Canal

or Canal is (kan-al', or kan-a' -lis). I. A tube or duct for carrying the fluids of the body. 2. A hollow instrument used as a splint. C, Abdominal. See C., Inguinal. C, Abital. See C., Aphodal. C, Aerial. See C., Air. C, Afferent. See C, Incurrent. C, Air, a cavity containing air, such as exists in most vegetable organs; it is formed by an arrest of development or by a destruction of some of the anatomic elements.. C, Alcock's, a strong sheath of the obturator layer of the pelvic fascia containing the internal pudic artery. C, Alimentary, the whole digestive tube from the mouth to the anus. C., Ali sphenoid, in comparative anatomy, a canal in the ali sphenoid bone, opening anteriorly into the foramen rotundum, and transmitting the external carotid artery. C, Alveolar, Anterior, one located in the superior maxilla; it transmits the anterior superior dental nerve. C, Alveolar, Inferior, the inferior dental canal. C, Alveolar. Median, one located in the superior maxilla and transmitting the middle superior dental nerve. C, Alveolar, Posterior, one situated in the superior maxilla; it transmits the posterior superior dental nerve. C, Alveolo-dental, See C, Dental. C, Ambulacral, in the Echinoderm at a, branches of the circular canal. C, Anal, leads from the rectum to the external opening of the anus. C, Aphodal, in certain sponges, one connecting a chamber with an excurrent canal. C, Apical, in the Ctenophora, two canals extending from the funnel to the apical pores. C, Aquiferous. 1. Canals that in many molluscs traverse the substance of the foot, opening externally by pores, or internally into the blood-sinuses. 2. In the Entozoa, a series of ramifying excretory canals, with blind extremities, converging to a common canal that opens externally. C, Arachnoid, a space formed beneath the arachnoid membrane of the brain; it transmits the vena; magna; Galeni. C. of Arantius, the duct us venosus. C, Arch i nephric, the duct of the arch i nephron or primitive kidney. C, Arterial. See Ductus arteriosus. C, Atrial, the cavity of the atrium. C, Auditory, External, that from the auricle to the tympanic membrane. C, Auditory, Internal, that beginning on the posterior surface of the petrous bone, and extending outward and backward for a distance of about four lines; it transmits the auditory and facial nerves, and the auditory artery. C, Auricular. 1. See C., Auditory, External. 2.