Anatomy report about The digestive system In The Ruminant The digestive system is composed of the : (1) The Mouth (2) The Esophagus (3) The Stomach (and its compartment) (4) The Intestine (and its division) (5) The Accessory organs which is ** The Liver ** The Spleen ** The Pancreas The Mouth **It is divide to : 1-vestibule : Is the cavity laying outside the teeth and the gum and inside the lips and cheeks 2-mouth(oral) cavity : Is bounded dorsally by the hard palate and ventrally by the tongue and craniolateral by the dental arches and caudoventral by the palatogloossal arch **There is no incisor teeth in the upper jaws instead of it there is the Dental pads **The lips of the small ruminant are much more mobile than those of the cattle. The Tongue **Is very large and it is have a transverse lingual fossa,which food tends to collect **It is have a several papilla : (1) Filiform papilla:freely spread over the apex While conical and flat lenticular papilla are present up on the torus (the tongue root) (2) Fungiform papilla: are scattered on the apex (3) Vallate papilla : present in the torus (For taste ) **The oral floor below the apex of the tongue presence a fleshy sublingual crancle of each side . (4) Buccal papilla :its out the tongue and it is located in the upper and lower jaws behind the dental pad and the incisor teeth respectively (most prominent toward the corners of the mouth) The Dentition Formula The Temporary Teeth: 0-0–3 3-1–3 The Permanent Teeth: 0-0-3-3 3-1-3-3 Salivary Gland **There are three major salivary gland (1) The Parotid Gland : It is continuously active and small,it lies ventral to the ear along the caudal boarder of masseter m , where it partly covered the parotid lymph node, and it is duct are palpated in the vascular notch in the mandible (2) The Mandibular Gland : It is larger than the parotid gland and it produces a mixed secretions but only when the animal is feeding or remasticating,the gland extend in an arch on the inner aspect of the lower jaw,the duct runs below the oral mucusa to open by the sublingual caruncle Salivary Gland (3)The Sublingual Gland :It has Two division: 1-The polystomatic part: it lies in the mouth floor lateral to the tongue and drains though many small openings beside the lingual frenulum 2-The monostomatic part: it compact,rostral has a single duct opens with the mandibular Gland in the sublingual caruncle. The pharynx **The pharynx is divided to : (1) Nasopharynx (2) Oropharynx (3) Laryngopharynx The Esophagus : **Is a muscular tube leading from the mouth to the reticulum and rumen.contraction of muscle causes feed boluses to be moved down to the reticulum or up during the process of regurgitation and rumination. The stomach **Its is composed of four chambers: rumen ,reticulum ,omasum , abomasum. **The first three known as the forestomach, are developed to cope with the complex CHO, and only the last chamber is comparable in structure and function to the simple stomach. **The four chambers capacity are (60L) and its percentage in : *Large ruminants : Rumen 80% , Reticulum 5%,, Omasum 8%,, and Abomasum 7%. *Small ruminants : Rumen 75% , Reticulum 8%,,Omasum 4%,, and Abomasum 13% The rumen and reticulum *The Rumen extend from cardia to the pelvic inlet, and from the abdominal roof to the floor, and form the left body wall across the midline specially caudally and ventrally where it may reach the lower right flank. *The Reticulum lies cranial to the rumen and mainly to the left of the median plane, and it lies above the xephoid process of the sternum. **The rumen and reticulum communicate over the ruminoreticular fold. Ruminal Papilla Reticular Papilla The omasum **It lies within the intra thoracic part of the abdomen to the right of the midline and between the rumen and reticulum to the left, and the liver and body wall to the right. **It is bilaterally flattened and displays along convex border **Most of it lies under cover of ribs 8-11. The omasum **The anterior is occupied by about 100 crescentic laminae that arise from the sides and greater curvature and projects towards the lesser curvature where there is a more open passage (the omasul canal) **The reticulo-omasul orifice is situated at the upper end of the short cannel ** In sheep and goats : The omasum is relatively smaller Omasal Folds Abomasum **It lies flexed upon the abdominal floor embracing the lower pole of omasum from behind. **It is divided by analogy with the simple stomach into fundus and body. **The narrower and more uniform distal limb constitutes the pyloric part ***The abomasum does not usually come into contact with the liver in adult cattle. **The abomasum is lined by a pink slime-covered, glandular mucosa which is in striking contrast to the harsh lining of the fore stomach. The omentum **The attachment of the greater omentum begins dorsal to the esophagus. The two serosal sheets of which it is composed pass directly into the rumen but are so widely separated that the immodestly post cardiac part of the rumen roof is left bare. **The lesser omentum arises from the visceral surface of the liver between the porta and the esophageal impression and passes to the region of the reticular groove, the right place of omasum , and then along the lesser curvature of the abomasum to the first part of the duodenum which returns it to the liver. The omentum **The omental sheets enclose a space (omental bursa is an important store of fat) which is completely divided from the greater peritoneal cavity except at the epiploic foramen (bursal foramen) near the portal of the liver. Digestive system of horse Dental Formula Temporary teeth: = I3C0P3M0 I3C0P3M0 Teeth • Permanent teeth =36-42 = I 3 C 1 (0) P 3 (4) M 3 I 3 C 1 (0) P 3 M 3 In the female horse , no canine teeth - 1st premolar (wolf tooth); fail to developed, if developed its vestigial. The stomach • B. Horse – – – – – 2 simple composite stomach Cardia Fundus Body pylorus 1 5 3 4 The intestine • Small intestine – Duodenum – Jejunum – Ileum • Large intestine – Cecum – Colon – Rectum Small intestine • Proximal in most spices the principal organ of digestion and absorption • continuous three part - Duodenum - which is short and rather closely fixed in position attached to abdominal roof by mesoduodenum Jejunum and ileum - Which are carried by the greater mesentery - Less closely fixed in position Large intestine • Distal large intestine • Mush short and especially concerted with the dehydration of food residue • Comprises of three parts - Cecum is the blind ending - Colon - Rectum • Cecum - at junction of ileum and ascending colon • huge, comma shaped in horse - consists of a base, body and apex • Colon contain three part ascending transverse descending • The rectum joins the short anal canal 10 3 6a 2 5 6b 4 6c 4 4 6 • Ascending colon - in horse, also called the great colon - made up of: a. right ventral colon - extends cranially on right ventral floor to sternum b. Sternal flexure - connection between right and left ventral colons, curving around apex of Cecum c. left ventral colon extends caudally on left ventral floor 10 3 6a 2 5 6b 4 6c 4 4 6 • Ascending colon (cont.) - made up of: d. Pelvic flexure- connection of left ventral colon and left dorsal colon in left paralumbar fossa e. Left dorsal colon- continuation of pelvic flexure cranially on top of the left ventral colon against the left abdominal wall 10 3 6a 2 5 6b 4 6c 4 4 6 Ascending colon (cont.) - made up of: F . Diaphragmatic flexure connection of left dorsal colon and right dorsal colon G. Right dorsal colon- continuation of diaphragmatic flexure caudally on top of the right ventral colon against the right abdominal wall 10 3 6a 2 5 6b 4 6c 4 4 6 • Transverse colon – heads transverse right to left cranial to cranial mesenteric artery • descending colon – heads caudal to left of cranial mesenteric artery connects transverse colon with rectum – also called small colon 10 7d 10 7c 7c 3 7e 3 2 5 7b 7a 4 2 5 7b 4 7a 4 4 VIII. Large Intestine B. Horse 7 4 VIII. Large InHorse 7 4 Bovine intestine The Omentum • A double-layered connecting peritoneum between the stomach and abdominal organs or abdominal wall 1- Lesser omentum – connect lesser curvature of the stomach and first part of duodenum to the porta of the liver • Gastrohepatic ligament • Hepatoduodenal ligament The Omentum 2- Greater omentum – Connect the greater curvature of the stomach to the dorsal abdominal wall • Superficial leaf: extend from the stomach caudally to pelvic inlet where it reflect and returns cranially as the deep leaf • Deep leaf attaches to the dorsal abdominal wall and contains the left lobe of the pancreas between its peritoneal layers The omentum (bovine) – The lesser omentum arises from the visceral surface of the liver between the porta and the esophageal impression and passes to the region of the reticular groove, the right place of omasum , and then along the lesser curvature of the abomasum to the first part of the duodenum The omentum (bovine) The greater omentum has two leaves as in the other species: • Superficial leaf arises from the left side of the rumen and deep leaf arise from the right side of rumen. – Both leaves extend ventrally and to the right, both leaves ascend together along the right abdominal wall to attach to the descending duodenum. – Superficial leaf: attaches the greater curvature of the abomasum and descending duodenum, it extends along the ventral abdominal wall to the left side to attach to the left longitudinal groove of the rumen. – Deep leaf: extends from the right longitudinal groove of the rumen to the descending duodenum Omental bursa • The omental sheets enclose a space (omental bursa is an important store of fat. – It is completely divided from the peritoneal cavity except at the epiploic foramen (bursal foramen) near the portal of the liver.