Bovine

Question 1

What cells line the rumen, reticulum, and omasum?

Answer 1

stratified squamous epithelium

Question 2

What is the capacity of the rumen?

Answer 2

102-148 liters

Question 3

What vessel supplies the omasum?

Answer 3

left gastric artery (a branch off of the celiac artery)

Question 4

The rumen is innervated mainly by?

Answer 4

the dorsal vagal trunk

Question 5

The atrium of the rumen and the other three compartments are innervated by?

Answer 5

The dorsal and ventral trunks of the vagus nn.

Question 6

What abdominal organs does the dorsal vagal trunk innervate?

Answer 6

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)

Question 7

What abdominal organs does the ventral vagal trunk innervate?

Answer 7

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.

Question 8

Name the layers of the esophagus from outer to inner.

Answer 8

adventitial layer (tunica adventitia –> becomes the tunica serosa in the thoracic esophagus), muscular layers (tunica muscularis), submucosa (tela submucosa), and mucosal layer (tunica mucosa)

Question 9

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.

Answer 9

True

Question 10

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.

Answer 10

True

Question 11

What cells line the lumen of the esophagus?

Answer 11

stratified squamous epithelium

Question 12

Which arteries supply the esophagus?

Answer 12

Blood is supplied from the cranial thyroid, common carotid, bronchoesophageal, and reticular arteries

Question 13

What innervates the esophagus?

Answer 13

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.

Question 14

What nerve(s) innervates the rumen, caudal aspect of the reticulum, omasum, and visceral surface of the abomasum?

Answer 14

the dorsal vagal trunk

Question 15

What nerve(s) supplies the reticulum, parietal side of the reticuloomasal junction, omasum, and abomasum?

Answer 15

the ventral vagal trunk

Question 16

What are causes of a left-sided tympanic resonance (ping)?

Answer 16

rumen tympany, rumen collapse or void, left displacement of the abomasum, and pneumoperitoneum

Question 17

What are causes of a right-sided tympanic resonance (ping)?

Answer 17

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

Question 18

What are the end products of microbial fermentation in the rumen?

Answer 18

volatile fatty acids (mainly acetate, propionate, and butyrate), ammonia, and gases (CO2 and methane)

Question 19

Where in the GI tract are volatile fatty acids absorbed?

Answer 19

They are absorbed through the walls of the rumen

Question 20

Highly fibrous, low energy feed such as pasture hay lead to microbial population which produce ____ ratios of acetate to propionate.

Answer 20

high ratios; Acetate is an end product from the fermentation of fiber.

Question 21

T/F: Feeds high in rapidly fermentable carbohydrates such as cereal grains lead to population of bacteria which produce relatively more propionate and butyrate than acetate

Answer 21

True; propionate is an end-product of fermentation of starch and sugars; acetate of fiber