Lymphatic System &Body DefensesAnatomy and Physiology II

Mrs. Harborth

Lymphatic System

Made of: Lymphatic vessels

Lymphatic tissues and organs

Lymphatic Vessels

Pick up excess fluid (lymph) in the tissues and returns it to bloodstream

Flows only toward the heart

Vessels lead to one of 2 large ducts Right lymphatic duct

Thoracic duct

Lymph Nodes

Remove foreign material from lymphatic stream and produce lymphocytes

Most are kidney-shaped, less than an inch long

Cortex Follicles

Germinal Centers

Plasma cells

Medulla

Lymphoid Organs

Lymph nodes

Spleen

Thymus gland

Tonsils

Peyer’s patches on intestines

Body Defenses

Nonspecific vs Specific defense systems

Nonspecific Body Defenses

Mechanical barriers

Cells

Chemicals

Cells and Chemicals

Phagocytes phagocytosis animation

Natural killer cells

Inflammatory response leukocyte rolling animation

Antimicrobial chemicals Complement

Interferons interferon animation

Fever Pyrogens

Iron and zinc gathered by liver/spleen

Specific Body Defenses:Immune Response

Functional system that recognizes foreign molecules (antigens) and inactivates or destroys them

Humoral (antibody-mediated) or cellular (cell-mediated) Immunity

3 aspects of immune system: 1. Antigen specificity

2. Systemic

3. Has “memory”

Antigens

Foreign proteins, nucleic acids, large carbs, some lipids

Self-antigens

Hapten (incomplete-antigen)

Lymphocytes

Originate from hemocytoblasts in red bone marrow

B cells become immunocompetent in bone marrow

T cells become immunocompetent in the thymus

Once immunocompetent, only reacts to one distinct antigen

Genetic determinance

Macrophages

Arise from monocytes in bone marrow

Engulf foreign particles and present fragments of antigens on surfaces where T cells “read” them

Monokines

Killer macrophages

Stay in lymphoid organ

Humoral Immune Response

B Lymphocytes undergo clonal selection

Plasma cells (antibody levels peak at 10 days)

Memory cells

Active Immunity

B cells encounter antigens and produce antibodies

Naturally acquired or artificially acquired

Passive Immunity

Antibodies come from outside source (animal or human)

Fetal circulation or immune serum

Monoclonal antibodies

Antibodies

IgM, IgA, IgD, IgG, IgE

Complement fixation

Neutralization

Agglutination Precipitation

Cellular Immune Response

Antigen presentation (macrophages and T cells)

Interleukin 1

Helper T cells, Cytotoxic T cells, Suppresor T cells, Delayed hypersensitivity T cells, memory cells

Organ Transplantation/Rejection

Autografts

Isografts

Allografts

Xenografts

Allergies

Immediate hypersensitivity

Delayed hypersensitivities

Immunodeficiencies

SCID

AIDS

Autoimmune Diseases

MS

Myasthenia gravis

Grave’s disease

Juvenile diabetes mellitus

Systemic lupus erythematosus

Glomerulonephritis

Rheumatoid Arthritis