pyramidal decussation n.
Crossing of the bundles of the pyramidal tracts at the lower border of the medulla oblongata. Also called motor decussation.
- Pyramidal fracture
pyramidal fracture n. A fracture of the midfacial bones, especially the upper jawbone, in which the principal fracture lines meet at a point above the nasal bones, forming a triangular section that is detached from the skull. Also called LeFort II fracture.
- Pyramidal muscle
pyramidal muscle n. A muscle with origin from the crest of the pubis, with insertion into the lower portion of the linea alba, with nerve supply from the last thoracic nerve, and whose action makes the linea alba tense.
- Pyramidal orchid
noun 1. a chalk-loving orchid, Anacamptis pyramidalis, bearing a dense cone-shaped spike of purplish-pink flowers with a long curved spur
- Pyramidal muscle of auricle
pyramidal muscle of auricle n. An occasional prolongation of the fibers of the muscle of the tragus to the spine of the helix.