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Glossary

Showing 851-860 out of 1154 Terms

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  • Operating room

    Surgical site.

  • Ophthalmologist

    OF-thul-MAH-loh-jist

    A doctor who has special training in diagnosing and treating eye problems, including injury and disease.

  • Opioid

    (OH-pee-OYD)

    A substance used to treat moderate to severe pain. Opioids are like opiates, such as morphine and codeine, but are not made from opium. Opioids bind to opioid receptors in the central nervous system. Opioids used to be called narcotics. An opioid is a type of alkaloid.

  • Optic nerve

    (OP-tik nerv)

    The nerve that carries messages from the retina to the brain.

  • Optical

    Pertaining to the sense of sight or to the eyes.

  • Organ

    (OR-gun)

    A part of the body that performs a specific function. For example, the heart is an organ. organelle.

  • Organism

    (OR-guh-NIH-zum)

    A living thing, such as an animal, a plant, a bacterium, or a fungus.

  • Orgasm

    (OR-ga-zum)

    The final part of the sex act, which involves contraction of sexual organs and a sudden release of endorphins, leading to a feeling of pleasure. In males, orgasm usually occurs with release of semen.

  • Orthopedic surgeon

    (OR-thuh-PEE-dik SER-jun)

    A surgeon who has special training in diagnosing and treating injuries and diseases of the musculoskeletal system. This includes the bones, joints, tendons, ligaments, and muscles.

  • Osteomyelitis

    Inflammation of the bone caused by an infection, which may spread to the bone marrow and tissues near the bone. Osteomyelitis can cause severe pain in the infected bone. If it is not treated, it can kill bone tissue.