Small Animal Abdomen (Canine & Feline) PDF

Small Animal Abdomen (Canine&Feline) Cristian Dezdrobitu, DVM, MSc, PhD Abdominal cavity Cranial border- diaphragm muscle...

Small Animal Abdomen (Canine&Feline) Cristian Dezdrobitu, DVM, MSc, PhD Abdominal cavity Cranial border- diaphragm muscle Caudal border- pelvic inletCenter Bounded by muscle and bone Dorsal border- vertebrae, sublumbar Lined by serous membranes muscles, crura of diaphragm Contains viscera Lateral sacral promontory Intrathoracic = ribs and costal arch, intercostal mm. Extrathoracic = muscles of the abdominal wall Ventral - rectus abdominis muscle Nickel et al. The Viscera of Domestic Mammals, 2nd Ed. Verlag Paul Parey, p. 2. Topographic regions of thorax and abdomen. GDD (8th Edition), Evans and de Lahunta. Clinically Oriented Anatomy of the Dog and Cat (2nd Edition), M.S.A Kumar.  Craniodorsal Quadrant: Caudodorsal Quadrant: Phrenicoabdominal a. (caudal Deep circumflex iliac a. (arises from the aorta) Blood Supply phrenic a. and cranial abdominal a.) (arises from the aorta) suffid misd on sops https://veterian key.com/periton GDD, Figure 4-33 eum-and- retroperitoneum Caudoventral Quadrant: Cranioventral Quadrant: / Caudal epigastric a. Cranial epigastric a. Caudal superficial epigastric a. Cranial superficial epigastric a. DORSAL X Craniodorsal Quadrant: Phrenicoabdominal a. (caudal phrenic a. and cranial abdominal a.) CRANIAL VENTRAL CAUDAL Cranial abdominal a. Caudal phrenic a.  DORSAL CAUDAL Deep circumflex CRANIAL iliac a. Medial iliac lymph node VENTRAL Caudodorsal Quadrant: Deep circumflex iliac a. AORTA Reflected sternum Cranioventral Quadrant: Cranial epigastric a. Cranial superficial epigastric a. Internal thoracic a. Cranial epigastric a. (branch of internal thoracic a.)  CAUDAL Caudoventral Quadrant: Caudal epigastric a. Caudal superficial epigastric a. Ventral abdominal wall - reflected CRANIAL Caudal epigastric a.  CRANIAL External pudendal a. CAUDAL DORSAL RECUMBENCY Spermatic cord Caudal superficial epigastric a. Caudoventral Quadrant: Caudal epigastric a. Caudal superficial epigastric a.  Blood supply to the mammae Internal thoracic a. Cr. epigastric a. Cr. superficial epigastric a. External pudendal a. Caudal superficial epigastric a.  Innervation (nerve supply) Ventral branches (medial and lateral branches) of spinal nerves T13 – L4 supply innervation to the walls of the abdominal cavity. Lateral cutaneous branches (out of the lateral branches) dealmost w sensory Iao see between E AO are Medial branches See intransversus  Lumbar Spinal Nerves The ventral branches of lumbar spinal nerves (and T13) innervate the abdominal wall: dying a) Costoabdominal n. (T13) c b a e d b) Cranial iliohypogastric n. (L1) c) Caudal iliohypogastric n. (L2) nextor d) Ilioinguinal n. (L3) e) Lateral cutaneous femoral n. (L3/L4) ventral a costal wall These nerves are d c b visible on the lateral surface of transversus caudal cranial abdominis m. dorsal Guide to the Dissection of the Dog, 8th ed.; Evans and de Lahunta, Fig. 4-3  The abdominal aorta has several paired arterial branches Lumbar aa. (segmental) Phrenicoabdominal aa. Renal aa. Testicular/ovarian aa. o a Deep circumflex iliac aa. External iliac aa. Internal iliac aa. o me CRANIAL CAUDAL AORTA Lumbar aa. KIDNEY AORTA Renal a. KIDNEY  Testicular a. CAUDAL CRANIAL AORTA Vaginal ring Ureter DORSAL RECUMBENCY Deferent duct  CAUDAL FYI – you will be responsible for this info in GA II course. Internal iliac aa. External iliac aa. CRANIAL DORSAL RECUMBENCY AORTA Median sacral a.  Peritoneum Mesothelial layer divided into 3 regional components: – Parietal peritoneum- lines the body wall – Visceral peritoneum- covers the organs – Connecting peritoneum (mesenteries, omenta or ligaments)- double sheets extending between connecting parietal to visceral parts  Peritoneum Dashed line = parietal Solid line = visceral Double line = connecting µ Connecting peritoneum Omentum (extended mesogastrium) - attaches the stomach to the body wall or other organs. Greater omentum - attaches the greater curvature of the stomach to the dorsal body wall. From the stomach it extends caudally as the superficial leaf between the jejunum and the ventral abdominal wall. Turns dorsally on itself near the pelvic inlet and returns as the deep leaf dorsal to the stomach where it contains the left lobe of the pancreas between its peritoneal layers. Mesoduodenum - Origin: dorsal abdominal wall and root of the mesentery. Extends - duodenum. Encloses the right lobe of the pancreas. It is continuous with the mesentery of the jejunum (mesojejunum). The ascending duodenum is secondarily attached to the mesocolon of the descending colon by the duodenocolic fold. The mesentery (mesojejunoileum) - Attachment: abdominal wall opposite the second lumbar (L2) vertebra by a short peritoneal attachment named the root of the mesentery. Continues with the mesocolon (connects the colon to the dorsal body wall). Lateral ligaments of the urinary bladder - contain the remnants of the umbilical arteries = round ligaments of the bladder and the distal part of the ureters. The remnants of the umbilical arteries are the round ligaments of the bladder. Connecting peritoneum Falciform ligament - fold of peritoneum - from the umbilicus to the diaphragm m. Also, attached to the liver (between left medial and quadrate lobes). Characteristics: - fat (especially in obese specimens) - round ligament of the liver (remnant of the umbilical vein) - young animals - visible in the free border of the falciform ligament. Lutusible in old art Median ligament of the urinary bladder - the fold of peritoneum caudal to the umbilicus - urachus and umbilical arteries (in the free border of the median ligament of the UB) in the fetus. Lesser omentum - from the lesser curvature of the stomach to the porta (vena) of the liver. Liver and cardia of the stomach - attaches to the diaphragm. It covers the papillary process of the liver. Attaches the liver to the duodenum (hepatoduodenal lig.). Contains the: portal vein, hepatic a. and bile duct. The greater omentum (epiploon) has superficial (14) and deep (13) leaves and these enclose a space called the omental bursa (11). It has an epiploic foramen opening into the main peritoneal cavity. Borders of the epiploic foramen: Ventrally: Portal vein Dorsally: Vena Cava Caudalis Caudally: Hepatic artery Cranially: Liver GREATER OMENTUM - the superficial leaf is visible. CRANIAL LIVER STOMACH SPLEEN VENTRAL ABDOMINAL WALL - CAUDAL REFLECTED  Greater omentum LEFT HAND Left fingers are placed inside the omental bursa - between the superficial leaf and the deep leaf of the greater omentum. The deep leaf is on the right palm. RIGHT HAND CRANIAL CAUDAL Hepatic a. EPIPLOIC FORAMEN EPIPLOIC FORAMEN LEFT LATERAL DECUBITUS – WE SEE THE RIGHT SIDE Portal v. Liver Borders of the epiploic foramen: Ventrally: Portal vein Dorsally: Vena Cava Caudalis Caudally: Hepatic artery Cranially: Liver IT ROOT OF THE MESENTERY Mesentery bunched around the origin of the cranial mesenteric artery Near L2  FALCIFORM LIGAMENT – filled with fat FALCIFORM LIGAMENT  CRANIAL CAUDAL LEFT MEDIAL LOBE FALCIFORM LIGAMENT FALCIFORM – filled with fat LIGAMENT this is going tobe in the and fissure it is go ula dad tohe blood with te now FALCIFORM LIGAMENT – attached to the QUADRATE LOBE FISSURE FOR THE ROUND LIGAMENT OF for THE LIVER diaphragm m.  LESSER OMENTUM – covering the papillary process of the caudate lobe of the liver CRANIAL SPLEEN CAUDAL STOMACH LIVER LESSER OMENTUM PANCREAS PAPILLARY PROCESS OF THE DUODENUM CAUDATE LOBE OF THE LIVER  Abdominal Contents: Digestive System Gastrointestinal tract – Stomach – Small intestine: duodenum, jejunum, ileum – Large intestine: cecum, ascending colon, transverse colon, descending colon Accessory organs of digestion – Liver – Gallbladder – Pancreas Abdominal Contents: Immune, Endocrine, Urinary, and Reproductive Systems Immune organs Reproductive organs – Spleen – Ovaries Endocrine organs – Uterus *The reproductive structures will be – Adrenal glands studied in detail in Anatomy II along with the pelvic viscera. – Pancreas Urinary organs – Kidneys – Ureters – Urinary bladder Gastrointestinal Tract 1 - 5 duodenum 1 cranial part 2 cranial flexure 3 descending duodenum 4 caudal duodenal flexure 5 ascending A stomach duodenum B duodenum 6 duodenojejunal C jejunum flexure D ileum 7 Ileocolic orifice E cecum F ascending colon G transverse colon H descending colon J rectum  Stomach side Largest dilation of the ight alimentary canal Musculoglandular Less Stores and partly mixes food – Adds enzymes, mucus, HCl V Lies largely in a transverse plane, more to the left a www.ef  It Left d.EE 2  Regions of the Stomach Pyloricregion Curvatures E 7 Cardia Fundus Body e yeah Pyloric region o Pyloric Antrum EE.IR fuI F.IN o Pyloric Canal o Sphincter (pylorus) Liver and stomach regions Cardiac region Fits Papillary process of caudate lobe Fundus Cranial duodenal flexure I Pyloric region of stomach body Descending duodenum Greater omentum attaches along greater curvature of Courtesy of Drs Ray Wilhite, Dan Hillmann and Joe Rowe stomach  SPLEEN STOMACH GASTRIC FOLDS (rugae) Gastrosplenic ligament (greater omentum)  Topography of the Stomach In this case, the stomach is almost empty. Viewed from the Left Viewed from the Right Note position of the fundus of the stomach. The stomach, when empty, does Pylorus and descending not contact the abdominal wall and found duodenum on right side. within the rib cage. topgtyif pgfsf plan Topography of the Stomach In this case, the stomach is moderately full. Viewed from the Left Viewed from the Right  Topography of the Stomach In this case, the stomach is greatly distended. Viewed from the Left Viewed from the Right The fully distended stomach may extend almost to the umbilicus (or beyond). This will push the intestinal mass dorsally and caudally. The liver will be pushed to the right and, due to the gastrosplenic ligament, the spleen follows the expansion of the stomach. Intestines Commences at the pylorus and continues to the anus Divided into the small intestine and the large intestine Duodenum Initial portion of the small intestine Short and closely attached to the abdominal roof by mesoduodenum Lies along the right body wall Cranial duodenal flexure Descending duodenum R side Caudal duodenal flexure Ascending duodenum Duodenojejunal flexure whenthe jejunalbegins  is taking away Thejejn Duodenocolic fold deanum Asach wton Descend  CRANIAL ASCENDING DUODENUM PANCREAS STOMACH DESCENDING DUODENUM LEFT RIGHT DESCENDING COLON CAUDAL DUODENAL DUODENOCOLIC FLEXURE FOLD CAUDAL  Jejunum and ileum Lies on the abdominal floor Multiple coils that occupy the ventral aspect of the abdomen Suspended by the a mesojejunum and mesoileum  The ileum opens into large intestine Note: There is no ileocecal Cecum- blind-ended orifice in the dog! pouch Arises at the junction of the ileum and colon Colon (opened) Ileocolic orifice 0 Cecum Ileum (opened) The cecum opens into the ascending colon via the cecocolic orifice. The main function of the large intestine is dehydration. Cecocolic orifice Colon (opened) Ileocolic orifice Result colon Cecum Ileum (opened)  The canine colon has three regions: Ascending (9)Rightside Transverse (10) - travels right to left Descending (11) Leftside – longest – follows the left flank 0 – terminates at the pelvic inlet as the rectum look hm AMFlexure for  CRANIAL be Ascending colon Transvers colon Mesocolon Cecum I Descending colon Ileum Duodenum Duodenocolic fold Jejunal mass CAUDAL Mesocolon he won suspends  Liver Cranial abdomen Largest gland Exocrine - produces bile; stored in gall bladder Endocrine – substances released to metabolize fat, carbohydrates and protein Diaphragmatic aspect – dog in dorsal recumbency, cranial to caudal view  Lohes The liver has 6 (six) lobes 6 oo Left lateral Left medial DO Quadrate Right medial Right lateral Coronyligant Caudate 0 – Caudate process – Papillary process Holds heir 800 Right triangular ligament - right crus of the diaphragm m. (above the right central tendinous part) and the right lateral lobe Left triangular ligament – left crus of the diaphragm m. and the left lateral lobe Diaphragmatic aspect – dog in dorsal recumbency, cranial to caudal view  Left triangular CAUDAL ligament DIAPHRAGM CRANIAL MUSCLE LIVER Left triangular ligament  Porta of the liver (yellow circle): between the caudate and papillary processes of the caudate lobe, hepatic vessels/nerves and ducts Papillary process: nestles in lesser curvature of stomach Cranial pole of right kidney sits in the renal impression of the caudate lobe Gallbladder located between right medial and quadrate lobes. related to is Liner asgallblade Right Left side right 9 Visceral surface – You are looking 53 cranially and dog is in dorsal recumbency. Liver Lobes Duodenum and pancreas reflected to the left side Left lateral Left medial quadrate Right medial Caudal vena cava Caudate process of caudate lobe Right Right lateral kidney < < cranial Caudal > Courtesy of Drs Ray Wilhite, Dan Hillmann and Joe Rowe  The gallbladder stores and concentrates bile Cystic duct Bile duct- – Union of hepatic and cystic ducts – Opens at the major duodenal papilla  CRANIAL LIVER LIVER (visceral aspect) (diaphragmatic aspect) GALLBLADDER BILE DUCT Kasady Major duodenal papilla (bile and DUODENUM (opened) CAUDAL pancreatic ducts opening)  Gallbladder = GB And various ducts associated with gallbladder < caudal Cranial > Right medial lobe Right lateral Quadrate lobe of liver GB lobe Caudate process of the caudate lobe 1 2 2 Left lateral lobe of the liver 3 57 1=cystic duct 2=hepatic ducts 3=bile duct (common bile duct Courtesy of Drs Ray Wilhite, Dan Hillmann and Joe Rowe  Pancreas Exocrine – enzymes to metabolize protein, carbohydrates and fats; empty into 8ʰ fig duodenum tests Endocrine- islets cells: produce insulin, glucagon and gastrin 0 Right lobe Body Left lobe  CRANIAL Body of the Left lobe of pancreas the pancreas Stomach Right lobe of the pancreas Duodenum CAUDAL  I alongshed cunkabsent  Spleen Left cranial part of abdomen Gastrosplenic ligament- hilus to greater curvature of the stomach RedSeretse and white pulp Stores and concentrates erythrocytes, filters blood (producing bilirubin), produces many lymphocytes  Medical imaging FIG. 14.11 (A) Lateral and (B) Ventrodorsal radiographic view of descending duodenum; 3, spleen; 4, os penis; 5, cecum; 6, fundus of stomach; 7, left kidney; 8, bladder; L, left; R, right. Dyce, Sack, and Wensing's Textbook of Veterinary Anatomy  Medical imaging 000 FIG. 14.15 (A) Lateral and (B) ventrodorsal radiographic views of the canine abdomen after administration of a barium suspension. 1, Stomach; 2, pyloric part; 3, descending duodenum; 4, caudal flexure of duodenum; 5, jejunum; L, left; R, right. Dyce, Sack, and Wensing's Textbook of Veterinary Anatomy  Medical imaging 0 FIG. 14.17 (A) Lateral and (B) ventrodorsal radiographic views of the feline abdomen after administration of a barium suspension. -filled falciform ligament elevating the liver; 2, gas 3, descending duodenum—the striking “string-of-pearls” appearance (characteristic of cats) is due to segmental peristalsis; 4, jejunum; 5, ascending colon; 6, transverse colon; 7, (superimposed); L, left; R, right. Dyce, Sack, and Wensing's Textbook of Veterinary Anatomy  Medical imaging father FIG. 14.19 Ventrodorsal radiographic view of the canine abdomen after administration of a barium suspension. 1, Residue of colon; 8, rectum; L, left; R, right. Dyce, Sack, and Wensing's Textbook of Veterinary Anatomy  There are three unpaired branches of the Vascularization abdominal aorta. Celiac a. 1. Hepatic 2. Splenic 3. Left gastric Cranial mesenteric a. 1. Common trunk: Ileocolic, right colic, middle colic 2. Caudal pancreaticoduodenal 3. Jejunal 4. Ileal Caudal mesenteric a. 1. Left colic 2. Cranial rectal Blood Supply to Stomach  Descending aorta Cranial mesenteric artery Adrenal gland Celiac artery Hepatic artery Left gastric artery Splenic artery spleen Courtesy of Drs Ray Wilhite, Dan Hillmann and Joe Rowe Blood Supply to Stomach All three chief branches of the celiac artery – Hepatic Right gastric and gastroepiploic arteries – Splenic Left gastroepiploic artery Short gastric branches – Left gastric Blood supply to the small intestine , mesenteric ileal b. 4. Ileal The duodenum is supplied by the cranial and caudal pancreaticoduodenal aa.  Jejunum is supplied by jejunal arteries/branches Ileum is supplied by mesenteric ileal artery (out of the ileocolic a.), ileal arteries (out of the cranial mesenteric a.) and antimesenteric ileal artery (out of the cecal a. which is out of the ileocolic a.) Blood supply to the large intestine , Common trunk Blood to the large intestine is via the Cecum - cecal aa. cranial and caudal mesenteric arteries Ascending colon - colic br. of ileocolic a. and right colic a. Transverse colon - middle colic a. and right colic a. Descending colon - left colic a. and middle colic a. Cranial part of rectum - cranial rectal a.  CRANIAL Ascending colon Transvers colon Right colic a. Descending colon Cecum Middle colic a. Ileocolic a. Common trunk CAUDAL  The liver is supplied by the hepatic artery, a branch of the celiac artery. The pancreas: supplied by cranial and caudal pancreaticoduodenal aa. + The splenic artery that gives branches for the left lobe of the pancreas. Left lobe  The spleen is supplied by the splenic a. Veins satellite to paired arteries will drain into the caudal vena cava. Veins that are satellite to unpaired arteries will drain into the hepatic portal vein. Key: Portal vein – lateral view 1 caudal vena cava 21 hepatic vv. 38 portal vein 39 gastroduodenal v. 40 splenic v. 41 caudal mesenteric v. 42 cranial mesenteric v. 43 jejunal vv. 80 The hepatic portal vein is formed from the following tributaries: the gastroduodenal vein, the splenic vein, the cranial mesenteric vein and the caudal mesenteric vein.  Canine Urinary System Dog 2 kidneys – filter plasma (6 and 6’) Lumbar region Hilus - indentation on the medial border that defines a space where the renal vessels and nerves and the ureter communicate with the organ Cat Ureters (11) Urinary bladder (14) FIG. 14.29 Urogram of a dog. 1, Gas in stomach; 2 kidneys; 3, ureters; 4, bladder; L, left; R, right. Dyce, Sack, and Wensing's Textbook of Veterinary Anatomy  Internal Features of the Kidney Identify renal cortex, medulla, hilus, sinus and pelvis. Connect to histology: Review the structures found in the cortex and the medulla of the kidney (Histology!) Hilus (yellow arrows) is medially oriented Cortex Medulla Renal pelvis Renal sinus https://static1.squarespace.com/static/56ccbe1727d4bd75712d3bb1/56ccf3 f82fe13126751b3925/587c375f893fc04ee2d25c65/1489268922601/CanineKi dney_Xsection.jpg Evans, Howard E.: Guide to the Dissection of the Dog, 7th Edition. W.B. Saunders Company. Fig. 4-23: Details of the canine kidney. The kidneys are retroperitoneal because they are covered only on their ventral surface by peritoneum. Kidney (ventral surface) In some dogs, usually large breed, the left kidney is pendulous, or floating. This is the Kidney (dorsal surface) normal condition in the cat.  Kidneys are supplied by the paired renal arteries. Ovarian (female)/ Testicular (male) vein (paired) Right ovarian/testicular vein drains into the caudal vena cava Left ovarian/testicular vein drains into the left renal vein  Adrenal glands Paired Lie against the roof of the abdomen Produce several hormones - note the interaction with the sympathetic system Reproductive organs Ovary Uterine horn Responsible for recognizing the ovaries and the uterine horns. There are several lymph nodes affiliated with the abdomen and abdominal viscera. Note: You do not have to look for all of these!! You should observe the jejunal lymph nodes. Lymph nodes 3. Hepatic 4. Splenic 5. Gastric 6. Pancreaticoduodenal 7. Jejunal 8. Right colic 9. Middle colic 10. Left colic Jejunum Ultimately, lymphatic vessels of the abdomen will drain into the cisterna chyli (#12 left and #5 right) which is continued by the thoracic duct. Dyce, K.M., W.O. Sack, C.J.G. Wensing. Textbook of Veterinary89 Anatomy, 4th Edition. W.B. Saunders Company, 2010.  Sympathetic vs. Parasympathetic Supply to the Gut Both PSNS and SNS to organs to maintain homeostasis The sympathetic chain continues from the thorax into the abdomen Sympathetic innervation: sympathetic chain splanchnic nerves (mostly pre- ganglionic) celiacomesenteric (pre- vertebral) ganglia and caudal mesenteric ganglia (where synapse will occur) – Post-ganglionic SNS leave ganglia to the viscera Cunningham, James G.. Textbook of Veterinary Physiology, 4th Edition. W.B. Saunders Company, 2007, 303. Parasympathetic innervation: Dorsal and Ventral vagal nerve trunks - Ventral trunk supplies the liver, stomach and pylorus; - Dorsal vagal trunk supplies the stomach, including pylorus before giving a celiac branch that contributes to the formation of the celiacomesenteric plexus. Parasympathetic axons follow the terminal branching of the respective blood vessels to the intestines at least as far caudally as the left colic flexure. All of these parasympathetic preganglionic axons will synapse with a second neuron within the wall of the organ where they terminate. Pelvic nerves from sacral spinal nerves - Pelvic nerves supply the gut distal to the left colic flexure (descending colon, rectum) and pelvic organs (urogenital organs).  5. Vagal plexus along lesser curvature 6. Ventral vagal trunk 7. Dorsal vagal trunk 8. Celiac nerve branch 22. Celiacomesenteric ganglion and plexus Clinically Oriented Anatomy of the Dog and Cat (2nd Edition), M.S.A Kumar.  SNS in the abdomen Pre-vertebral ganglia contain post-SNS cell bodies (where pre-synaptic fibers synapses) Splanchnic nerves (major splanchnic (11), minor splanchnic (14) and lumbar nerves (17)) convey mostly pre-ganglionic fibers to pre-vertebral ganglia Pre-vertebral ganglia are located adjacent to major arterial branches of the abdominal aorta: – The celiac ganglion* is near the celiac artery – The cranial mesenteric ganglion* is near the cranial mesenteric artery – The caudal mesenteric ganglion is near the caudal *Due to their close affiliation, the celiac mesenteric artery ganglion and the cranial mesenteric ganglion are often “grouped together” and referenced as the celiacomesenteric ganglion and plexus.  Splanchnic nerves distribute pre-ganglionic SNS axons to pre-vertebral ganglia. 5 1 2 6 3’ 3 4 1. Celiac ganglion 3. Major splanchnic n. 5. Dorsal vagal trunk 2. Cranial mesenteric 3’. Minor splanchnic n. (celiac br. to plexus) ganglion 4. Sympathetic chain of ganglia 6. Celiac a. Don’t forget about the role of the adrenal gland in the “fight or flight” (SNS) response! 3’ 3  Hypogastric nn. from caudal mesenteric ganglia carry post-ganglionic sympathetics to pelvic plexus 2 4 1 3 5 5 1. Caudal mesenteric ganglion 4. Hypogastric nn. (left and right) 2. Mesenteric plexus 5. Lumbar splanchnic n. 3. Caudal mesenteric a.  Minor splanchnic n. Major splanchnic n. Adrenal gland Sympathetic trunk/chain Celiac artery Cranial mesenteric artery Celiacomesenteric ganglia and plexus CRANIAL CAUDAL  Ventral branches of Lumbar splanchnic n. the lumbar nn. Celiacomesenteric ganglia and plexus AORTA Caudal mesenteric ganglia and plexus CRANIAL CAUDAL  Lumbar splanchnic n. Caudal mesenteric artery Right and left hypogastric nn. Caudal mesenteric ganglia and plexus 100