Large Animal Abdomen Flashcards
What are the main nerves that innervate the abdominal wall?
- ventral branch of T13
- iliohypogastric nerve (ventral branch of L1)
- ilioinguinal nerve (ventral branch of L2/L3)
- lateral femoral cutaneous nerve (ventral branch of L3/L4)
What are the attachments of the greater omentum in the ox?
- greater curvature of abomasum
- reticulum
- mesoduodenum of descending duodenum
- left longitudinal groove of rumen (superficial leaf)
- right longitudinal groove of rumen (deep leaf)
What is the supraomental recess?
the region that contains the intestines dorsal to the sling created by the greater omental leaves
What are the major features of the Rumen?
- largest compartment
- fills entire left side of abdomen
- papillae varying in size and density
What are the grooves and corresponding pillars of the Rumen?
- left and right longitudinal grooves/pillars: divide rumen into dorsal and ventral sacs
- dorsal and ventral coronary grooves/pillars: divide caudal aspect into caudoventral and caudodorsal blind sacs
- right accessory groove/pillar: extends from cranial to caudal groove/pillar
- left accessory groove/pillar: extends dorsally from cranial groove/pillar
What is the Intraruminal orifice?
- region bounded by right and left longitudinal pillars, and cranial and caudal pillars
- communication between dorsal and ventral sacs
What is the Insula ruminis?
- space between the right accessory pillar and right longitudinal pillar
What is the recessus ruminis?
most cranial compartment of the ventral sac of the rumen
- located ventral and caudal to the cranial pillar
What is the function of the Rumen?
digestion of complex carbohydrates, and absorption of the resultant VFAs
What vessels supply the Rumen?
- right ruminal artery (branch of splenic artery)
- left ruminal artery
What innervates the ruminant stomach?
the dorsal vagal trunk
- ventral for abomasum
What are the major features of the Reticulum?
- cranial position close to liver and diaphragm
- honey comb-like cells
- reticular groove with left and right lips
What is traumatic reticulitis or “hardware disease”?
- when a piece of metal is lodged in the reticulum
- if sharp, it can pierce through the reticulum and diaphragm, and into the pericardium or heart
What are the functions of the Reticulum?
- mechanical digestion, filtration of particulate matter, movement, and absorption
- holds course material in, or sends back to rumen
What are the main features of the Omasum?
- spherical shape
- parallel folds (laminae) with papillae and interlaminar recesses
What are the functions of the Omasum?
- mechanical digestion and absorption
- biphasic contraction to bring ingesta in, expel fluids, and send solids to abomasum
What are the main features of the Abomasum?
- glandular stomach
- spiral folds that do not disappear with distention
- lined with glandular mucosa
What is the function of the Abomasum?
- chemical digestion via release of enzymes and chemicals from gastric glands
What is the Torus pyloricus?`
a round protuberance in the pylorus that augments the pyloric sphincter
What vessels supply the lesser curvature of the Abomasum?
right and left gastric arteries
What vessels supply the greater curvature of the Abomasum?
right and left gastroepiploic arteries
What is the Gastric groove?
- reticular groove + omasal groove + anomasal groove
- allows ingested material to bypass the forestomachs and go directly to abomasum
- unweaned calf drinking milk
- dehydration in adults
- use of ADH or copper sulfate in adults
What is the separation of the glandular and non-glandular regions in the horse stomach?
Margo plicatus
Describe the course of the ascending colon in the horse
- right ventral colon runs cranially, turns as ventral diaphragmatic flexure, and continues caudally as left ventral colon
- turns as pelvic flexure, and runs cranially as left dorsal colon, turns as dorsal diaphragmatic flexure, and runs caudally as right dorsal colon
What are the differences in the small intestine of the ox?
Jejunum: surrounds the spiral loop of the ascending colon
- lymph nodes appear as a solitary line running with the intestine
Ileum: connected to cecum via ileocecal fold
Describe the course of the ascending colon in the ox
- proximal loop (sigmoid shape)
- centripetal gyri (spiral inwards)
- central flexure
- centrifugal gyri (spiral outwards)
- distal loop (sigmoid shape)
What are the differences in the small intestine in the horse?
Duodenum: duodenocolic fold connects ascending duodenum and descending colon
Ileum: no antimesenteric ileal branch
- ileocecal fold attaches ileum to cecum
- opens to cecum via ileal orifice and papilla
Describe the location of the cecum in the horse
- base attached to dorsal body wall
- body projects into right ab. wall, and held in place by cecocolic fold
- apex extends cranially on ab. wall floor, between left and right ventral ascending colon
How many bands are present on the cecum and colon parts?
What are the bands called?
- Taenia coli
- cecum: 4
- ventral colon: 4
- pelvic flexure and LDC: 1
- dorsal diaphragmatic flexure and RDC: 3
- transverse and descending colon: 2
What vessels supply the ascending colon of the ox?
- colic branch of ileocolic a. supplies proximal loop and centripetal gyri
- right colic a. supplies centrifugal gyri and distal loop
What vessels supply the ascending colon of the horse?
- colic branch of ileocolic a. supplies ventral colon
- right colic a. supplies dorsal colon
What vessels supply the transverse colon in the ox and horse? Descending colon?
transverse: middle colic a.
descending: left colic a.
Where can the horse get intestinal entrapment?
- epiploic foramen: jejunum and ileum trapped within it
- nephrosplenic ligament: large colon trapped over this ligament which connects spleen and left kidney
What are main impaction sites in the horse?
- ventral colon turning as pelvic flexure
- right dorsal colon to transverse colon
Which viscera are commonly displaced in the horse?
- apex of cecum
- most of ascending colon, mainly pelvic flexure and left colon
