(disk) [L. discus, fr. Gr. diskos, a dish, quoit, discus] A flat, round, platelike structure.
articular d. A biconcave oval disk of fibrous connective tissue that separates the two joint cavities of the temporomandibular joint on each side.
d. at risk An optic disk whose function is threatened by insufficient blood flow. On funduscopic examination, the optic nerve appears small and crowded, and the cup-to-disk ratio is small. SEE: cup-to-disk ratio.
herniated d. Rupture of the soft tissue that separates two vertebral bones into the spinal canal or adjacent spinal nerve roots. Herniation of intervertebral disks can cause back pain and, occasionally, loss of neurological function in the distribution of affected nerves. SYN: herniated intervertebral disk; lumbar disk prolapse; slipped disk. SEE: herniation of nucleus pulposus for illus.
herniated intervertebral d. Herniated d.
intercalated d. A modification of the cell membrane of adjacent cardiac muscle cells, consisting of extensive folds and intercellular junctions for electrical and mechanical linkage of contiguous cells. SEE: illus.
Intercalated disk at the ends of adjacent cardiac muscle cells
intervertebral d. The fibrocartilaginous tissue between the vertebral bodies. The outer portion is the anulus fibrosus; the inner portion is the nucleus pulposus. The disk is a shock absorber, or cushion, and permits movement.
optic d. The area of the retina where the optic nerve enters. SYN: blind spot (1); optic nerve head.
Z d. A thin, dark disk that transversely bisects the I band (isotropic band) of a striated muscle fiber. The thin filaments, made primarily of actin, are attached to the Z disk; the area between the two Z disks is a sarcomere.
(dis-kek′tŏ-mē) [disk- + -ectomy] Surgical removal of a herniated intervertebral disk.
percutaneous endoscopic d. A minimally invasive technique for removing extraforaminal spinal disc fragments from the body in which an endoscope is passed through the skin and advanced toward the damaged intervertebral disc.
(dis-kog′ră-fē) [disk + -graphy] Use of a contrast medium injected into an intervertebral disk so that it can be examined radiographically
Diskography may increase the risk of disk degeneration and herniation.
(dis″lō-kā′ shŏn) [1dis- + location] The displacement of any part, esp. the temporary displacement of a bone from its normal position in a joint.
anterior hip d. A dislocation of ...