Obex: Opening in the floor of the fourth
cerebral ventricle through which spinal fluid enters the center
of the spinal canal.
Oblique X-ray: X-rays taken from an angle
that allows for a direct view through the nerve canal or foramina.
Obturator: An opening in the low pelvis.
Occipital Condyle: the joint at the base
of the skull that articulates with the upper part of the first
Occipital muscles: Muscles behind the back
of the neck that reach the back of the skull.
Occiput: The back of the skull.
Operating microscope: A type of microscope
that is used for surgery , typically spinal surgery, that
provides a 3-dimensional magnified view with superior lighting.
Opiates: Narcotic medications.
OPLL (ossification of the posterior longitudinal ligament):
An abnormal bone formation within the spinal canal, along
the dura that is anterior to the spinal cord and posterior
to the vertebrae.
Osteoblast: A type of cell that generates
Osteoclast: A type of cell that can digest
or destroy bone.
Osteoconductive: Material that helps provide
a medium for bone formation.
Osteocyte: A bone cell.
Osteogenesis: The formation of new bone.
Osteogenic proteins: Proteins that promote
the formation of new bone.
Osteoinductive: Proteins and materials that
encourage the body to produce ostegenic proteins.
Osteomyelitis: An infection of bone.
Osteophyte: A bone spur.
Osteoporosis: Softening of bone due to loss
of calcium, typically with age.