Flashcards in Bovine Deck (21):
What cells line the rumen, reticulum, and omasum?
stratified squamous epithelium
What is the capacity of the rumen?
What vessel supplies the omasum?
left gastric artery (a branch off of the celiac artery)
The rumen is innervated mainly by?
the dorsal vagal trunk
The atrium of the rumen and the other three compartments are innervated by?
The dorsal and ventral trunks of the vagus nn.
What abdominal organs does the dorsal vagal trunk innervate?
Rumen, reticulum, omasum, abomasum (The dorsal vagal trunk supplies the right side of the atrium, the brr. to the celiac plexus, the dorsal ruminal brr., and the right ruminal br., which runs back in the right accessory groove, giving brr. to the dorsal and ventral sacs, and passing around in the caudal ruminal groove to the left side. A branch of the dorsal trunk is also given off to the cranial ruminal groove and left longitudinal groove and to the greater curvature of the abomasum. Branches of the dorsal trunk pass over the omasum and the visceral side of the lesser curvature of the abomasum, innervating the right lip of the reticular groove, the caudal (visceral) surface of the reticulum, both sides of the omasum, and the visceral surface of the abomasum to the pylorus)
What abdominal organs does the ventral vagal trunk innervate?
atrium of the rumen, reticulum, parietal surface of the omasum and abomasum, liver, duodenum, pylorus, (The ventral vagal trunk gives branches to the left side of the atrium, the diaphragmatic surface of the reticulum, and branches that run in the lesser omentum to the liver, cranial part of the duodenum, and pylorus. Branches of the ventral trunk innervate the left lip of the reticular groove, and continue across the parietal side of the neck of the omasum and run in the lesser omentum along the parietal surface of the base of the omasum and the lesser curvature of the abomasum to the pylorus, innervating the parietal surface of the omasum and abomasum.)
The esophagus does not have an abdominal portion in the ruminant, however the esophageal branches of the vagus nerve innervate the cranial half of the esophagus. The caudal half is innervated by esophageal branches off the recurrent laryngeal and vagal nerves.
Name the layers of the esophagus from outer to inner.
adventitial layer (tunica adventitia --> becomes the tunica serosa in the thoracic esophagus), muscular layers (tunica muscularis), submucosa (tela submucosa), and mucosal layer (tunica mucosa)
T/F: In ruminants, except at the cranial and caudal ends, the tunica muscularis comprises outer and inner spiral layers of striated muscle ﬁbers that run throughout the length of the esophagus. At the cranial and caudal ends, the inner muscle layer consists of circular ﬁbers, whereas the outer layer consists of longitudinal ﬁbers.
T/F: The outer layer of elliptical ﬁbers at the pharyngeal end of the esophagus is incomplete ventrally, where
it attaches to the cricoid cartilage. At this site, the overlapping pharyngeal and esophageal musculature forms a pharyngoesophageal sphincter.
What cells line the lumen of the esophagus?
stratiﬁed squamous epithelium
Which arteries supply the esophagus?
Blood is supplied from the cranial thyroid, common carotid, bronchoesophageal, and reticular arteries
What innervates the esophagus?
Esophageal branches of the vagus nerve innervate the cranial half of the esophagus. The caudal half is innervated by esophageal branches off the recurrent laryngeal and vagal nerves.
What nerve(s) innervates the rumen, caudal aspect of the reticulum, omasum, and visceral surface of the abomasum?
the dorsal vagal trunk
What nerve(s) supplies the reticulum, parietal side of the reticuloomasal junction, omasum, and abomasum?
the ventral vagal trunk
What are causes of a left-sided tympanic resonance (ping)?
rumen tympany, rumen collapse or void, left displacement of the abomasum, and pneumoperitoneum
What are causes of a right-sided tympanic resonance (ping)?
right-displaced abomasum (RDA), abomasal volvulus (RVA), cecal dilation and/or volvulus, distension of the proximal colon, pneumorectum, pneumoperitoneum, distension of small intestine, ventral sac of rumen, and physometra
What are the end products of microbial fermentation in the rumen?
volatile fatty acids (mainly acetate, propionate, and butyrate), ammonia, and gases (CO2 and methane)
Where in the GI tract are volatile fatty acids absorbed?
They are absorbed through the walls of the rumen
Highly fibrous, low energy feed such as pasture hay lead to microbial population which produce ____ ratios of acetate to propionate.
high ratios; Acetate is an end product from the fermentation of fiber.