Operculum (fish) Operculum (fish) The operculum is a series of bones found in bony fish that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. The opercular series contains four bone segments known as the preoperculum, suboperculum, interoperculum and operculum. The preoperculum is a crescent-shaped structure that has a series of ridges directed posterodorsally to the organisms canal pores. The preoperculum can be located through an exposed condyle that is present immediately under its ventral margin; it also borders the operculum, suboperculum, and interoperculum posteriorly. The suboperculum is rectangular in
Cerebral peduncle cerebral peduncles results in unrefined motor skills, imbalance, and lack of proprioception. The descending upper fibers from the internal capsule continue on through the midbrain and are then seen as the fibers in the cerebral peduncles. The cortico-pontine fibers are found in the outer and inner third of the cerebral peduncle, these are the cortical input to the pontine nuclei. The cortico-bulbar and cortico-spinal fibers are found in the middle third of the cerebral peduncle. The cortico-spinal tract exits the internal capsule and is seen in the mid portion of the cerebral peduncles. Cranial nerve 3 (oculomotor nerve) appears ventrally