Stomach- Gross Anatomy

Question 1

identify and describe the anatomic structures of the dog stomach (6)

Answer 1

food travels from esophagus, through lower esophageal/cardiac sphincter to the fundus and then through the body (most ventral region) through the pyloric portion which narrows into a funnel/pyloric canal and through the phyloric sphincter into the duodenum

Question 2

identify and describe the anatomic structures of the equine stomach (7)

Answer 2

food travels from the esophagus through the super strong cardiac sphincter into the fundus (nonglandular portion), past the margo plicatus which separates from nonglandular from the glandular stomach into the glandular body through the pyloric gland area (which narrows even more than the dog) and through the pyloric sphincter into the duodenum

Question 3

what is clinically significant about the margo plicatus?

Answer 3

bot fly larvae love to hang out there because they are protected from the HCl of the glandular stomach and can mature into pupa there

Question 4

identify and describe the anatomic structures of the cow

Answer 4

reticulum, rumen, omasum, abomasum

Question 5

describe the sacs/divisions of the rumen

Answer 5

the rumen is subdivided by thickenings of the rumen wall; these thickenings are folds or grooves exteriorly with a corresponding pillar on the interior

the dorsal sac and ventral sac are divided by the longitudinal groove, and coronary grooves in both the dorsal and ventral sac create the caudodorsal blind sac and the caudoventral blind sac, which are separated by a caudal groove; the dorsal sac has a cranial compartment called the cranial sac/atrium, which is separated from the ventral sac by the cranial groove; and the rumen is separated from the rumen by the rumenoreticular fold

Question 6

compare the anatomy of the stomach of the dog, horse, and cow

Answer 6

the only major difference between the horse and dog is that the horse has an enlarged nonglandular region compared to the dog at the fundus, forming the saccus caecus; in the cow the saccus caecus is enlarged by a shit ton and given compartments to be called the rumen, and the stomach is cows is further divided into reticulum, omasum, and abomasum plus the rumen

Question 7

describe blood supply to the stomach in the dog, horse, and cow

Answer 7

3 major branches of abdominal aorta
1st branch, most cranial:
celiac artery: supplies spleen (splenic), stomach (left and right gastric), liver (hepatic)

2nd branch: cranial mesenteric: has the most branches, supplies most of intestines, jejunal, right colic, middle colic, ileocolic, colic branch of ileocolic

3rd branch: caudal mesenteric, has cranial rectal that supplies distal LI toward rectal region

Question 8

describe the innervation of the GI tract in he dog, horse, and cow

Answer 8

sympathetic:
1. combined celiac and cranial mesenteric ganglia; nerves branch from these and located around celiac and cranial mesenteric arteries
2. left and right caudal mesenteric ganglia

parasympathetic:
nodose ganglion at the base of the skull is the source for all parasympathetic innervation, nerves branch from here and run all the way to abdominal cavity