Download Human Disease Ch 2

Chapter 2
Immunity and the Lymphatic System
Immunity
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Immunity: The ability of the body to defend
itself against infectious agents, foreign cells
and even abnormal body cells.
Specific immunity: Also known as acquired
immunity, effective against particular
identified foreign agents and develops in
response to contact with that agent.
Autoimmunity: Occurs when individuals
develop antibodies to their own tissues or
self-antigens.
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Orderly Function of the Immune System
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Functional components of the immune
system:
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lymphoid tissue
• Primary – thymus, bone marrow
• secondary – tonsils, adenoids, spleen, Peyer patches,
appendix
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lymphocytes
antibodies
macrophages
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Orderly Function of the Immune System
(cont’d.)
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Major functions of the immune system:
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Protect the body against foreign organisms
Maintain homeostasis by eliminating damaged
cells (phagocytosis)
Battles infection
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Orderly Function of the Immune System
(cont’d.)
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Inappropriate responses of the immune
system:
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Hyperactive (allergic) – excessive response
Immunodeficient (e.g., AIDS) – inadequate
response
Autoimmune (e.g., SLE) – misdirected response
Transplant rejection – attack to beneficial foreign
tissues
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Immunodeficiency Diseases (cont’d.)
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Acquired Immunodeficiency Syndrome
(AIDS)
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Caused by human immunodeficiency virus (HIV)
 Diagnosed by presence of HIV antibodies in the
blood (common test: ELISA; confirmation: Western
blot)
 HIV attacks helper T lymphocytes
 Reduces cell-mediated immunity
 Attacks nervous system directly
Elsevier items and derived items © 2009 by Saunders, an imprint of Elsevier Inc.
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Immunodeficiency Diseases (cont’d.)
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HIV transmission is through direct contact with blood
or semen of infected person
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sexual contact
blood transfusions and other blood products
contaminated shared needles (IV drug use, etc.)
accidental needle sticks
to fetus via placenta or during birth process from infected
mother
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Immunodeficiency Diseases (cont’d.)
Universal Precautions
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Thorough and frequent hand washing.
Personal protective equipment worn as required by specific task (e.g.
gloves, gown, goggles, mask).
Proper disposal of all sharps in designated biohazard containers.
No needle recap prior to disposal.
Caution in handling of laboratory specimens.
Proper containment and disinfection of blood and body fluid spills.
Use clean mouthpieces and resuscitation bags.
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Autoimmune Diseases
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Lymphocytes and antibodies are sensitized to
develop against the body’s own organs or
tissues.
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May be triggered by disease, injury,
metabolic changes, or mutation in
immunologically competent cells.
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May be caused by certain drugs or
chemicals, trauma, or viral infection.
Elsevier items and derived items © 2009 by Saunders, an imprint of Elsevier Inc.
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Autoimmune Diseases (cont’d.)
Pernicious Anemia
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Symptoms: weakness and tingling and
numbness in extremities, altered vision,
lightheadedness, tinnitus, palpitations, weight
loss, digestive disturbances, sore tongue.
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Signs: decreased red blood cell, white blood
cell, and platelet counts; increased red blood
cell mean volume; decreased hemoglobin
levels; jaundice; optic nerve atrophy;
decreased amount of gastric acid.
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Autoimmune Diseases (cont’d.)
Connective Tissue Diseases
 Systemic lupus erythematosus
 Scleroderma
 Sjogren syndrome
 Rheumatoid arthritis
 Juvenile rheumatoid arthritis
 Ankylosing spondylitis
 Polymyositis
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Autoimmune Diseases (cont’d.)
Systemic Lupus Erythematosus (SLE)
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Inflammation of skin, joints, nervous system,
kidneys, lungs, and other organs.
Butterfly rash across face may be present.
Other rashes may appear on other exposed skin
areas.
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Autoimmune Diseases (cont’d.)
Systemic Lupus Erythematosus (SLE)
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Butterfly face rash
Alopecia
Photosensitivity
Raynaud’s phenomenon
Thrombocytopenia
Discoid skin lesion
Nasopharyngeal ulceration
Polyarthritis
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Pleuritis or pericarditis
Protein or casts in the
urine
Hemolytic anemia
False-positive serology
Abnormal blood
antibodies
LE cells (leukocytes)
present in lab testing
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Autoimmune Diseases (cont’d.)
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Rheumatoid arthritis (RA)
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Chronic, inflammation and edema of the synovial
membranes surrounding joints.
Destruction of cartilage and adjacent bone.
May produce weight loss, fever, and malaise.
Joint pain and stiffness, especially in morning.
Bilateral joint tenderness, edema, erythema, warmth.
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Autoimmune Diseases (cont’d.)
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Multiple sclerosis (MS)
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Inflammatory disease of the central nervous
system.
Demyelination of nerves occurs in the brain and
spinal cord.
Signs and symptoms are primarily neurologic and
related to areas of myelin destruction.
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Autoimmune Diseases (cont’d.)
Myasthenia gravis (MG)
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Chronic progressive neuromuscular disorder.
Autoantibodies produced to acetylcholine receptor
in muscle cells.
Ineffective nerve-muscle junction results in severe
weakness, difficulty talking and swallowing,
drooping eyelids and diplopia.
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Autoimmune Diseases (cont’d.)
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Vasculitis
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Inflammation in the walls of blood vessels that
may lead to necrosis, thrombus formation, and
local infarct
Can be classified as small vessel or systemic;
affecting medium and large arteries
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