ch 10 immune system pp

the body protects itself from infectious organisms through the

host defense system

three lines of defense

physical and chemical barriers to infection

inflammatory response

immune response

physical barriers

like skin and mucous membranes

prevent most organisms from invading the body

organisms that penetrate first barrier trigger the

inflammatory and immune responses

both responses involve stem cells in the bone marrow that form blood cells

structures of the immune system

bone marrow

lymph nodes

thymus

spleen

tonsils

bone marrow

b cells are produced and develop here and then migrate to the lymph nodes

lymph nodes

are distributed along lymphatic vessels throughout the body

they filter lymphatic fluid, which drains from body tissues and later returns to blood as plasma

thymus

between lungs

secretes a group of hormones that enable lymphocytes to develop into mature t cells

spleen

largest lymphatic organ

functions as a reservoir for blood

cells in the splenic tissue clear cellular debris and process hemoglobin

tonsils

consist of lymphoid tissue and also produce lymphocytes

location of tonsils allows them to guard the body against airborne and ingested pathogens

types of immunity

cell-mediated

humoral

cell-mediated immunity

t cells respond to antigen

t cells destroy target cells such as cancer or bacteria

t cells can kill cells, help stimulate b cells or even suppress cells

humoral immunity

b cells respond to antigen

b cells produce antibodies that will destroy bacteria and viruses

types of disorders

immunodeficiency disorders

hypersensitivity disorders

autoimmune disorders

immunodeficiency disorders

decreased or compromised ability to respond to antigens

hypersensitivity disorders

abnormal sensitivity to a stimulus of any kind

autoimmune disorders

body’s normal tolerance of the antigens on its own cells is disrupted

immune disorders

allergic rhinitis

anaphylaxis

human immunodeficiency virus disease HIV

lupus erythematosus

rheumatoid arthritis

allergic rhinitis

type I, IgE-mediated response to allergen

anaphylaxis

type I allergic reaction from systemic exposure to antigen

human immunodeficiency virus disease HIV

ribonucleic acid retrovirus replicates within the CD4 cell, resulting in cell death

lupus erythematosus

antibodies are produced against body’s own cells

normal immunity suppressed by formed antigen-antibody complex that results in tissue damage

rheumatoid arthritis RA

exposure to an antigen causes altered IgG antibodies to develop

the body doesn’t recognize these antibodies, and an antibody known as rheumatoid factor forms against them