Previously we discussed about various exocrine glands in and foramen in animals. This topic covers about various principle ducts and canals present in animal body and their location and their functios. ANAL CANALLocation: Rectum of Mammals Function: It extends from the pelvic floor downward and posteriorly to the anus. BIDDER’S CANALLocation: Frog’s kidney sperms.Function: It connects testis to kidney and conducts BILE DUCTLocation: VertebratesFunction: It runs from gall bladder to duodenum through which bile flows. CANAL OF SCHLEMNLocation: Mammalian eyeFunction: It lies near the junction ofcornea and sclera, this canal passes circularly around the cornea, and drains the aqueous humour. CENTRAL CANAL (CEREBROSPINAL CANAL)Location: Spinal cordFunction: It is situated in the centre of gray matter and extends entire length of the cord. Cerbrospinal fluid flows in it. CERVICAL CANALLocation: UterusFunction: Canal of cervix of uterus COCHLEAR CANAL (SCALA MEDIA)Location: Internal ear of mammalsFunction: It is middle canal in the cochlear duct filled with peri lymph COLLETING DUCTLocation: Kidney of mammalsFunction: These are many and collect urine. CYSTIC DUCTLocation: part of bile duct in vertebrates,Function: which leads from gall bladder receives branches from various part of the liver and it eventually forms the common bile duct. DUCT OF RIVINUSLocation: Salivary glands of mammalsFunction: Ducts of sublingual glands (Sublingual ducts) lie just beneath the floor of the mouth and open into the floor qf the mouth. ENDOLYMPHATIC DUCTLocation: Internal ear of mammalsFunction: It is a small short duct connected with saccule and end blindly in the endo lymphatic sac. EUSTACHWN TUBE (AUDITORY TUBE)Location: Middle ear of all land vertebratesFunction: It connects middle ear with pharynx. HAVERSIAN CANALSLocation: BonesFunction: These are longitudinal canals found characteristically in long bones. HEPATIC DUCTLocation: Liver of vertebratesFunction: It originates from liver cells and unites with the cystic duct from the gall bladder to form the common bile duct. HYALOID CANALLocation: Eye of mammalsFunction: It extends between optic disc and the lens. INGUINAL CANALLocation: Reproductive organs of male mammal.Function: It connects abdominal cavity to scrotal cavity. LACRIMAL DUCTSLocation: Eyes of manFunction: These are two (superior and inferior) connect lacrimal gland with lacrimal sac. LACTIFEROUS DUCTSLocation: Mammary glands of placentalsFunction: These carry milk from mammary glands to the tip of LAURER’S CANAL (LAURER STIEDA CANAL)Location: Reproductive organs of liver flukeFunction: It is temporary copulatory canal which opens on the dorsal body surface. LYMPHATIC DUCT RIGHTLocation: Thorax of vertebratesFunction: It is a short duct receives lymph from the right side of the head, the right upper extremity and the right side of the thorax. MANDIBULAR CANALLocation: Lower jaw of mammalsFunction: It originates from mandibular foramen for in- ferior alveolar vessels and nerve and lies on the inner surface of each ramus. NASOLACRIMAL DUCTLocation: NoseFunction: It connects lacrimal sac with inferior nasal meatus. NEURENTERIC CANALLocation: Vertebrate embryoFunction: It is a canal joining the primitive gut with the cavity of neural tube. PANCREATIC DUCT (DUCT OF WIRSUNG)Location: PancreasFunction: The duct which conducts enzymes from the pancreas into the duodenum. PAPILLARY DUCT (DUCT OF BELLINI)Location: Kidney of mammals (part of renal tubule)Function: These open on the tip of renal papilla and pour their contents into a minor calyx of the renal pelvis. PAROTID DUCT (STENSON’S DUCT)Location: Salivary gland of mammalsFunction: It passes anteriorly to pour into the yes- tibule of the mouth, opposite the upper second molar tooth. SEMICIRCULAR DUCTS (CANALS)Location: Internal ear of vertebratesFunction: These are filled with endolymph and concerned with equilibrium. SUBMAXILLARY DUCT (WHARTON’S DUCT)Location: Salivary gland of mammalsFunction: It extends from the anterior end of each submaxillary gland and opens into the floor of the mouth on each side of the frenulum. THORACIC DUCTLocation: Thorax and Abdomen of mammalsFunction: The chief collecting duct of lymphatic system receive lymph from lacteals. It lead towards left subclavian THYROGLOSSAL DUCTLocation: On the floor of pharynx in mammalsFunction: An embryonic duct between thyroid and pharynx. it disappears in adults. VERTEBRATERIAL CANALSLocation: Cervical vertebrae of mammals, birds and reptilesFunction: These canals are found at the base of transverse processes of cervical vertebrae for the passage of cervical blood vessels and nerves. VOLKMANN’S CANALLocation: Long bones of mammalsFunction: These are transverse canals, connecting Haversian canals. These carry blood.