Body systems

Sinoatrial node: a small cluster of cells in the right atrium that starts each heartbeat.

Having to do with the sacrum, the triangle-shaped bone at the base of the spine between the hip bones.

The large, triangle-shaped bone at the base of the spine, between the two hip bones.

A vertical plane that divides the body or an organ into right and left parts.

The clear, watery fluid made by glands in the mouth that keeps it moist and begins digestion.

Relating to saliva, the watery fluid in the mouth, or to the glands that make it.

A gland that makes saliva and releases it into the mouth.

Either of the two main superficial veins of the leg; the great saphenous runs up the inner leg and thigh to the femoral vein in the groin.

A cancer that starts in bone or in the body's soft tissues, such as muscle, fat or blood vessels.

Severe acute respiratory syndrome: a lung infection caused by a coronavirus, first seen in 2002–2003.

A type of fat that is usually solid at room temperature, found mostly in animal foods and some tropical oils.

How full something is; in nursing, usually the percentage of hemoglobin in the blood that is carrying oxygen.

An abbreviation that most often means systolic blood pressure, and sometimes spontaneous bacterial peritonitis.

A dry, hard crust of dried blood and fluid that forms over a healing wound.

A skin infestation by tiny mites that burrow into the top layer of the skin.

The skin and tissue that cover the top of the head, where the hair grows.

The flat, triangle-shaped bone at the back of each shoulder; the shoulder blade.

Tough, fibrous tissue that replaces normal skin or tissue after an injury has healed.

An infection with group A strep bacteria in which a toxin made by the bacteria causes a red rash over the body.

A long-term mental illness that changes a person's thinking, feelings and behavior, often with a loss of contact with reality.

A cell that wraps a stretch of an axon in the peripheral nervous system with myelin.

The largest nerve in the body, which runs from the lower spine through the buttock and down the back of the thigh to serve the leg and foot.

Severe combined immunodeficiency: a group of rare inherited disorders in which the immune system barely works from birth.

The tough white outer layer of the eyeball.

Abnormal hardening of a body tissue, often from scarring.

A sideways curve of the spine.

The pouch of skin and muscle that holds the testicles.

A small gland in the skin that releases an oil (sebum) into the hair follicles to keep skin and hair soft.

A common, long-lasting inflammation of the skin in oily areas such as the scalp, face and chest.

A hormone from the lining of the duodenum, released when acid chyme arrives, that makes the pancreas send out juice rich in bicarbonate.

A substance a gland or cell makes and releases, such as mucus, saliva, sweat or a hormone.

A sudden burst of abnormal electrical activity in the brain that changes movement, feeling, behavior or awareness.

The picture a person has of who they are, including their abilities, roles, body and worth.

How much a person values and respects themselves.

Hurting one's own body on purpose, such as by cutting, burning or hitting oneself.

The saddle-shaped hollow on top of the sphenoid bone, in the floor of the skull, that holds the pituitary gland.

The thick, whitish fluid released from the penis in ejaculation, made of sperm and the secretions of the male glands.

The three fluid-filled loops of the inner ear, set at right angles to one another, that sense the head turning.

One of a pair of glands behind the bladder that make most of the fluid in semen, rich in the sugar fructose.

The tightly coiled tubes inside each testis where sperm are made.

The ability to feel touch, pain, temperature, position or other input through the senses, or a feeling itself.

Hearing loss from a problem in the cochlea, the hearing nerve or the brain's hearing pathway.

Relating to the senses, or to the nerves that carry feeling from the body to the brain.

A loss or weakening of one or more senses, such as sight, hearing, touch, taste or smell.

A nerve that carries signals about touch, pain, temperature, position and the other senses toward the brain and spinal cord.

Fear and distress that a young child shows when separated from a parent or main caregiver.

A severe whole-body response to an infection that damages the body's own organs.

The most severe stage of sepsis, in which the circulation fails and blood pressure stays low even after IV fluids.

A wall of tissue that divides two spaces or cavities, such as the two sides of the heart or nose.

A serous membrane; in the digestive tube, the outermost layer of the wall, made of visceral peritoneum over loose connective tissue.