- A specific section of the brain formed by the rounded prominence on the front surface of the brainstem. (The brainstem is the lowest part of the brain that merges with the spinal cord; it consists of a structure called the medulla oblongata, the midbrain and the pons.) Cranial nerves V, VI, VII and VIII take origin at the border of the pons. Pons is Latin for bridge. It is short for the pons Varolii, the bridge of Varoli, named for a 16th-century Italian surgeon and anatomist Costanzo Varoli. The pons bridges that portion of the central nervous system between the medulla oblongata and the midbrain. The adjective for pons is pontine. Transpontine means across the bridge. In London, transpontine refers to one side of the River Thames, the south side, where the theaters playing popular melodramas were located in Victorian days. Cross a bridge over the Thames and you were in the more respectable cispontine sector of London.
* * *1. [TA] In neuroanatomy, the p. varolii or p. cerebelli; that part of the brainstem between the medulla oblongata caudally and the mesencephalon rostrally, composed of the basilar part of p. and the tegmentum of p.. On the ventral surface of the brain the basilar part of p., the white pontine protuberance, is demarcated from both the medulla oblongata and the mesencephalon by distinct transverse grooves. SYN: p. cerebelli, p. varolii. 2. Any bridgelike formation connecting two more or less disjoined parts of the same structure or organ. [L. bridge]- p. basilaris pontis [TA] SYN: basilar part of p..- p. cerebelli SYN: p. (1).- p. hepatis a bridge of liver tissue that sometimes overlaps the fossa of the inferior vena cava, converting it into a canal. SYN: ponticulus hepatis.- p. varolii SYN: p. (1).
* * *pons 'pänz n, pl pon·tes 'pän-.tēz a broad mass of chiefly transverse nerve fibers in the mammalian brain stem lying ventral to the cerebellum at the anterior end of the medulla oblongata
* * *n.2. any portion of tissue that joins two parts of an organ.
* * *(ponz) gen. ponґtis pl. ponґtes [L. â€œbridgeâ€] bridge: any slip of tissue connecting two parts of an organ. [TA] the part of the central nervous system lying between the medulla oblongata and the mesencephalon, ventral to the cerebellum; it consists of an anterior and a posterior part (see pars basilaris pontis and tegmentum pontis). See Plate 9. See also brainstem.
Pons and adjacent structures in a midline sagittal section.
Medical dictionary. 2011.