Cox, Jessica; Lymp. Immune System

immune system

innate ( nonspecific) defense system

first line of defense ; external body membranes (skin and mucosae)

second line of defense; antimicrobial proteins, phagocytes and other cells

adaptive (specific) defense system

third line of defense; attacks particular forgin substances

acid of skin,enzymes like saliva and mucin sticky mucus that lines digestive and respiratory tracks

phagocytes are white blood cells that eat foreign invaders neurophils are the most abundant phagocytes but die fighting macrophages develop from monocytes & are chief phagocytic

Natural killer cells can kill cancer and virus infected cells , memory cells keep track of each virus that had entered your body so it can be killed faster the next time it comes back.

lymphatic system

fluid balance

Absorption

the immune system

anatomy of the lymphatic system

tonsils

located in the back of mouth/throat

produce lymphocytes and antibodies; protect against inhaled and swallowed foregin bodies

spleen

fist size located in the upper left side of abdomen

filter blood to remove microbes and old damaged red blood cells and platelets

thymus gland

found behind the sternum

secretes hormones and is crucial in the production, maturation and differentiation of immune T cells

bone marrow

where B cell lymphocytes of the immune system mature

returns excess fluid and proteins from the tissues that can not be returned through blood vessels

absorption of fatty acids and subsequent transport of fat, Chyle to the circulatory system

production of immune cells; lymphocytes, monocytes, and antibody, producing cells of plasma cells

immune defenses

innate (nonspecific) defense system

first and second lines of defense (skin,stomach acid,tears, mucosae)

second line - antimicrobial proteins,phagocytes

adaptive (specific) defense system

third line of defense attacks particular foreign substances

inhibit spread of invaders; inflammation is the most important mechanism

Pathocytes - eat forign invaders

Uses PATHOGENS :

natural killer (NK) cells - can kill cancer and virus infected cells before adaptive immune system in activated

humoral and cellular immunity

humoral immunity

cellular immunity

antibodies produced by lymphocytes, circulate freely in body fluids

bind temporally to target cell

mark for destruction

lymphocytes act against target cell

directly by killing infected cells

indirectly by releasing chemicals that enhance inflammatory response; or activating other lymphocytes or macrophages

recognizes and targets specific antigens

it is systemic; not restricted to initial site

it has memory; mounts on even stronger attack to" known " antigens

antigens & antibodies

antigens

antibodies

substances that can mobilize adaptive defenses and provide an immune response

most large complex molecules found in body (nonself) characteristics of antigens

can be a complete antigen or hapten (incomplete)

contain derminations; can be self antigen

do not destroy antigens; they inactivate them

neutralization

prevent antigens from binding to receptors on tissue cells

form antigen-antibody (immune) complexes

activate mechanisms that destroy virus

go after extracellular pathogens; they do not invade solid tissue unless legion is present

cellular immune response

T cells

provide defense against intracellular antigens

some directly kill cells, others release chemicals that regulate immune response

made in thymus; mature in bone marrow

CD4 cells usually become helper T cells that can activate B cells

CD8 cells become cytotoxic T cells

also become memory T cells

B cells

produce antibodies

humoral immunity

recognize specific non self antigens

made in thymus mature in bone marrow

disorders of immune system

autoimmune disease

results when immune system looses ability to distinguish self from foreign

autoimmunity

production of autoantibodies & sensitized Tc cells that destroy body tissues

immediate hypersensitivity ( allergies)

seconds after contact with allergen, antigen causes allergic reaction

body is overreacting to foreign antigens that are not dangerous to most people

lymphocytes ( white blood cell)

present antigens to helper T cells to assist their own activation

macrophage

B & T cell

activated macrophage becomes phagocytic killer

present antigens to T cells , which not only activates T cell, but also further activate macro phage