21.1 Immune System Flashcards
Provides resistance to disease
Functional system
2 portions: innate and adaptive
Immune system
Disease causing microorganisms like bacteria, fungi, and virus
Pathogens
Nonspecific defense system
Constitutes first and second lines of defense
Ex. Skin, mucous membranes, phagocytes, interferon chemicals, inflammation, fever
Innate defense system
Specific defense system
Third line of defense that attacks particular foreign substances
Ex. B cells, T cells, antibodies, lymphocytes
Adaptive defense system
Humoral immunity
B cells
Cellular immunity
T cells
Surface membranes (skin and mucous membranes) and their secretions
Produce protective chemicals that inhibit or destroy microorganisms
First line of defense
Acidity of skin and secretions inhibits growth
Acid
Lysozyme of saliva, enzymes in stomach
Enzymes
Sticky mucus that lines digestive and respiratory tract traps things
Mucin
Antimircrobial peptides that inhibit microbial growth
Defensins
Lipids in sebum and dermcidin in sweat are toxic to some bacteria
Other chemicals
Congenital or acquired conditions that impair function or production of immune cells or molecules
Immunodeficiency
Genetic defect with marked deficit in B and T cells
Often called “bubble boy” disease
Treatment: bone marrow transplant
Various forms
Severe combined immunodeficiency syndrome (SCID)
Cripples immune system by interfering with activity of helper T cells
Characterized by weight loss, night sweats, swollen nodes
HIV
