(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 unbranched portion of the median nerve (which arises from the cubital fossa) innervates muscles of superficial and intermediate groups of the anterior(flexor) compartment except flexor carpi ulnaris.he median nerve originates from the lateral and medial cords of the brachial plexus, and has contributions from ventral roots of C5 & C6 (lateral cord) and C8 & T1 (medial cord).