(Botany) an association of a fungus and a plant in which the fungus lives within or on the outside of the plant's roots forming a symbiotic or parasitic relationship. See ectotrophic mycorrhiza, endotrophic mycorrhiza. [C19: from myco- + Greek rhiza root]
Medical Definition of POSTERIOR MEDIAN SULCUS. : a shallow groove along the midline of the posterior part of the spinal cord that separates the two posterior funiculi and is the external boundary of the posterior median septum. a shallow groove along the midline of the posterior part of the spinal cord that separates the two posterior funiculi and is the external boundary of the posterior median septum.
Tibialis posterior â¢ Origin: posterior surface of the upper half of the adjacent surface of tibia & fibulaâ¢ Insertion: navicular, cuneiforms, and cuboid bones and bases of the 2nd-5th metatarsal bones.â¢ Note: passes posterior to medial malleolus.â¢ Actions: â plantar flexion â inversion of the foot Posterior.