Abdominal Viscera (Veterinary Anatomy)

Abdominal Viscera Alimentary Canal (esophagus, stomach, intestine) A. Esophagus — cervical, thoracic, abdominal regions (all striated in dog; proximal 2/3’s striated in cat ) B. Stomach: Sphincters: 1) Cardiac (at cardia) and 2) Pyloric (at pylorus) Region: a) Cardiac (surrounding cardia) b) Fundic (fundus = blind end) c) Body d) Pyloric (antrum & canal) also, lesser curvature — LESSER OMENTUM greater curvature — GREATER OMENTUM C. Small Intestine: 1) Duodenum — MESODUODENUM regions: a) Cranial flexure b) Descending duodenum c) Caudal flexure d) Ascending duodenum e) Duodenal-jejunal flexure 2) Jejunum — MESOJEJUNUM ----->MESENTERY 3) Ileum — MESOILEUM -----> MESENTERY antimesenteric vessel; ileocecal fold ileal (ileocolic) orifice D. Large Intestine: 1) Cecum (blind end; no appendix) cecocolic orifice; ileocecal fold 2) Colon — MESOCOLON Regions: a) Ascending colon b) Right colic flexure c) Transverse colon d) Left colic flexure e) Descending colon 3) Rectum — MESORECTUM 4) Anal canal (retroperitoneal) Anus = external opening Sphincters — a) Internal anal sphincter (smooth m.), b) External anal sphincter (striated m.);Liver Secretes bile salts which emulsify ingested fat; bile is tored in the gallbladder develops in ventral mesogastrium: (Diaphragm / LIGAMENTS / LIVER / LESSER OMENTUM / stomach) Six lobes: Rright lateral lobe Right medial lobe Gallbladder Quadrate lobe Left medial lobe Left lateral lobe Caudate lobe — Papillary process Caudate process PancreasPancreas — Secretes proteolytic enzymes into duodenum; also, endocrine secretions (insulin, etc.) Structure: left lobe + body + right lobe; located in GREATER OMENTUM & MESODUODENUM Ducts: Pancreatic duct (smaller) empties with bile duct —> major duodenal papilla. Accessory pancreatic duct (larger) empties —> minor duodenal papilla. Kidney: — removes waste products from blood (urine); — regulates fluid/salt balance (blood osmotic pressure) Topography — Right kidney is more cranial than the left; Cranial pole of right kidney is cupped by liver; Left kidney is more loosely attached; Feline kidneys are positioned more caudally. Surface features — cranial / caudal poles dorsal / ventral surfaces medial / lateral borders: medial border has a hilus (where vesselsand the ureter enter) that leads to aspace (renal sinus) where the renal pelvis is located. Kidney structureA fibrous capsule surrounds the kidney (capsular veins are prominent in the cat) renal cortex = superficial tissue that contains vascular glomeruli renal medulla = deep tissue (an outer part and a less vascular inner part can be distinguished) renal pyramid = the medulla between interlobar vessels (belonging to a renal lobe) renal papilla = the free tip of a renal pyramid (not present as such in carnivores) renal crest = median ridge produced by fusion of renal papillae in the carnivore Ureter (forms branches and calyces in multilobar kidneys) conveys urine from kidney to urinary bladder. renal pelvis = expanded proximal end of ureter ( located within renal sinus of unilobar kidney) pelvic recess = lateral expansion of renal pelvis between interlobar vessels. Spleen: Structure — develops in dorsal mesogastrium; — becomes enlarged when capsular & trabecular smooth muscle relax (e.g., under barbiturate anesthesia) Function — serves as a reservoir for blood cells (blood storage) — filters particles from blood, particularly over-aged erythrocytes.