Acquired immunodeficiency syndrome (AIDS

Disease caused by human immunodeficiency virus (HIV); involves break down of the immune system

Antibodies

Protein molecules that attach to the surface of specific antigens in an effort to destroy them

Antigens

Foreign substances such as bacteria, fungi, protozoa, and viruses that cause the immune system to react

Assistive devices

Devices that allow a person with a disability to communicate, see, hear, or maneuver. Examples include wheelchairs, motorized scooters, hearing aids, and telephone communications devices (TTD/TTY)

Atria (atrium)

two upper, thin-walled chambers of the heart

Autoimmune disease

Diseases that occur when the immune system wrongly attacks systems that it should be protecting

Axon

A conduction fiber that conducts impulses away from the body of a nerve cell

Blood pressure

of the pressure of the blood against the wall of a blood vessel

Brain injury (BI)

Damage to the brain arising from head trauma (falls, automobile accidents), infections (encephalitis), insufficient oxygen (stroke), or poisoning

Cardiovascular system

Biological system made up of the heart and the blood circulatory system

Diabetes mellitus

A disease of the endocrine system resulting from insulin deficiency or resistance to insulin’s effects

Endocrine system

A body system that is involved in growth, metabolism, development, learning, and memory. Made up of glands that secrete hormones into the blood system

Feedback control mechanism

The mechanism by which the body controls the secretion of hormones and therefore their actions on target tissues

High blood pressure (hypertension)

Blood pressure greater than 140/90; the leading cause of strokes and a major risk factor for heart attacks and kidney failure

Human immunodeficiency virus (HIV)

The virus that causes acquired immunodeficiency syndrome (AIDS)

Immune system

Organs and cells that interact and work together to defend the body against disease

Lymphocytes

White blood cells

Musculoskeletal system

Muscles that are attached to bone and cross a joint. Their contraction and relaxation are the basis for voluntary movements

Nervous system

The biological system responsible for processing and integrating incoming sensory information; it influences and directs reactions to that information

Neuron

Nerve cell that is the basic working unit of the nervous system. Composed of a cell body, dendrites (receptive extensions), and an axon

Neurotransmitters

Messenger molecules that transfer chemical and electrical messages from one neuron to another

Nonspecific immunity

Immunity that includes physical barriers to infection, inflammation, and phagocytosis. Does not include antibodies or cell-mediated immunity

Postpoliomyelitis syndrome (PPS)

Progressive atrophy of muscles in those who once had

Polio

Specific immunity

Immunity that involves cells (lymphocytes) that not only respond

to an infection but develop a memory of that infection and allow the body to defend against it rapidly in subsequent exposure

Synapse

A gap between an axon and dendrite. The site at which chemical and electrical

communication occurs

Testes

Male gonads, best known for their functions in producing sperm (mature germ cells that fertilize the female egg) and in secreting male hormones called androgens

Uterus

Also called the womb, serves as the pear-shaped home for the unborn child for the nine months between implantation and birth

Ventricles

The two lower, thick-walled chambers of the heart