Gain a better understanding of medical terminology by searching our dictionary of more than 1,300 terms.


Filter By Alphabet
All terms
  • spleen

    The blood-forming and -storing organ located under the ribs in the upper left portion of the abdomen.

  • spirochete

    Spiral-shaped bacteria.

  • spina bifida

    A birth defect caused by imperfect closure of part of the spinal column, exposing some of the nervous system.

  • sphygmomanometer

    An instrument for measuring blood pressure. An inflatable blood-pressure cuff.

  • sphincter

    A ring-shaped muscle that surrounds a natural opening in the body and can open or close it by relaxing or…

  • sperm

    The male germ cell. Also called spermatozoon.

  • speculum

    An instrument for opening a body cavity to permit visual inspection.

  • specimen

    A sample taken to study the nature of the whole.

  • spasm

    A sudden, involuntary contraction of a muscle or group of muscles.

  • solar plexus

    The network of nerves in the center of the abdomen.

  • soft tissue

    The substance of an organic body or organ consisting of cells and intercellular materials. The muscles and other nonbony tissues…

  • soft palate

    The soft part of the roof of the mouth in the back, toward the throat.

  • snoring

    Harsh breathing sounds during sleep caused by the vibration of the soft palate during inhalation.

  • Snellen's chart

    A chart of block letters used to test distant vision.

  • sneeze

    To exhale breath from the nose and mouth in a sudden, involuntary action as a result of irritation of the…

  • smooth muscle

    A type of muscle tissue controlled by the involuntary nervous system, occurring in the walls of the uterus, intestines or…

  • smallpox

    A viral disease that was once highly contagious. Characterized by high fever, vomiting, and blisters and sores on the skin…

  • skull

    The bony framework of the head.

  • skeleton

    The hard bony framework of the human body that supports the tissues and protects the organs.

  • sitz bath

    A bath in which only the hips and buttocks are immersed in water for relief of rectal or vaginal…

  • sinusitis

    Inflammation and infection of the sinuses.