Body systems

Gamma-aminobutyric acid: the brain's main calming (inhibitory) neurotransmitter.

The way a person walks.

The tough, flat sheet of tendon over the top of the skull that joins the front and back bellies of the occipitofrontalis muscle; a layer of the scalp.

A small pear-shaped sac under the liver that stores bile and releases it to help digest fat.

A hard, pebble-like lump that forms in the gallbladder from substances in bile.

A cluster of nerve cell bodies outside the brain and spinal cord; plural ganglia.

The death of body tissue because its blood supply has been lost or because of severe infection.

The movement of oxygen from the air sacs of the lungs into the blood and of carbon dioxide from the blood into the air sacs.

Relating to the stomach.

The digestive fluid made by the glands of the stomach lining: water, mucus, hydrochloric acid, pepsinogen, intrinsic factor and gastric lipase.

A hormone made by G cells in the stomach lining, mostly in the pyloric antrum, that raises the stomach's acid secretion and speeds its emptying.

Inflammation of the lining of the stomach.

The large, two-headed muscle that forms the bulge of the calf and points the foot down.

Inflammation of the stomach and intestines.

The backward flow of stomach contents up into the esophagus.

A long-term condition in which stomach contents, including acid, flow back up into the esophagus.

Having to do with the stomach and intestines, or with the whole digestive tract from the mouth to the anus.

The long tube that food passes through, from the mouth to the anus.

An anxiety disorder in which a person feels excessive, hard-to-control worry about many everyday things for at least six months.

Relating to the sex organs, especially the outer ones.

A small, soft growth on or around the genitals or anus caused by certain types of human papillomavirus (HPV).

The reproductive organs, especially the external sex organs.

Relating to the genital (reproductive) organs and the urinary organs together.

Relating to older adults and their health care.

The renal fascia: the outer layer of connective tissue that encloses each kidney, its surrounding fat and the adrenal gland, and anchors them in place.

The time a baby develops in the uterus, from conception to birth; pregnancy.

High blood sugar that first develops during pregnancy in a person who did not have diabetes before.

High blood pressure that starts after 20 weeks of pregnancy in a person whose blood pressure was normal before.

Abnormally great growth and height in a child, caused by too much growth hormone before the bones stop growing.

The gums: the firm pink tissue that covers the jawbone and surrounds the base of the teeth.

Inflammation of the gums.

An organ or group of cells that makes and releases a substance the body uses, such as a hormone, sweat or saliva.

The rounded tip of the penis, formed by the end of the corpus spongiosum, where the external urethral meatus opens.

A scoring tool that rates a person's level of consciousness by their eye opening, verbal response and movement, from 3 to 15.

An eye disease in which the optic nerve is damaged, usually with raised pressure inside the eye, leading to loss of vision.

Relating to the glomerulus, the tiny cluster of capillaries in each nephron of the kidney that filters the blood.

The first step in making urine, when the kidneys' tiny filters let water and small substances pass out of the blood.

How much blood the kidneys filter each minute, used as the main measure of kidney function.

Inflammation of the glomeruli, the tiny filtering units of the kidneys.

A tiny ball of capillaries in the kidney that filters the blood as the first step in making urine.

The sound-making part of the larynx: the true vocal cords and the opening between them.

The making of new glucose by the body from substances that are not carbohydrates, such as protein and fat.

A simple sugar that is the body's main source of energy.

The main chemical messenger in the brain that excites nerve cells, making them more likely to fire.

The stored form of glucose, kept mainly in the liver and muscles.

The first stage of breaking down glucose inside a cell to release energy.

An enlarged thyroid gland, seen or felt as a swelling at the front of the neck.

An organelle made of stacks of flat membrane sacs that sorts, changes and packages the cell's products and sends them where they go.

A sex gland: an ovary or a testis, which makes eggs or sperm and sex hormones.

A hormone that acts on the ovaries or testes: FSH and LH from the anterior pituitary, and human chorionic gonadotropin (hCG) from the placenta.