anal canal


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Related to anal canal: hemorrhoids, appendix, Ischioanal fossa

canal

 [kah-nal´]
a relatively narrow tubular passage or channel.
adductor canal Hunter's canal.
Alcock's canal a tunnel formed by a splitting of the obturator fascia, which encloses the pudendal vessels and nerve.
alimentary canal see alimentary canal.
anal canal the terminal portion of the alimentary canal, from the rectum to the anus.
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.
carotid canal one in the pars petrosa of the temporal bone, transmitting the internal carotid artery to the cranial cavity.
cervical canal the part of the uterine cavity lying within the cervix.
condylar canal an occasional opening in the condylar fossa for transmission of the transverse sinus; called also posterior condyloid foramen.
canal of Corti a space between the outer and inner rods of Corti.
femoral canal the cone-shaped medial part of the femoral sheath lateral to the base of Gimbernat's ligament.
haversian canal any of the anastomosing channels of the haversian system in compact bone, containing blood and lymph vessels, and nerves.
Hunter's canal a fascial tunnel in the middle third of the medial part of the thigh, containing the femoral vessels and saphenous nerve. Called also adductor canal.
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 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 on either side, through which passes the round ligament of the uterus in the female, and the spermatic cord in the male.
medullary canal
optic canal a passage for the optic nerve and ophthalmic artery at the apex of the orbit; called also optic foramen.
pulp canal root canal.
root canal that part of the pulp cavity extending from the pulp chamber to the apical foramen. Called also pulp canal.
sacral canal the continuation of the spinal canal through the sacrum.
Schlemm's canal venous sinus of sclera.
semicircular c's see semicircular canals.
spinal canal (vertebral canal) the canal formed by the series of vertebral foramina together, enclosing the spinal cord and meninges.
Volkmann's c's canals communicating with the haversian canals, for passage of blood vessels through bone.

a·nal ca·nal

[TA]
terminal portion of the alimentary canal; about 4 cm long, beginning at the anorectal junction, where the rectal ampulla abruptly narrows as the alimentary canal pierces the pelvic diaphragm (levator ani), and ending at the anal verge, when the anoderm that lines the lower anal canal changes to hairy perianal skin; surrounded by the internal and external anal sphincters.
Synonym(s): canalis analis [TA]

anal canal

the final portion of the digestive tract, about 4 cm long, between the rectum and the anus.

a·nal ca·nal

(ā'năl kă-nal') [TA]
The terminal portion of the alimentary canal; it extends from the pelvic diaphragm to the anal orifice.
Synonym(s): canalis analis [TA] .
Enlarge picture
ANAL CANAL

anal canal

The 4 cm long terminal section of the large intestine, beginning where the rectum passes downward and forward through the pelvic diaphragm and ending in the anus. The entire length of the anal canal is surrounded by sphincter muscles, and the canal remains closed except during defecation and passage of flatus.
See: illustration
See also: canal

anal canal

The 5 cm-long terminal portion of the intestine that lies immediately below the RECTUM. The anal canal contains two muscular rings (SPHINCTERS) that can close it tightly and seven or more longitudinal pads of MUCOUS MEMBRANE that contain veins and press together to act as an additional sealing mechanism.

anal

relating to the anus.

anal abscess
acute, purulent infections in the area of the anus, usually caused by gram-negative organisms. In dogs, these most often arise from the anal sacs.
anal atresia, atresia ani
congenital absence or stenosis of the anus manifested by an absence of feces and a gradual development of abdominal distention. Fistulae may develop between the rectum and urogenital tract. The anomalous development can occur in several forms and may be accompanied by similar atresia at higher levels of the intestine. There is usually normal development of sphincters. A dimple is usually evident at the point at which surgical intervention is required.
anal canal
the short, terminal, retroperitoneal segment of the intestinal tract between the rectum and anus.
anal constriction
a congenital constriction combined with vulvar constriction occurs in Jersey cattle.
anal fibroma
occurs in cattle and excision effected for esthetic reasons.
anal fistula
see perianal fistula.
anal fold
see anal fold.
anal furunculosis
see perianal fistula.
anal membrane
the dorsal part of the cloacal membrane in the embryo; when it eventually breaks down the dorsal passage becomes the rectoanal passage.
anal-perineal laceration
see rectovaginal fistula.
anal prolapse
the protrusion of a small amount of mucosa through the anus.
anal reflex
the pursing of the anal orifice when the perineum is stimulated; indicative of an animal with intact sacral segments of the spinal cord.
anal sac
see anal sacs.
Enlarge picture
Anal sacs in the dog. By permission from McCurnin D, Poffenbarger EM, Small Animal Physical Diagnosis and Clinical Procedures, Saunders, 1991
anal sacculitis
inflammation of the anal sacs.
anal sphincter
the internal anal sphincter is formed from smooth muscle of the anal canal while the external anal sphincter, which is larger and of greater importance in fecal continence, consists of striated muscle.
anal sphincter hypertrophy
occurs in aged dogs and may give rise to difficult and painful defecation.
anal stenosis
scar formation after perianal fistulae, trauma, severe anal sac disease, or treatment for neoplasia may result in a reduced lumen and particularly a loss of the capacity to dilate with passage of feces. Straining, passage of ribbon-like feces and constipation result.
anal ulceration
inflammation and ulceration of the perianal skin which may be associated with anal sac disease. Seen most commonly in German shepherd dogs.

canal

a relatively narrow tubular passage or channel.

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.
References in periodicals archive ?
It is uncertain whether the pronounced tendency to metastasize implies a more aggressive tumor biology or is due to plentiful lymphatic and hematogenous channels of the anal canal.
Intraepithelial neoplasia of the anal canal in hemorrhoidal tissue: a study of 19 cases.
The rationale behind injection of carbon-coated beads (200-500 micrometers) is to bulk up the lower anal canal and lower rectum to supplement the function of the internal sphincter.
Another newer treatment is radio-frequency energy delivery to the anal canal, known as the Secca procedure.
They are believed to be the first anal canal cancer patients in the world to be treated using the fast and efficient new technology, which was introduced by Varian earlier this year.
Put a lubed finger into the anal canal and feel for masses.
Physicians who treat patients at the INTEGRIS Cancer Institute of Oklahoma and the ProCure Proton Therapy Center recently developed this new protocol and have successfully treated their first anal canal cancer patient, the first in the country to receive such treatment.
In fact, prolapse of the rectum into the anal canal (hemorrhoidal prolapse) is often the initial and predominant anatomical feature in patients with defecation disorders, said Dr.
The chapters cover CT (computed tomography) colonography, MR (magnetic resonance) colonography, MR imaging of the liver, applications of microbubbles in liver ultrasound, multislice CD for liver imaging, multislice CT angiography of the hepatic and mesenteric vasculature, positron emission tomography of the gastrointestinal tract, evaluation of the small intestine by MR imaging, multiplanar CT enterography, radiofrequency ablation of liver disease, endoscopic ultrasound, imaging rectal cancer, self- expanding metal colonic stents, imaging the anal canal, and dynamic imaging of the pelvic floor.
Whereas EH removes the prolapsed haemorrhoids, it does not address the underlying cause of both mucosal and haemorrhoidal prolapse; conversely PPH, by 'lifting' the prolapsed haemorrhoids and mucosa, re-places the haemorrhoidal cushions high in the anal canal, thus establishing the topographical relationship between the anal cushions and the rectal muscle layer.
A ligation of the rectal mucosa then lifts the hemorrhoid up inside the anal canal.