Download 14-1 Checkpoint - Jordan High School

Chapter 14
The Lymphatic System
& Immunity
14 - 1
14-1: Anatomical Barriers
Pathogen—microorganisms that cause
disease
Lymphatic system—cells, tissues, organs
responsible for defending the body
Immunity—ability to resist infection &
disease
Innate (nonspecific) immunity protects against
any pathogen
Adaptive (specific) immunity attack specific
pathogens
14-1 Checkpoint
1. Define pathogen.
2. Explain the difference between nonspecific
and specific defense.
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14-2: Lymphatic System
Functions of the Lymphatic System
Produce, maintain & distribute lymphocytes
Most live many years
Return fluids from peripheral tissues to the
bloodstream
Distribute hormones, nutrients, wastes from
tissues to bloodstream
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Lymphatic Vessels
Carry lymph (tissue fluid) to venous system
Lymph contains fluids, solutes, pathogens
Lymphatic
capillaries 
lymphatic vessels
lymphatic
ducts
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14 - 6
Lymphocytes
T cells (most lymphocytes)
Cytotoxic T cells directly attack foreign cells or
virus-infected cells (provides cellular immunity)
Helper T cells stimulate T cells & B cells
Suppressor T cells inhibit T cells & B cells
B cells secrete antibodies that bind to
specific antigens (provides humoral
immunity)
NK cells attack foreign cells, cancer cells
Lymphoid Nodules
Lymphoid nodules increase/decrease in
size depending on number of lymphocytes
present (ex: tonsils)
Lymphoid Organs
Lymph nodes defend against bacteria &
other invaders
Thymus produces T cells
Spleen filters blood, initiates B cell & T cell
responses
14-2 Checkpoint
1. List the components of the lymphatic
system.
2. How would blockage of lymphatic ducts
affect the circulation of lymph?
3. If the thymus gland failed to produce thymic
hormones, which population of lymphocytes
would be affected?
4. Why do lymph nodes enlarge during some
infections?
14-3: Innate (Nonspecific)
Defenses
Deny entry or limit the spread of
microorganisms or other hazards
Physical Barriers
Keep hazardous organisms & materials from
entering the body
Skin, mucous membranes, hair, sweat
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Phagocytes
Phagocytes attack & remove
microorganisms
Microphages & macrophages engulf invading
pathogens
Immunological Surveillance
Immunological surveillance monitors
normal tissues & attacks abnormal cells (uses
NK cells)
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Interferons
Interferons released by lymphocytes to
interfere with viral replication in cells
Inflammation
Inflammation—localized tissue response to
injury
Tissue damage  mast cells release
histamine & heparin  redness, heat,
swelling & pain  tissue repair
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Fever
Fever increases body temperature
Benefits: increases metabolism, cells move
faster, enzyme reactions proceed quicker,
bacteria inactivated
Problems: high fevers damage body systems,
damage nervous tissue, seizures
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14-3 Checkpoint
1. List the body’s nonspecific defenses.
2. A rise in the level of interferon in the body
indicates what type of infection?
3. What effects does a fever have on the body?
14-4: Adaptive (Specific)
Defenses
Respond to presence of specific antigens
T cells defend against abnormal cells &
pathogens (cell-mediated immunity)
B cells defend against antigens & pathogens
(antibody-mediated immunity)
Types of Immunity
Innate immunity present at birth
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Adaptive immunity acquired by active or
passive means
Active immunity appears after exposure to an
antigen
• Naturally acquired active immunity—exposure to
antigens in environment
• Artificially induced active immunity—develops after
immunizations (vaccinations)
Passive immunity produced by the transfer of
antibodies
• Naturally acquired passive immunity—mother’s breast
milk
• Artificially induced passive immunity—antibodies given
after pathogen exposure
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Benefits of vaccines
Spare the symptoms & discomfort of disease
Booster shots intensify immune response
Wiped out/lessened effects of some diseases
Problems of vaccines
Cellular memory poorly established
Can cause the disease the vaccine is trying to
prevent
14-4 Checkpoint
1. Distinguish between cell-mediated (cellular)
immunity & antibody-mediated (humoral)
immunity.
2. Identify the two forms of active immunity &
the two types of passive immunity.
3. List the four general properties of adaptive
immunity.
14-6: Antibodies & Antigens
Primary & Secondary Responses to
Antigen Exposure
Primary response—body’s initial response
to antigen exposure
Takes time to develop (1 – 2 weeks)
Secondary response—exposure to same
antigen triggers release of memory cells
Faster response than primary response
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14-6 Checkpoint
1. How does an antigen differ from an
antibody?
2. Distinguish between the primary and
secondary responses to an antigen.
14-7: Abnormal Immune
Responses
Autoimmune Disorders
Autoimmune disorders—immune response
mistakenly targets normal body cells &
tissues
Rheumatoid arthritis (RA), type 1 diabetes
Immunodeficiency Diseases
 Immune system fails to develop or is
blocked
 AIDS
Allergies
Allergies—inappropriate/excessive response
to antigens
Triggered by allergens
Immediate hypersensitivity—rapid &
severe response to antigen
First exposure does not produce reaction
Second exposure causes inflammation response
Anaphylaxis—allergen affects cells
throughout body; causes swelling, hives
Severe cases can be fatal
Cytotoxic reactions occur following
incompatible blood transfusion
Delayed hypersensitivities occur 2 – 3 days
after exposure (poison ivy)
Many signs & symptoms of hypersensitivities
can be prevented with antihistamines
14-7 Checkpoint
1. Under what circumstances is an
autoimmune disorder produced?
2. In an immediate hypersensitivity, why isn’t
there an allergic reaction after the first
exposure to an antigen?