Abdomen Lecture Notes PDF

The Abdomen Asst. Prof. Sunisa Sirimongkolvorakul (Ph.D) Faculty of Veterinary Medicine, Mahanakorn University of Technology  Objectives Understand anatomical features of abdomen Location Boundaries Relations of differe...

The Abdomen Asst. Prof. Sunisa Sirimongkolvorakul (Ph.D) Faculty of Veterinary Medicine, Mahanakorn University of Technology  Objectives Understand anatomical features of abdomen Location Boundaries Relations of different structures in abdominal cavity Applied basic knowledge to clinical practice  Overview of abdomen Part of the trunk between the thorax and the pelvis It is a flexible, dynamic container, housing most of the organs of the alimentary system and part of the urogenital system  Boundary of abdomen Cranial: diaphragm Caudal: pelvic inlet Dorsal: lumbar vertebrae Lateral: abdominal muscles Superficial structures of abdominal wall Cranial thoracic Caudal thoracic Cranial abdominal Caudal abdominal Inguinal ↳ The mammary glands Present in both sexes Number of glands is determined at a very early stage of mammary development when the animal is a developing embryo Blood supply varies among species but mainly originates from the lateral, internal thoracic and external pudendal arteries Blood supply to the mammillary glands Lateral thoracic artery มดลู ูกอักเ  Organization of abdominal layers Skin Superficial fascia Deep fascia ้นกล้ามเนื ้อ Paralu mbar f ชั os sa Muscular layer สังเก ตจา กลาย muscl External abdominal obliques m. cardalventral Internal abdominal obliques m. ลาย cranioventral Transverse abdominis m. Rectus abdominis m. Transverse fascia Parietal peritoneum  internal abdominal oblique m. transversus abdominis m. rectus abdominis m.  Abdominal viscera Alimentary canals: Esophagus, Small intestine, Large intestine, Anus Accessory organ: Liver, Pancreas Female reproductive organ Nerve Blood vessels Lymph node  Abdomen of the Dog and Cat Cranial boundary of the abdominal wall’s easily determined by palpation of the last rib and costal arch Caudal boundary’s difficult to discover, however the prominence of iliac crest can determined Abdominal cavity is relatively less voluminous than in the large domestic species Distinct midline separation is noted between the left and right mammary chains Superficial inguinal lymph nodes may be palpated in the groin, lateral to the bulbus glandis of the penis Abdominal wall Ventrolateral abdominal wall is constructed according to the common pattern abdominal surgery is frequently performed in dogs and cats, it is necessary to be familiar with the details Linea alba: aponeuroses of the right and left oblique and transverse abdominal muscles extends from the xiphoid process to the pubis and includes the umbilicus at about the level of the third lumbar vertebra incisions through the linea alba spare the muscles, vessels, and nerves  Abdominal wall in each regions Cranial abdominal region Xiphoid region Middle abdominal region Umbilical region Caudal abdominal region Pubic region Visceral topography Organs usually exposed on removal of the abdominal floor are the ventral part of the spleen projecting beyond the left costal arch, a part of liver behind the xiphoid process, and the bladder directly before the pubis Greater omentum: well-developed, folded on itself to form a flat sac between the intestinal mass and the abdominal floor omental bursa lies medial to the caudate process of the liver and is bounded dorsally by the caudal vena cava and ventrally by the portal vein Spleen: elongated, roughly dumbbell-shaped organ that lies more or less vertically against the left abdominal wall Its position is much influenced by the distention of the stomach Serves as an important blood reservoir in the dog and cat, and its size and weight therefore vary widely Visceral projections on the left (A) and right (B) canine abdominal walls. 1, Diaphragm; 2, liver; 3, stomach; 4, spleen; 5, 5 ′, left and right kidneys; 6, descending colon; 7, small intestine; 7 ′, descending duodenum; 8, pancreas; 9, rectum; 10, female urogenital tract; 11, bladder.  Peritoneum and peritoneal compartment A serous membrane line in both abdominal cavity and pelvic cavity Parietal peritoneum, lines abdominal and pelvic wall Visceral peritoneum, lines abdominal and pelvic organs Mesentery: double layers of peritoneum Hold organ in place Store fat Route for vessels and nerve Retroperitoneal: some organs behind peritoneum (eg. kidneys)  Visceral peritoneum Parietal peritoneum Omentum Omental bursa Lesser omentum: connects the lesser curvature of the stomach with liver Greater omentum : descends from the greater curvature of the stomach and covers the intestines, Contains great amount of fat tissue Visceral topography (cont.) Stomach: dog has a relatively modest capacity, ranging from 0.5 to 6.0 L according to breed Cardia lies mainly to the left of the median plane, well forward under cover of the ribs and in direct contact with the liver and the diaphragm Pylorus relative narrow and passes to the right to continue into the duodenum The greater curvature faces mainly to the left, toward the spleen Stomach receives blood from splenic artery supplies short branches as it crosses the caudal surface of the fundus before reaching the spleen left gastroepiploic artery supplies greater curvature left gastric artery supplies the fundus, cardiac region  Carnivore have simple stomach, fundus and body are great expansion, while the pyloric part is less enlarge B, Interior of stomach (dog). 1, cardiac opening; 2, fundus; 3, A, Visceral surface of stomach (dog). 1, cardia; 2, pylorus. body; 4, pyloric antrum. The blood supply of the stomach and spleen, schematic. 1, Aorta; 2, celiac a.; 3, splenic a.; 4, hepatic a.; 5, left gastric a.; 6, indication of the liver; 7, gastroduodenal a.; 8, right gastric a.; 9, cranial pancreaticoduodenal a.; 10, right gastroepiploic a.; 11, left gastroepiploic a.  Small Intestine Relatively short, perhaps three or four times the body length Duodenum: short cranial part of the duodenum passes dorsally and to the right, against the visceral surface of the liver Jejunum and short ileum form a mass occupying the ventral part of the abdomen between the stomach and the urinary bladder Jejunal coils are generally related to the folded greater omentum ventrally Small patches of aggregate lymph nodules of varying sizes are present throughout the small intestine; mostly in the ileum Large intestine Cecum is short, varying length, twisted and joined to the ileum by a short (ileocecal) fold lies to the right of the root of the mesentery and is related to the right kidney dorsally, the descending duodenum Colon slightly wider than small intestine, short ascending part lies to the right while transverse part runs from right to left Pars cranailis duodeni Plica ileocecalis Abdominal viscera of the dog after Ventral view of feline viscera after removal of greater omentum. removal of omentum. 1, Heart; 2, 1, Liver; 2, stomach; 3, spleen; diaphragm; 3, liver; 4, intestine; 5, 4, small intestine; 5, bladder. spleen; 6, bladder. Blood supply of the intestinal tract  Cranial mesenteric artery leaves the aorta caudal to the celiac artery Caudal pancreaticoduodenal artery: runs to the right in the mesoduodenum, supplies the descending duodenum and right lobe of pancreas Jejunal artery: supplies jejunum Ileocolic artery: supplies ileum, cecum Middle colic artery: supplies transverse colon Right colic artery: supplies ascending colon Caudal mesenteric artery Left colic artery: branch runs distally in the descending mesocolon, supplies the descending colon Visceral topography (cont.) Liver Liver is relatively large, and accounts for 3% to 4% of the body weight Ventral border extends across the costal arches and would be palpable were it not for the fat within the falciform ligament Visceral surface, concave, is made irregular by various visceral impressions such as body of the stomach to the left of the median plane Prominent impression, involving the right lateral lobe and caudate process, is made by the right kidney Visceral topography (cont.) Pancreas Left lobe is directed caudomedially and crosses the median plane behind the stomach to end against the left kidney Right lobe is directed caudodorsally and follows the dorsal surface of the descending duodenum within the mesoduodenum Supplies by cranial pancreaticoduodenal artery, pancreatic branch and caudal pancreaticoduodenal artery Two secretory ducts open into the duodenum where two lobes diverge Pancreatic duct Common bile duct Esophagus descending duodenum  Diaphragm A domed sheet of muscle and tendon with a peripheral attachment to the body wall and a free center that bulges cranially Crus arises from lumbar vertebrae Innervation Phrenic nerve unilaterally plus associated pleura and peritoneum Peripheral-lower intercostal nerves The opening goes through the diaphragm Esophageal hiatus Caval foramen Aortic hiatus E.g.: inguinal canal, vascular lacunae and opening of the uterine tube  Abdominal palpation An important diagnostic tool in the examination of dog and cat Abdominal organs may be identified and assessed by palpation through the abdominal wall Normal liver projects only slightly, and variably, behind the costal arches Empty stomach is tucked under the ribs, out of reach on the left side, but when full of ingesta or distended with gas, it projects behind the costal cartilages Spleen occupies the same region against the left flank, but because its usual consistency is soft and deformable Left kidney contacts the dorsal part of the left lateral abdominal wall Intestinal mass occupies a large part of the abdomen, extending from the roof to the floor and from one flank to the other Lymph nodes associated with the intestine evade detection unless enlarged A, Male dog, left lateral view. 1. Left lung 9. Rectum B, Female dog, right lateral view. 2. Heart 10. Greater omentum covering small intestine 1. Right lung 8. Urethra 3. Liver 11. Spleen 2. Heart 9. Rectum 4. Stomach 12. Descending colon 3. Liver 10. Greater omentum covering small intestine 5. Left kidney 13. Ductus deferens 4. Stomach 11. Descending duodenum 6. Ureter 14. Left testis 5. Right kidney 12. Right uterine horn 7. Bladder 15. Prostate 6. Ureter 13. Right ovary 8. Urethra 7. Bladder 14. Vagina  Abdominal topography Radiographs of the abdomen generally reveal few details of the stomach beyond the gas that naturally collects in the uppermost part of the organ: the fundus More complete demonstration of the topography is obtained with the administration of a barium meal Lateral (A) and ventrodorsal (B) radiographic views of the canine abdomen. 1, Liver; 2, pyloric part of stomach; 2 ′, descending duodenum; 3, spleen; 4, os penis; 5, cecum; 6, fundus of stomach; 7, left kidney; 8, bladder.  Transverse section of the canine trunk Fundus of stomach Caudal vena cava Body of stomach Pyloric part of stomach Gallbladder Fat-filled falciform ligament;  Computed tomographic (CT) image Caudal vena cava Liver Stomach Hepatic portal vein  Abdomen of the horse Horse has a capacious gastrointestinal tract and a correspondingly bulky abdomen Abdominal conformation varies much with age, condition, and the amount and nature of the rations Trunk is broadest at the last ribs Transverse processes of the lumbar vertebrae are usually too deeply buried under muscle to be palpable Subiliac lymph nodes can be identified at the cranial margin of the thigh The abdominal muscles and their skeletal attachments. 1, External abdominal oblique, muscular part; 2, aponeurotic parts of 1, 5, and 7; 2 ′, 2 ″, pelvic and abdominal tendons of aponeurotic part; 3, superficial inguinal ring; 4, attachment of pelvic tendon of external oblique aponeurosis on iliopsoas and sartorius (“inguinal ligament”); 5, internal abdominal oblique, muscular part; 5 ′, free caudal border forming the cranial margin of the deep inguinal ring; 6, iliopsoas, partly enclosed by iliac fascia; 7, transversus abdominis, muscular part; 8, rectus abdominis; 8 ′, tendinous inscriptions. a, Sternum a ′, xiphoid cartilage a ″, costal arch b, rectus abdominis b ′, rectus sheath c, internal oblique d, linea alba; d′, prepubic tendon e, cutaneous trunci f, pectoralis ascendens f ′, diaphragm g, skin g ′, fat h, superficial inguinal lymph nodes i, penis i ′, prepuce i ″, scrotum. Stomach of the horse Remarkable small size in relation to the animal and to the volume of fodder consumed Lies mainly within the left half of the abdomen Near the fundus found saccus cecus (blind sac) Stepped edge (margo plicatus) divides a large non-glandular region, occupying the fundus and part of the body, and a glandular region A, Interior of the stomach and cranial part of the duodenum. 1, Esophagus; 2, cardiac opening; 3, fundus (blind sac); 4, margo plicatus; 5, body; 6, pyloric part; 7, pylorus; 8, cranial part of duodenum; 9, major duodenal papilla within hepatopancreatic A, ventral fundus, B, cardia; C, pylorus; D, dorsal fundus ampulla; 10, minor duodenal papilla. (Martineu et al., 2009) Spleen Spleen lies within the left dorsal part of the abdomen which protected by caudal ribs Broad dorsal base lies under the last three ribs, although a small corner may project against the flank position of the spleen naturally varies with respiration Its muscular capsule, which allows much variation in volume because the spleen becomes engorged when the capsule is relaxed  Topography of spleen, stomach, pancreas, and liver, caudoventral view. 1, Renal surface; 2, intestinal surface; 3, gastric surface; 4, greater omentum (gastrosplenic ligament); 5, splenic artery and vein; 6, renosplenic ligament; 7, phrenicosplenic ligament. The intestines The intestines occupy the greater part of the abdominal cavity Provides the reservoir for microbial fermentation Small intestine is unremarkable, but the large intestine is greatly modified and enlarged Duodenum is relatively short Bile and pancreatic ducts discharge through a single papilla within an enclosure Jejunum lies within the free margin of the great mesentery Ileum is very short, and in most circumstances it is distinguished from the remainder of the small intestine by its much thicker wall and firmer consistency The intestinal tract seen from the right, schematic. The caudal flexure of the duodenum and the cranial mesenteric artery (17) have been displaced to the right of the animal to lie over the base of the cecum. 1, Stomach; 2, 3, descending and ascending duodenum; 4, jejunum; 5, ileum; 6, cecum; 6 ′, cecocolic fold; 7, right ventral colon; 8, ventral diaphragmatic flexure; 9, left ventral colon; 10, pelvic flexure; 11, left dorsal colon; 12, dorsal diaphragmatic flexure; 13, right dorsal colon; 13 ′, ascending mesocolon; 14, transverse colon; 15, descending (small) colon; 16, rectum; 17, cranial mesenteric artery.  Visceral projections on the left abdominal wall (including the diaphragm) 1, Cut edge of diaphragm; 1′, rib 6; 2, stomach; 3, liver; 4, spleen; 5, descending colon (banded); 6, jejunum (smooth); 7, left dorsal colon; 8, left ventral colon. The intestines (cont.) Large intestine characterized by having a sacculated form/ haustra arrange of the large intestine of the horse predisposes to various forms of obstruction and displacement, conditions collectively known as colic Cecum Consists of an expanded dorsal base, a curved tapering body, and a blind ventral apex A comma shaped like Base lies in the right dorsal part of the abdomen, partly against the flank Microbial fermentation within the cecum produces gas that is normally discharged Visceral projections on the right abdominal wall (including the diaphragm). 1, Cut edge of diaphragm; 1’, rib 6; 2, liver; 3, right kidney; 4, descending duodenum; 5, body of cecum; 6, right ventral colon; 7, right dorsal colon. Colon Right ventral colon is narrow, siphon-like arrangement but soon expands to continue, first ventrally, then cranially on the abdominal floor Left ventral colon runs toward the pelvis, still on the abdominal floor. Its reach till pelvic flexure Left dorsal colon is narrow and smooth-walled where it emerges from the pelvic flexure, but it gradually widens; the teniae increase, continues to diaphragmatic flexure Right dorsal colon ascends below the liver to meet the cranial part of the cecal base by which it becomes the transverse colon Right ventral colon Sternal flexure Left ventral colon Pelvic flexure Left dorsal colon Diaphragmatic flexure Right dorsal colon 1, Xiphoid cartilage; 2, body of cecum; 3, apex of cecum; 4, right ventral colon; 5, ventral diaphragmatic flexure; 6, left ventral colon; 7, dorsal diaphragmatic flexure Liver Liver is quite variable in form and size but on average weighs about 5 kg in a saddle horse, thus accounting for about 1.5% of the body weight Parietal surface is joined to the diaphragm by a complicated system of ligaments Visceral surface lies against and is impressed by the stomach The duct system is remarkable for the absence of a gallbladder bile duct opens into the cranial duodenum on the papilla shared with the major pancreatic duct  Portal v. caudal vena cava hepatic a. Ruminant  Abdominal wall of the ruminant Abdomen varies with age, obesity, and physiological condition In adult animals it is both deep and wide, and the floor, which dips behind the sternum Lateral and ventral abdominal walls are bounded by the last rib and costal arch, the extremities of the lumbar transverse processes, the coxal tuber, and the terminal line of the pelvic inlet Palpation should be performed with care because correct identification of the bones is important in certain anesthetic techniques the second to fifth vertebrae is easy and may even be possible without palpation in lean cattle Innervation and vascularization of abdominal wall The important nerves of the abdominal wall are the last thoracic (T13) and the first and second lumbar nerves Topography and distribution of the nerves to the flank is of practical importance in obtaining local anesthesia skin of the abdomen is supplied by branches from both dorsal and ventral primary rami, but the muscles and other deep structures are supplied by ventral rami alone Abdominal wall receives blood vessels from several sources ventral part supply through the cranial and caudal epigastric arteries flanks are supplied by deep circumflex iliac artery which the most important surgically 1, Last rib; 2, spinous process of L2; 3, coxal tuber; 4, twelfth intercostal n. (T12); 5, T13 (costoabdominal n.); 6, L1 (iliohypogastric n.); 7, L2 (ilioinguinal n.); 8, L3, L4 (genitofemoral n.); 9, L5 (nerve); 10, ventral perineal n. Stomach Stomach is composed of four chambers—rumen, reticulum, omasum, and abomasum—through which the food passes successively Topography of the ruminant abdomen is dominated by the enormous development of the stomach, which in adult cattle almost fills the left half of the cavity and occupies a substantial portion of the right Its capacity various chambers as follows: rumen, 80%; reticulum, 5%; omasum, 8%; and abomasum, 7% (cattle) Rumen lies above the middle of the 7th intercostal space or 8th rib to the pelvic inlet, and from the left body wall across the midline Stomach (cont.) Direct contact of the dorsal sac of rumen with the upper part of the left flank makes auscultation and palpation simple Rumen and reticulum are intimately related in structure and function rumen and reticulum communicate over the U-shaped ruminoreticular fold Cattle sometimes ingest foreign bodies, especially pieces of wire, with their forage when sharp, may be driven through the reticular wall by the contractions of this organ (traumatic reticulitis or “hardware disease”) The relationships are contact between reticulum and the diaphragm and liver cranially; implication of the abomasum between the two chambers (ventral sac of rumen and reticulum) ventrally The relation of the right surface of the rumen to the intestinal mass, omasum, abomasum, pancreas, and kidneys  Dorsal sac of rumen Caudodorsal blind sac of rumen Spleen Reticulum Abomasum Caudoventral blind sac of rumen covered by omentum Descending duodenum Omasum covered by lesser omentum Abomasum  1, Aorta: 2, caudodorsal blind sac; 3, dorsal coronary pillar; 4, caudal 1, Spleen; 2, crura of diaphragm; 3, atrium ruminis; 4, cranial pillar; pillar; 5, left longitudinal pillar; 6, ventral coronary pillar; 7, 5, abomasum; 6, omasoabomasal opening; 7, omasum; 8, portal vein; caudoventral blind sac; 8, descending duodenum; 9, left kidney; 10, 9, liver; 10, caudal vena cava; 11, right lung; 12, aorta. caudal vena cava; 11, milk vein; 12, intestinal mass.  Regurgitation of food for remastication requires the coordination of the stomach movements with those of the thoracic wall and throat Materials within the rumen partition into three primary zones based on their specific gravity Gas rises to fill the upper regions grain and fluid-saturated roughage sink to the bottom newly arrived roughage floats in a middle layer A cycle of contractions occurs 1 to 3 times per minute, highest frequency is seen during feeding, and the lowest when the animal is resting Ruminant’s intestine Lies almost entirely to the right of the midline, packed mainly into the dorsal part of the abdomen Duodenum Takes origin below the ribs Runs toward the pelvis as the descending duodenum but turns when almost level with the coxal tuber Duodenocolic ligament is placed where ascending duodenum meet to descending colon Jejunum forms many short coils within the free margin of the mesentery Ruminant’s intestine (cont.) Ileum is defined by the ileocecal fold Cecum continues into the colon without obvious change in diameter; the junction is marked only by the entrance of the ileum Colon is divided into the usual ascending, transverse, and descending parts Two centripetal turns are succeeded by two centrifugal turns that restore the colon toward the periphery of the mesentery 1, Pyloric part of abomasum; 2, duodenum; 3, jejunum; 4, ileum; 5, cecum; 6, ileocecal fold; 7-10, ascending colon; 7, proximal loop of ascending colon; 8, centripetal turns of spiral colon; 9, centrifugal turns of spiral colon; 10, distal loop of ascending colon; 11, transverse colon; 12, descending colon; 13, rectum; 14, jejunal lymph nodes; 15, cranial mesenteric artery. bulk of the intestines is supplied by the cranial mesenteric artery  Spleen and liver Flat oblong spleen is situated over the craniodorsal part of the rumen, against the left half of the diaphragm spleen has a relatively soft consistency Its color varies considerably, tending to be steel blue in cows and more reddish in males and younger animals Liver reaches its adult size by the third year and after that its weight vary depending on breed, age, and nutritional condition liver of the adult animal lies almost entirely within the right half of the abdomen, related to the caudal face of the diaphragm and under cover of the ribs liver receives blood from the hepatic artery and portal vein, which enter at the porta liver is retained in position by certain ligaments attaching it to the diaphragm and, more importantly, by visceral pressure Visceral surface of the bovine liver 1, Left lobe; 1′, omasal impression; 2, quadrate lobe; 3, right lobe; 4, 4 ′, papillary and caudate processes of caudate lobe; 5, round ligament; 6, left triangular ligament; 7, right triangular ligament; 8, caudal vena cava; 9, right kidney; 10, portal vein; 11, hepatic lymph node; 12, bile duct; 13, cystic duct; 14, gallbladder. Spleen (Boos et al., 2013) The flat oblong spleen is situated over the craniodorsal part of the rumen relatively soft consistency color varies considerably, tending to be steel blue in cows and more reddish in males and younger animals  sheep goats spleens of cattle 1: Splenic artery  Lymph nodes of the abdominal roof A number of important lymph nodes are scattered among abdominal viscera Cranial mesenteric and celiac ln. lie at the origin of the cranial mesenteric a. Jejunal ln. are in the mesentery of the jejunum and ileum Examined in meat inspection Colic ln. are most numerous on the right surface of the spiral loop; others are present on the proximal and distal loops Caudal mesenteric ln. are on the sides of the descending colon The lymph drainage goes into the cisterna chyli A Celiac and cran. mesenteric lnn. B Caud. mesenteric lnn. C Colic lnn. D Cecal lnn. E Jejunal lnn. F Aortic lumbar lnn. G Proper lumbar lnn. H Renal lnn. I Pancreaticoduodenal lnn. K Anorectal lnn. L Gastric trunk M Hepatic trunk N Intestinal trunk O Cisterna chyli P Thoracic duct Q Lumbar trunk R Visceral trunk  The abdomen of the pig A thick layer of subcutaneous fat obscures most underlying features of the trunk The cutaneous muscle of the trunk is extensive as well as thick ventrally where it passes through the flank fold Stomach of the pig Simple type, presenting fundus, corpus, and a pyloric part Cranially related to the liver and diaphragm Unique feature among domestic species is the presence of a conical diverticulum projecting caudally from the fundus Spleen Its bright red, elongated, and straplike spleen is oriented more or less vertically under the protection of the caudal ribs on the left side It follows the greater curvature of the stomach to which it is loosely attached by a gastrosplenic ligament Pig’s intestine Small intestine Duodenum is arranged like that of the dog, descending toward the pelvis before turning to run forward to the left of the root of the mesentery before dipping ventrally to be continued by the jejunum Jejunum is arranged in many small loops suspended by a mesentery Large intestine referred as cecocolic junction cecum and colon must be considered together as combine in a conical 1, Aorta; 2, caudal mesenteric artery; 3, cranial mesenteric 1, Descending duodenum; 2, caudal flexure of duodenum; 3, jejunum; 4, artery; 4, celiac artery; 5, ileum; 6, cecum; 7, ascending ileum; 5, cecum; 6, ascending colon; 7, transverse colon; 8, descending colon; 8, transverse colon; 9, descending colon; 10, rectum. colon; 9, descending mesocolon; 10, mesoduodenum; 11, mesentery.  Liver The liver resembles that of the dog in position and lobation divided by deep fissures into left lateral and medial lobes and right medial and lateral major lobes, supplemented by a smaller quadrate lobe and caudate process  References Boos, A., Geyer, H., Müller, U. et al. Situs ambiguus in a Brown Swiss cow with polysplenia: case report. BMC Vet Res 9, 34 (2013). de Lahunta Alexander and Robert E. habel 1986 Applied Veterinary Anatomy W.B.Sauders Company Philadelphia ,U.S.A. 330 pp. Dyce K.M., W.O. Sack and C.J.G. Wensing, 1987, Textbook of Veterinary Anatomy, W.B.Sauders Company, Philadelphia, U.S.A.,820 pp. Martineau, H., Thompson, H., and Taylor, D. (2009). Pathology of gastritis and gastric ulceration in the horse. Part 1: Range of lesions present in 21 mature individuals. Equine Veterinary Journal, 41(7), 638– 644.