Medical terms - Letter O (page 7) | MedicalVocabulary.org

Osteoclast

A cell that nibbles at and breaks down bone and is responsible for bone resorption. Osteoclasts are large multinucleate cells (cells with more than one nucleus) that differentiate from another type of cell called a…
Osteoclastoma

A type of bone tumor characterized by massive destruction of bone near the end (epiphysis) of a long bone. The site most commonly struck by this tumor is the knee -- the far end of the femur and the near end of the…
Osteocyte

A bone cell
Osteodystrophy

Osteodystrophy: A bone disorder that adversely affects bone growth. See also renal osteodystrophy.
Osteodystrophy, renal

A bone growth disorder caused by chronic kidney failure (renal disease). Also known as renal osteodystrophy
Osteogenesis

The production of bone
Osteogenesis imperfecta

Brittle bone disease. Osteogenesis imperfecta (OI) is not one but a group of genetic diseases, all of which affect collagen in connective tissue in the body and all of which result in fragile bones. The best known types…
Osteogenesis imperfecta congenita

See: Osteogenesis imperfecta type II.
Osteogenesis imperfecta tarda

See: Osteogenesis imperfecta type I.
Osteogenesis imperfecta type 1

An inherited connective tissue disorder featuring bone fragility and blue sclerae (blue whites of the eyes). This is the classic form of 'brittle bone disease.' Osteogenesis imperfecta type 1 is an autosomal dominant…
Osteogenesis imperfecta type 2

An inherited connective tissue disorder with extremely severe bone fragility. This is the lethal form of 'brittle bone disease.' Osteogenesis imperfecta type 2 is a recessive trait with males and females affected. Two…
Osteogenesis imperfecta with blue sclerae

See: Osteogenesis imperfecta type I.
Osteogenesis, electrically stimulated

Bone growth caused by implanting electrodes in an area of bone and sending electrical current to them. This procedure may be used to jump-start the healing process when a bone has been broken
Osteoid osteoma

A benign tumor of bone tissue. It emerges most often in the teens or 20s, and is found most frequently in the femur and in males. Symptoms include pain, mostly at night. Diagnosis is by X-ray. Most cases do not require…
Osteology

The study of bones. The branch of anatomy or physical anthropology that deals with bones. Bone-ology
Osteolytic

Pertaining to the dissolution of bone, especially the loss of calcium from bone. 'Punched-out' osteolytic lesions are characteristic of metastatic lung and breast cancer and multiple myeloma
Osteolytic lesion

A 'punched-out' area of severe bone loss. Osteolytic lesions are seen in metastatic lung and breast cancer and multiple myeloma and may cause bone pain, pathologic fractures (bones broken by disease), and hypercalcemia…
Osteomalacia

Softening of bone, particularly in the sense of bone weakened by demineralization (the loss of mineral) and most notably by the depletion of calcium from bone. Osteomalacia may be caused by poor dietary intake or poor…
Osteomyelitis

Inflammation of the bone due to infection, for example by the bacteria salmonella or staphylococcus. Osteomyelitis is sometimes a complication of surgery or injury, although infection can also reach bone tissue through…
Osteonecrosis

Bone death resulting from poor blood supply to an area of bone. Also known as aseptic necrosis or avascular necrosis
Osteopath

An osteopathic physician who is a Doctor of Osteopathy (D.O.). In most US states, osteopaths must complete a course of study equivalent to that of an MD and are licensed to practice medicine. They may prescribe…
Osteopathy

A system of therapy founded in the 19th century based on the concept that the body can formulate its own remedies against diseases when the body is in a normal structural relationship, has a normal environment and…
Osteopenia

Mild thinning of the bone mass, but not as severe as osteoporosis. Osteopenia results when the formation of bone (osteoid synthesis) is not enough to offset normal bone loss (bone lysis). Osteopenia is generally…
Osteopetrosis

Thickening of the bones which become abnormally dense due an inherited defect in bone resorption -- the process in which old bone is broken down and removed so that new bone can be added to the skeleton. Osteoclasts are…
Osteoporosis

Osteoporosis: Thinning of the bones with reduction in bone mass due to depletion of calcium and bone protein. Osteoporosis predisposes a person to fractures, which are often slow to heal and heal poorly. It is more…
Osteosarcoma

A cancer of the bone that occurs predominantly in adolescents and young adults. It accounts for 5 percent of cancer in children. The site of the osteosarcoma is the most important prognostic factor since it determines…
Osteosynthesis

A surgical procedure that stabilizes and joins the ends of fractured (broken) bones by mechanical devices such as metal plates, pins, rods, wires or screws. Osteosynthesis refers particularly to internal fixation of a…
Osteotomy

Taking out part or all of a bone, or cutting into or through bone.
Osteotomy, block

Surgical removal a section of bone
Osteotomy, cuneiform

Surgical removal of a triangular piece of bone
Osteotomy, displacement

Surgical reconfiguration of a bone by changing its physical relationship to other bones
Ostomy

An operation to create an opening from an area inside the body to the outside
Oswald Theodore Avery

See: Avery, Oswald Theodore
Ot-

Prefix meaning ear, used before a vowel, as in otalgia and otitis. Before a consonant, ot- becomes oto-, as in otolaryngologist and otoscope. From the Greek 'otos' pertaining to the ear
Otalgia

Ear pain; earache. Otalgia can originate within the ear, the ear canal, or the external ear. From otos, the ear + the Greek algos, pain
OTC (over-the-counter)

Available without a prescription. OTC drugs are available without a prescription, simply 'over the counter.' OTC drugs are in contrast to prescription drugs that require a doctor's order.
Othello psychosis

See: Othello syndrome
Othello syndrome

The delusion of infidelity of a spouse or partner. The Othello syndrome affects males and, less often, females. It is characterized by recurrent accusations of infidelity, searches for evidence, repeated interrogation…
Otic barotrauma

Middle ear problems due to changing atmospheric pressures, as when a plane descends to land. The problems include ear pain, ringing, diminished hearing and, sometimes, dizziness. Also known as aerotitis: aerotitis…
Otitis

Inflammation of the ear. Depending upon which part of the ear is inflammed, there is otitis externa, otitis media, and otitis interna
Otitis externa

Otitis externa: Infection of the skin covering the outer ear canal that leads in to the ear drum, usually due to bacteria such as streptococcus, staphylococcus, or pseudomonas. Swimmer's ear is usually caused by…
Otitis interna

Inflammation of the inner ear. Sometimes used as a synonym for labyrinthitis, inflammation of the labyrinth which is situated within the inner ear
Otitis media

Otitis media: Inflammation of the middle ear characterized by the accumulation of fluid in the middle ear, bulging of the eardrum, pain in the ear and, if eardrum is perforated, drainage of purulent material (pus) into…
Otitis media, acute

See: Acute otitis media
Oto-

An otoacoustic emission test (OAE) measures an acoustic response that is produced by the inner ear (cochlea), which in essence bounces back out of the ear in response to a sound stimulus. The test is performed by…
Otoacoustic emission test

A physician specialized in diagnosing and treating diseases of the head and neck, especially those involving the ears, nose, and throat (ENT). Also called an ENT, ENT doctor, or ENT physician.
Otolaryngologist

A physician specialized in diagnosing and treating diseases of the head and neck, especially those involving the ears, nose, and throat (ENT). Also called an ENT, ENT doctor, or ENT physician
Otolaryngology

A medical and surgical specialty concerned with the diagnosis, management, and treatment of diseases and disorders of the ear, nose, throat (ENT) and related structures of the head and neck, including the sinuses…
Otology

The study and medical care of the ear
Otopharyngeal tube

The tube that runs from the middle ear to the pharynx, known also as the Eustachian tube. The function of this tube is to protect, aerate and drain the middle ear (and mastoid). Occlusion of the Eustachian tube leads to…