The Immune System

Prepared by Mickelder Kercy, MD - Instructor

Central Lymphoid Tissue : - Bone marrow(stem

cells that differentiate into the mature lymphocytes

B + Natural Killer cells)

Anatomy of the Immune System

- Thymus(posterior to

the sternum in the anterior mediastinum. Immature

lymphoid cells enter the cortex, reproduce and mature

into T cells, then move to the medulla where they

reenter the circulation)

Peripheral Lymphatic System : - Spleen (LUQ, blood

vessels are surrounded by B and T cells that track down

the germs in the blood. Divided into a cortex and a

medulla)

- lymph nodes(The cortex

has germinal centers filled with B cells producing

specific antibodies and T lymphocytes passing through

the lymph node. The medulla has macrophages)

- Appendix, lymphatic

capillaries, lymphatic vessels and lymphatic ducts

The Immune System Responses

Antibody-mediated/Humoral Immunity

Cell-mediated Immunity

Remembers the antigen of the germ so that

more cells attack faster in the next invasion

Inhibit/control T and B cells activity

Secrete lymphokines that stimulate killer

T and B cells

Release chemicals that create holes in

the cell destroying it

Cloned into these 4 following T cells

Ingest the germ then shows its antigen to

the T cells

Macrophages (Neutrophils)

T Cells

Cytotoxic Killer T Cells

Helper T Cells

Suppressor T Cells

Memory T Cells

The Types of Immunity

Immunoglobulins/antibodies taken from the plasma of human donors (HAIG, HBIG, TIG, RIG, VZIG)

Killed germs or live germs with attenuated

toxins in vaccines (MMR, Dtap, Tetanus etc..

1st exposure to Chickenpox virus leads to

long lasting immunity

IgA from breastfeeding (6 months protection). IgG

from the placenta

Acquired

Naturally Acquired

Active

Passive

Artificially Acquired

(Lab)

Passive

Active

•Stomach acid

•Skin

•Mucus, which traps bacteria and small particles

•Enzymes in tears and skin oils

•Cough reflex

To the HIV virus and sickle-cell trait persons to the parasite

(plasmodium falciparum) causing malaria

Genetic/Inborn

Allergies : Hypersensitivity to dust, mold, pollen

Common Disorders associated with the Immune System

Anaphylaxis : Extreme allergic reaction that can be

life-threatening

Cancer : Cells in the body that divide abnormally

and grow abnormally (not well differentiated)

misusing the body’s nutrients at the expense of

healthy/normal cells

Chronic Fatigue Syndrome : Caused by a defect in

the immune system

Infectious Mononucleosis/kissing disease : Caused

by the Epstein-barr virus(EBV) leading to an increase

in the number of WBC (monocytes and lymphocytes) .

Spread by saliva.

Lymphedema : Swelling due to fluid retention in the

tissue caused by lymphatic obstruction

Before After Rx

Rheumatoid Arthritis : Inflammation of the joints.

The damage is done by the confused cells of the

immune system that are activated by antibodies that

abnormally stick to the body’s own cells

Systemic Lupus Erythematosus : Immune disorder

affecting the whole body due to abnormal antibodies

sticking to the body’s own cells misleading the cells of the

immune system to destroy the body’s own cells

The End