(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.
The median nerve innervates the majority of the muscles in the anterior forearm, and some intrinsic hand muscles. The Anterior Forearm. In the forearm, the median nerve directly innervates muscles in the superficial and intermediate layers: 1  Superficial layer: Pronator teres, flexor carpi radialis and palmaris longus.2  Intermediate layer: Flexor digitorm superficialis.he Anterior Forearm. In the forearm, the median nerve directly innervates muscles in the superficial and intermediate layers: 1  Superficial layer: Pronator teres, flexor carpi radialis and palmaris longus. 2  Intermediate layer: Flexor digitorm superficialis.