine from mast cells
– Activating kinins
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Adaptive Immunity
• Two classes of adaptive immunity
– Antibody-mediated or humoral immunity
• Involves production of antibodies by β lymphocyte
derivatives known as plasma cells
– Cell-mediated immunity
• Involves production of activated T lymphocytes
– Directly attack unwanted cells
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Adaptive Immunity
Origins of β and T Cells
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Adaptive Immunity
• Antigen
– Large, foreign, unique
molecule
– Induces an immune
response against itself
– In general, the more
complex a molecule is, the
greater its antigenicity
• Antibody
– Complex proteins made in B
and T cells that bind to an
antigen in a specific
(adaptive) manner
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
β Lymphocytes: Antibody-Mediated Immunity
• Each lymphocyte has surface receptors for binding
with one particular type of possible antigens
• Antigens stimulate β cells to convert into plasma
cells that produce antibodies
• On binding with processed and presented antigen
– Most β cells differentiate into active plasma cells
– Other β cells become dormant
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Plasma Cells
•
•
•
Produce antibodies that can combine with a specific kind of antigen
All antibodies eventually enter blood where they are known as gamma globulins
or immunoglobulins
Antibody (Immunoglobulin) subclasses
– IgM
• Serves as the β cell surface receptor for antigen attachment
• Secreted in early stages of plasma cell response
– IgG
• Most abundant immunoglobulin in blood
• Produced in large amounts when body is exposed to same antigen
– IgE
• Helps protect against parasitic worms
• Antibody mediator for common allergic responses
– IgA
• Found in secretions of digestive, respiratory, and genitourinary systems; also in
milk and tears
– IgD
• Present on surface of many β cells
• Function is uncertain
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Antibodies
• Y-shaped molecules
• Composed of four interlinked
polypeptide chains
– Two long, heavy chains
and two short, light chains
• Properties of tail portion
determine functional properties
of the antibody
• Identical antigen-binding
fragments (Fab) at tip of each
arm (unique for each different
antibody)
• Tail (constant region) regions
within each subclass are
identical
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Antibodies
• Can physically hinder antigens
• By neutralization, they prevent harmful chemicals
from interacting with susceptible cells
• Can bind to foreign cells by agglutination
• Enhance activity of other defense systems by
– Activating complement system
– Enhancing phagocytosis
– Stimulating killer (K) cells
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Fig. 12-10a, p. 420
B cell specific to antigen
Different
B cell clones
Antigens
Rough
endoplasmic
Plasma cells
reticulum
Memory cells
Antibodies
Fig. 12-11, p. 421
Β Lymphocytes
• Activated β-cell clones multiply and differentiate into
– Plasma cells
• Produce and secrete IgG antibodies
• Antibody combines with an antigen, marking it for destruction
• During initial contact with microbial antigen, antibody
response is delayed and plasma cells are formed
• Peak is reached in a couple of weeks by primary response
• After peak, antibody concentration decreases
– Memory cells
• Small percentage of β lymphocytes become memory cells
• Remain dormant
• Upon reexposure to same antigen, they are more ready for
immediate action than the original lymphocytes of the clone
• Secondary response is quicker, more potent, and longerlasting
– Can be induced by disease or vaccination
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Primary and Secondary Immune Responses
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
First exposure to
a pathogen’s antigens
Natural exposure
to virulent, antigenic
pathogen
Virulent portion
Exposure to nonvirulent,
antigenic pathogen
through vaccination
Antigenic portion
No
virulence
Combat
Disease
Specific B cell clone
Specific B cell clone
No disease
Plasma
cells
Memory cells
(long-term
immunity)
Memory cells
(long-term
immunity)
Plasma
cells
Antibodies
(slow, weak
primary response)
Antibodies
(not needed)
Subsequent exposure to
same virulent pathogen
Plasma
cells
Plasma
cells
Combat
Combat
Antibodies
(swift, strong
secondary response)
No disease
Antibodies
(swift, strong
secondary response)
Fig. 12-13, p. 423
Active and Passive Immunity
• Active immunity
– “self-generated”
– Results from exposure to an antigen
• Passive immunity
– “borrowed immunity”
– Results from transfer of preformed antibodies
– Can provide immediate protection or bolster
resistance
– Example of passive immunity is transfer of IgG
antibodies from mother to fetus
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Antigen Presentation
• Lymphocytes respond only to antigens presented to them by
antigen-presenting cells
– Macrophages can be antigen-presenting cells
• Cluster around appropriate β-cell clone
• Phagocytosis occurs, processing the raw antigen
intracellularly and presenting the processed antigen,
exposing it to the outer surface of the macrophage’s plasma
membrane
• As macrophage engulfs and ingests microbe, it digests the
microbe into antigenic peptides
• Antigenic peptides bind to a MHC molecule which transports
the bound antigen to the cell surface where it is presented to
passing lymphocytes
• Antigen-presenting macrophages secrete interleukin
– Enhances differentiation and proliferation of now-activated βcell clone
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
T Lymphocytes
• Carry out cell-mediated immunity
• Do not secrete antibodies – directly bind to targets
• Killer T cells release chemicals that destroy targeted
cells
• Clonal and antigen specific – acquire receptors in
the thymus
• T cells are activated for foreign attack only when it is
on the surface of a cell that carries foreign and self
antigens
• Learn to recognize foreign antigens only in
combination with a person’s own tissue antigens
• A few days are required before T cells are activated
to launch a cell-mediated attack
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
T Lymphocytes
• Two main types of T cells
– CD8 cells (cytotoxic, or killer T cells)
• Destroy host cells harboring anything foreign
– CD4 cells (mostly helper T cells)
• Modulate activities of other immune cells
• Secrete chemicals that amplify the activity of other
immune cells
– Β-cell growth factor
– T-cell growth factor (interleukin 2)
– Macrophage-migration inhibition factor
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Invading bacteria
Macrophages secrete
interleukin 1, which
enhances B cell
proliferation and
antibody secretion
Macrophages “process and present”
bacterial antigen to B and T
lymphocyte clones specific to
the antigen
Interleukin 1
Antibodies enhance
phagocytosis by
coating the bacteria
and serving as
opsonins
Macrophage
B cell
Helper T cell
Activated helper T cell
B cell growth
factor
Helper T cells secrete B cell
growth factor that enhances B
cell proliferation and antibody
secretion
Plasma cell
Plasma cells secrete antibodies
that bind with the
antigenic bacteria
Antibodies
Fig. 12-15, p. 427
Fig. 12-17, p. 430
Mechanism of
Killing by Killer
Cells
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Fig. 12-20, p. 435
Fig. 12-23, p. 437
Cytotoxic T cell
T cell receptor
Foreign antigen
MHC self-antigen
Invaded cell
Fig. 12-19, p. 434
Innate and Adaptive Responses to Bacterial Infection
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Β versus T Lymphocytes
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Immune System Tolerance
• Tolerance refers to preventing the immune system
from attacking the person’s own tissues
• Mechanisms involved in tolerance
– Clonal deletion
– Clonal anergy
– Receptor editing
– Inhibition by regulatory T cells
– Immunological ignorance
– Immune privilege
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Autoimmune Diseases
• Arise from loss of tolerance to self-antigens
• Examples of causes
– Exposure of normally inaccessible self-antigens
sometimes induces an immune attack against these
antigens
– Normal self-antigens may be modified by factors such as
drugs, environmental chemicals, viruses, or genetic
mutations so that they are no longer recognized and
tolerated by the immune system.
– Exposure of the immune system to a foreign antigen
structurally identical to a self-antigen
– May be related to pregnancy, arising from lingering fetal
cells in the mother’s body after the pregnancy
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Self-antigens
• Plasma membrane-bound glycoproteins called MHC
molecules
• Synthesis is directed by group of genes called major
histocompatibility complex (MHC)
• Exact pattern of MHC molecules varies from one
individual to another
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Immune Surveillance
• Process by which T cells recognize and destroy
newly arisen, potentially cancerous tumor cells
• Tumor
– Clone of cells identical to original mutated cell
• Benign tumor
– Does not infiltrate surrounding tissues
• Malignant tumor
– Invasive and cancerous
– Cells tend to metastasize
– May spread throughout body and cannot be removed
surgically
• Untreated cancer is eventually fatal
• Most genetic mutations do not lead to cancer
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Immune Surveillance Against Cancer
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Immune Diseases
• Due to abnormal functioning of the immune system
• Two general ways
– Immunodeficiency diseases
• Too little immune response
• Examples
– severe combined immunodeficiency
– AIDS
– Inappropriate immune attacks
• Too much or mistargeted immune response
• Categories of inappropriate attacks
– Autoimmune responses
– Immune complex diseases
– Allergies
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Allergy
• Acquisition of an inappropriate specific immune
reactivity (hypersensitivity) to a normally harmless
environmental substance
• Offending agent is known as an allergen
• Categories of allergic responses
– Immediate hypersensitivity
– Delayed hypersensitivity
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Fig. 12-24, p. 440
Comparison of Immediate and Delayed
Hypersensitivity Reactions
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Immediate Hypersensitivity
• Chemical mediators
– Histamine
– Slow-reactive substance of anaphylaxis (SRS-A)
– Eosinophil chemotactic factor
• Symptoms
– Vary depending on site, allergen, and mediators
involved
• Hay fever
• Asthma
• Hives
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
External Defenses
• Most obvious external defense is the skin, or
integument
• Consists of two layers
– Epidermis
• Outer, vascular, keratinized layer
– Dermis
• Inner, connective tissue layer
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Anatomy of the Skin
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Epidermis
• Four cell types
– Melanocytes
• Produce melanin which protects the skin by absorbing
harmful UV radiation
– Keratinocyes
• Produce keratin that forms outer protective layer of skin
• Discourages bacteria and other harmful environmental
agents from entering body
• Prevents loss of water and other valuable body substances
• Secrete interleukin 1
– Langerhans cells
• Function in specific immunity by presenting antigen to helper
T cells
– Granstein cells
• Suppress skin-activated immune responses
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Dermis
• Contains
– Blood vessels
• Nourish the skin
• Play role in regulating body temperature
– Sensory nerve endings
• Provide information about the external environment
– Several exocrine glands and hair follicles
• Sebaceous glands
– Produce sebum
– Oily substance that softens and waterproofs the skin
• Sweat glands
– Produce sweat which helps cool the body
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Additional Defenses
• Additional protective measures guard against entry
of potential pathogens through internal cavities that
communicate directly with the external environment
– Digestive system
•
•
•
•
Antimicrobial salivary enzyme
Destructive acidic gastric secretions
Gut-associated lymphoid tissue
Harmless resident colonic secretions
– Genitourinary system
• Destructive acidic and particle-entrapping mucus
secretions
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Additional Defenses
– Respiratory system
• Alveolar macrophage activity
• Secretion of sticky mucus that traps debris which is
swept out by ciliary action
• Nasal hairs filter out large inspired particles
• Reflex cough and sneeze mechanisms expel irritant
materials from trachea and nose
• Tonsils and adenoids defend immunologically
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Blood Groups
• Form of passive immunity
• ABO blood types are named for presence of antigens on
surface of erythrocytes
– Type A has A antigens and anti-B antibodies
– Type B has B antigens and anti-A antibodies
– Type AB has both A and B antigens and no
antibodies related to the ABO system
– Type O does not have A or B surface antigens and
both anti-A and anti-B antibodies
• Transfusion reaction occurs when blood of incompatible
type is given
• Blood type O is the universal donor
• Blood type AB is the universal recipient
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Transfusion Reaction
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Other Blood Group Systems
• Rh factor
– Rh-positive individual has Rh factor
– Rh-negative individual lacks Rh factor
– Erythroblastosis fetalis (hemolytic disease of the
newborn)
• Occurs when Rh-negative mother develops antibodies
against the erythrocytes of an Rh-positive fetus
• Approximately 12 other minor human erythrocyte
antigen systems
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning
Chapter 12 The Body Defenses
Human Physiology by Lauralee Sherwood ©2007 Brooks/Cole-Thomson Learning