Health and Disease chapter 2

Immunity

Ability of the body to resist disease

Antigen

Any foreign substance that, when introduced into the body, is recognized as “nonself” and activates the immune system

Nonspecific immunity

Immunity that is present at birth and provides immediate, short-term protection against any antigen. Always prepared to defend the body against disease

Specific immunity

Immunity that responds to the presence of specific antigens and develops in response to contact with those antigens. Must be primed by an initial exposure before it can protect the body against that antigen

Pathogens

Disease-causing microorganisms

Nonspecific immunity

Physical barriers such as intact skin and mucous membranes as well as cellular and chemical defenses

Phagocytosis

Process of a cell(Leukocytes-white blood cells) engulfing and destroying foreign material

Phagocyte

Leukocyte that engulfs and destroys foreign material

Macrophanges

Found in all tissue

Neutrophils

Circulate in bloodstream

Phagocytes

attracted to areas of inflammation and activated complement

Specific immunity

Humoral immunity and cell-mediated immunity

Humoral immunity

Immune response provided by development of antibodies that counteract foreign antigens. B-cells

Cell-mediated immunity

Phagocytes and T-cells provide defense against abnormal cells, transplanted tissues and organs, and intracellular pathogens; immunity provided by special cells

B cells

Lymphocyte that provides humoral immunity. Involved in antibody secretion to target extracellular pathogens like bacteria. It originates and develops in red bone marrow and participates in memory cell formation

T cells

Lymphocyte that provides cell-mediated immunity. No antibody secretion. It targets intercellular pathogens like viruses and cancer. It originates in red bone marrow but develops in the thymus. It participates in memory cell formation

Activated B cell

divides and develops into plasma cells and long-lived memory B cells

Secondary response

quicker, produces more antibodies, and lasts longer

Helper T cell

Cells that stimulate antibody production by plasma cells, increase phagocytosis, and stimulate cytotoxic T cells and natural killer cells. Also called CD4

Activated helper T cell

divides producing T cell clones and memory T cells

Cytotoxic T cells

Cells that can recognize and eliminate infected and abnormal cells

Autoimmunity

Development of antibodies, called autoantibodies, to ones’s own tissues or self-antigens. Has no known cause and can’t be prevented

Lupus

Chronic autoimmune disease that can affect various parts of the body, including the skin, joints, heart, lungs, blood, kidneys, and brain. Mostly affects women, and it is idiopathic; however, environmental factors may trigger the disease (especially sunlight)

Lupus

Four types: systemic, cutaneous, drug-induced, and neonatal

Symptoms of Lupus

Butterfly rash, Raynard’s phenomenon, ulcers, arthritis, and photosensitivity. SLE and cutaneous don’t go away, but drug-induced and neonatal do when the environment is changed

Types of autoimmune diseases

Lupus, scleroderma, and sjogren’s syndrome

Allergy

Extreme immune response to an antigen. Can be diagnosed through skin tests. Can be treated with medicines, but prevention is preferable

Hypersensitivity

Extreme immune response to an antigen. Immediate(type I), cytotoxic(type II), immune-complex(type III), and delayed(type IV)

Type I hypersensitivity

local allergy, IgE, and anaphylaxis (helper T mediated). Epi pens to help treat a severe reaction. Examples: hay fever/hives

Type IV hypersensitivity

delayed. The allergy is due to the action of T cells, which require time to recognize the allergen and bring about allergy symptoms. Examples: poison ivy/oak and dermatitis w/ latex

Acquired immunodeficiency syndrome (AIDS)

a deadly disease caused by HIV that destroys an individual’s immune system (A reduction in the number of helper T cells—to less than 200), making the victim remarkably susceptible to infection

Human immunodeficiency virus (HIV)

Causative agent of AIDS; a retrovirus—that is, it carries its genetic information as RNA rather than DNA. Diagnosed using ELISA. 4 stages

HIV treatment

ART (antiretroviral therapy) to slow the progression of the disease