Medical terms A–Z

A cord-like structure in the male reproductive system that contains nerves, blood and lymph vessels, and the vas deferens (a coiled tube that carries sperm out of the testicle).

A number describing how much more ultraviolet skin can take before burning, measured under laboratory conditions almost nobody reproduces.

Its position deep within the skull places the sphenoid sinus in close proximity to structures such as the pituitary gland and nearby nerves.

A ring of muscle whose resting state is closed, opening only when the body signals that something should pass.

A lump of tissue with spikes or points on the surface.

A temporary loss of feeling in the abdomen and/or the lower part of the body.

A temporary loss of feeling in the abdomen and/or the lower part of the body.

The bones, muscles, tendons, and other tissues that reach from the base of the skull to the tailbone.

A cable of nervous tissue about as thick as a finger, and considerably shorter than the bony canal that houses it.

Timing matters more than the size of the squeeze, since what a person can still do when treatment starts largely predicts what remains.

A spinal tap withdraws cerebrospinal fluid from the lower back using a thin needle, either to test the fluid or to deliver medication.

A type of cancer that begins in the skin or in tissues that line or cover internal organs and that contains long spindle-shaped cells.

A description of shape rather than a single disease, since many unrelated cancers look this way and shape alone cannot separate them.

The bones, muscles, tendons, and other tissues that reach from the base of the skull to the tailbone.

Spine cancer describes tumors of the vertebrae or spinal cord, though cancer reaching the spine from elsewhere is far more common than a primary tumor.

A detailed picture of areas inside the body.

A fist-sized filter tucked under the left ribs, sorting worn-out blood cells from good ones and screening blood for infection.

A splenectomy is a surgical procedure that removes all or part of the spleen, performed for injury, disease, or certain blood disorders.

Having to do with the spleen (an organ in the abdomen that makes immune cells, filters the blood, stores blood cells, and destroys old blood cells).

Splenomegaly is enlargement of the spleen beyond its expected size.