Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «O»:
Ossification: The process of creating bone, that is of transforming cartilage (or fibrous tissue) into bone.
The human skeleton initially consists largely of cartilage which is relatively soft and is gradually transformed into hard bone during infant and child development.
The verb corresponding to...
Ossify: To make into bone; to convert cartilage or fibrous tissue into bone.
The skeleton initially consists mainly of cartilage which is gradually transformed into bone during development. This bone-building process is termed "ossification." Bone is "osseous" tissue. "Os" is a synonym for "bone."
Osteitis: Osteitis is inflammation of the bone.
For example, patients with what is called the SAPHO syndrome develop osteitis -- the O in SAPHO stands for oteitis -- and the bone inflammation typically affects the sacroiliac joints (sacroiliitis) and the spine (spondylitis). This leads to pain and s...
Osteitis deformans: Better known today as Paget disease, this is a chronic bone disorder that typically results in enlarged, deformed bones due to excessive breakdown and formation of bone tissue that can cause bones to weaken and may result in bone pain, arthritis, bony deformities and fractures. T...
Osteitis fibrosa cystica
Osteitis fibrosa cystica: A condition associated
with hyperparathyroidism in which bone tissue is gradually
replaced by cysts and fibers....
Osteo- (prefix): Combining form meaning
bone. From the Greek "osteon", bone. Appears for instance in
osteoarthritis, osteochondroma osteodystrophy, osteogenesis,
osteomyelitis, osteopathy, osteopetrosis, osteoporosis, osteosarcoma,
Osteoarthritis: A type of
arthritis caused by inflammation, breakdown, and eventual loss of cartilage in the
joints. Also known as
Osteoarthropathy: Any disease of the bones and joints. From osteo-, bone + -arthro-, joint, + pathy, disease....
Osteoblast: A cell that makes bone. It does so by producing a matrix that then becomes mineralized. Bone mass is maintained by a balance between the activity of osteoblasts that form bone and other cells called osteoclasts that break it down. See also: Osteoclast....
Osteoblastoma: A benign tumor in bone
tissue. Osteoblastomas are small, and are seen most
frequently in children or young adults. Symptoms include
pain and bone mass reduction. Treatment is primarily by surgery. Chemotherapy and radiation have also been used to treat osteoblastoma but are controv...
Osteochondritis dissecans: A condition in which a
fragment of bone in a joint is deprived of blood and
separates from the rest of the bone, causing soreness and
making the joint "give way". Diagnosis is by X-ray.
Treatment is usually by casting, although if the fragment
has detached completely,...
Osteochondroma: An abnormal, solitary, benign growth
of bone and cartilage, typically at the end of a long bone.
Osteochondromas are usually discovered in persons 15 to 25 years of
age. They are typically detected when the area is injured, or when
they become large. It can be a hereditary condit...
Osteochondromatosis: A condition characterized by multiple benign tumors of cartilage called osteochondromas projecting from bone, most often from near the ends of long bones. In a small proportion of cases, an osteochondroma may become malignant. The propensity to develop multiple osteochondromas i...
Osteochondromatosis, synovial: A disorder of a joint featuring a change of the normal joint lining (synovium) tissue's cellular structure to form bone-cartilage tissue. Synovial osteochondromatosis is uncommon. It typically presents in young to middle-aged adults. Synovial osteochondromatosis leads ...
Osteochondrosis: Any disease that affects the
progress of bone growth by killing bone tissue.
Osteochondrosis is seen only in children and teens whose
bones are still growing....