optic canal

canal /ca·nal/ (kah-nal´) a relatively narrow tubular passage or channel.

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adductor canal  a fascial tunnel in the middle third of the medial part of the thigh, containing the femoral vessels and saphenous nerve.

Alcock's canal  pudendal c.

alimentary canal  the musculomembranous digestive tube extending from the mouth to the anus.

anal canal  the terminal portion of the alimentary canal, from the rectum to the anus.

Arnold's canal  a channel in the petrous portion of the temporal bone for passage of the vagus nerve.

atrioventricular canal  the common canal connecting the primordial atrium and ventricle; it sometimes persists as a congenital anomaly.

birth canal  the canal through which the fetus passes in birth.

caroticotympanic canals  tiny passages in the temporal bone connecting the carotid canal and the tympanic cavity, carrying communicating twigs between the internal carotid and tympanic plexuses.

carotid canal  a tunnel in the petrous portion of the temporal bone that transmits the internal carotid artery to the cranial cavity.

cochlear canal  see under duct.

condylar canal , condyloid canal an occasional opening in the condylar fossa for transmission of the transverse sinus.

canal of Cuvier  ductus venosus.

Dorello's canal  an occasional opening in the temporal bone through which the abducens nerve and inferior petrosal sinus enter the cavernous sinus.

facial canal  a canal for the facial nerve in the petrous portion of the temporal bone.

femoral canal  the medial part of the femoral sheath lateral to the base of the lacunar ligament.

Gartner's canal  a closed rudimentary duct, lying parallel to the uterine tube, into which the transverse ducts of the epoöphoron open; it is the remains of the part of the mesonephros that participates in formation of the reproductive organs.

genital canal  any canal for the passage of ova or for copulatory use.

haversian canal  any of the anastomosing channels of the haversian system in compact bone, containing blood and lymph vessels and nerves.

Huguier's canal  a small canal opening into the facial canal just before its termination, transmitting the chorda tympani nerve.

Huschke's canal  a canal formed by the tubercles of the tympanic ring, usually disappearing during childhood.

hyaloid canal  a passage running from in front of the optic disk to the lens of the eye; in the fetus, it transmits the hyaloid artery.

hypoglossal canal  an opening in the occipital bone, transmitting the hypoglossal nerve and a branch of the posterior meningeal artery.

incisive canals  the small canals opening into the incisive fossa of the hard palate, transmitting the nasopalatine nerves.

infraorbital canal  a small canal running obliquely through the floor of the orbit, transmitting the infraorbital vessels and nerve.

inguinal canal  the oblique passage in the lower anterior abdominal wall, through which passes the round ligament of the uterus in the female, and the spermatic cord in the male.

interdental canals  channels in the alveolar process of the mandible between the roots of the central and lateral incisors, for passage of anastomosing blood vessels between the sublingual and inferior dental arteries.

interfacial canals  a labyrinthine system of expanded intercellular spaces between desmosomes.

medullary canal 

1. vertebral c.

2. see under cavity.

nasal canal , nasolacrimal canal a canal formed by the maxilla laterally and the lacrimal bone and inferior nasal concha medially, transmitting the nasolacrimal duct.

neurenteric canal  a temporary communication in the embryo between the posterior part of the neural tube and the archenteron.

canal of Nuck  a pouch of peritoneum extending into the inguinal canal, accompanying the round ligament, in the female; usually obliterated after birth.

nutrient canal  haversian c.

optic canal  one of the paired openings in the sphenoid bone that transmits an optic nerve and its associated ophthalmic artery.

Petit's canal  zonular spaces.

perivascular canal  a lymph space about a blood vessel.

portal canal  a space within the capsule of Glisson and liver substance, containing branches of the portal vein, of the hepatic artery, and of the hepatic duct.

pterygoid canal  a canal in the sphenoid bone transmitting the pterygoid vessels and nerves.

pterygopalatine canal  a passage in the sphenoid and palatine bones for the greater palatine vessels and nerve.

pudendal canal  a tunnel formed by a splitting of the obturator fascia, which encloses the pudendal vessels and nerve.

pyloric canal  the short narrow part of the stomach extending from the gastroduodenal junction to the pyloric antrum.

root canal  that part of the pulp cavity extending from the pulp chamber to the apical foramen.

sacculocochlear canal  the canal connecting the saccule and cochlea.

sacral canal  the continuation of the vertebral canal through the sacrum.

semicircular canals  three long canals (anterior, lateral, and posterior) of the bony labyrinth, important in the sense of equilibrium.

Semicircular canals (canales semicirculares ossei).

spermatic canal  the inguinal canal in the male.

spiral canal of cochlea  cochlear duct.

spiral canal of modiolus  a canal following the course of the bony spiral lamina of the cochlea and containing the spiral ganglion.

tarsal canal  see under sinus.

tympanic canal of cochlea  scala tympani.

uterine canal  the cavity of the uterus.

vertebral canal  the canal formed by the series of vertebral foramina together, enclosing the spinal cord and meninges.

Volkmann's canals  canals communicating with the haversian canals, for passage of blood vessels through bone.

canal of Wirsung  pancreatic duct.

zygomaticotemporal canal  see under foramen.

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optic canal

n.

The short canal through the lesser wing of the sphenoid bone at the apex of the eye socket through which the optic nerve and the ophthalmic artery pass. Also called optic foramen.

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canal

a relatively narrow tubular passage or channel.

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accessory canal

see lateral canal (below).

alar canal

in the body of the basisphenoid bone, transmits the maxillary artery.

alimentary canal

the digestive tube from mouth to anus. See also alimentary canal.

anal canal

the terminal portion of the alimentary canal, from the rectum to the anus.

atrioventricular canal

the common canal connecting the primitive atrium and ventricle; it sometimes persists as a congenital anomaly.

birth canal

the canal through which the fetus passes in birth.

carotid canal

one in the pars petrosa of the temporal bone, transmitting the internal carotid artery to the cranial cavity.

carpal canal

on the palmar surface of the equine carpus where the carpal groove is converted into a canal by the flexor retinaculum which stretches from the accessory carpal bone to the medial side of the carpus. It houses the flexor tendons.

central brain canal

lumen of the neural tube of the embryo within the brain.

cervical canal

the part of the uterine cavity lying within the cervix.

condyloid canal

in the occipital bone; transmits a vein.

canal of Corti

a space between the outer and inner rods of Corti.

external ear canal

the canal from the external auditory meatus to the eardrum.

facial canal

osseous tube in the temporal bone that transmits the facial nerve.

femoral canal

in the groin on the medial aspect of the thigh; contains the femoral artery and vein.

c's of Gartner

in the ventral wall of the vagina; they are remnants of the mesonephric ducts and very variable in their occurrence. Called also ductus epoophori longitudinales.

haversian canal

see haversian canal.

c's of Hering

openings between the bile canaliculi and the cholangioles, the terminal ducts of the biliary duct system. Called also cholangiole.

hyaloid canal

central canal of the vitreous humor running from the lens to the optic disk.

hypoglossal canal

an opening in the occipital bone, transmitting the hypoglossal nerve and a branch of the posterior meningeal artery; called also anterior condyloid foramen.

infraorbital canal

a canal running obliquely from the front of the orbit to the side of the muzzle, transmitting the infraorbital vessels and nerve. In the horse it passes through the maxillary sinus.

inguinal canal

the oblique passage in the caudal abdominal wall on either side, through which passes the round ligament of the uterus in some females such as the bitch and the spermatic cord in the males.

intestinal canal

small and large intestines.

lacrimal canal

the nasolacrimal canal.

lateral canal

a small canal in the root of a tooth which emerges on the side, rather than the apex. Called also accessory canal.

mandibular canal

a passageway within the mandible for conduction of the inferior alveolar vessels and nerve; the inferior alveolar nerve enters the mandibular canal through the mandibular foramen and exits at the mental foramen supplying nerves to the lower cheek teeth in passing.

medullary canal

1. vertebral canal.

2. the cavity, containing marrow, in the diaphysis of a long bone; called also marrow or medullary cavity.

metatarsal canal

formed by the metatarsal fascia on the plantar aspect of the chief metatarsal bone of the horse; transmits the tendons of the digital flexor muscles.

modiolar canal

in the cochlea of the internal ear; it transmits blood vessels and nerves to the cochlea.

nasolacrimal canal

in the maxilla it transmits the nasolacrimal duct.

nutrient c's

large vascular canals through the cortex of bones. See also haversian canal.

omasal canal

the direct passage through the omasum from the reticulum to the abomasum.

optic canal

a passage for the optic nerve through the cranium into the orbit.

palatine canal

formed by the maxilla and the palatine bone; transmits the palatine artery and nerve.

pterygoid canal

in the basisphenoid bone; contains the pterygoid nerve.

root canal

see root canal.

sacral canal

the part of the vertebral canal through the sacrum.

Schlemm's canal

the venous sinus of the sclera, a circular canal at the junction of the sclera and cornea that receives the aqueous humour. Called also scleral venous sinus.

semicircular c's

the canals (anterior, lateral and posterior) of the bony labyrinth of the ear. See also semicircular canals.

spinal canal, vertebral canal

the canal formed by the series of vertebral foramina together, enclosing the spinal cord and meninges.

supraorbital canal

in the frontal bone; transmits the frontal vein, passing through the zygomatic process to the orbital cavity.

tarsal canal

formed by the plantar annular ligament of the tarsus which roofs over the tarsal groove; transmits the deep digital flexor tendon and plantar vessels.

triosseus canal

the foramen at the junction of the coracoid, clavicle and scapula which transmits the tendon of a flight muscle, the supracoracoideus, in the avian skeleton.

vertebral canal

spinal canal.

Volkmann's c's

canals communicating with the haversian canals, for passage of blood vessels through bone from the periosteum.