Canine GIT

Question 1

Describe the alimentary canal

Answer 1

Tube from lips to anus (we are essentially donuts) 🍩
Includes the mouth, pharynx, oesophagus, stomach, small and large intestine

Question 2

Tubular organs have a general structure of 4 layers. List these (inside to outer layers) and name what tissue they are made up of

Answer 2

1) Tunica mucosa (3 more layers)
2) Tunica submucosa - dense connective tissue
3) Tunica muscularis - smooth or skeletal muscle
4) Tunica serosa/adventitia - loose connective tissue

Question 3

What are the three layers of the tunica mucosa (layer closest to the lumen)

Answer 3

-Laminae epithelialis mucosa (surface epithelium)
-Lamina propria mucosa (layers of connective tissue)
-Lamina muscularis mucosae (thin layers of smooth muscle)

Question 4

What does the oesophagus connect?

Answer 4

Pharynx with the stomach

Question 5

For most of its length it is accompanied by the left 1)______ _____ artery and 2)______ and 3)______ ______ nerves

Answer 5

1) common carotid
2) vagosympathetic
3) recurrent laryngeal nerves

Question 6

What 3 anatomical subdivisions is the oesophagus split into?

Answer 6

Cervical, thoracic and abdominal

Question 7

What is the location of the stomach?

Answer 7

Left side of the cranial abdomen,

Question 8

Explain the segments of the stomach: cardia, fundus, body and pylorus

Answer 8

Caria - opening of oesophagus, prevents back flow
Fundus - blind expanded portion of the stomach, storage area for gas and food
Body - main middle part of the stomach, mechanical and chemical digestion
Pylorus - distal to the body, controls the flow of partially digested food into the small intestine

Question 9

The stomach has specific regions according to cell type: cardiac glands, fundic glands and pyloric glands. What are they collectively called? What do each secrete?

Answer 9

Gastric glands
Cardiac secretes mucus
Fundic produces and secretes HCl
Pyloric secretes mucus and the hormone gastrin

Question 10

Which type of epithelium lines the lumen in the stomach?

Answer 10

Simple columnar

Question 11

The entire gastric mucosa is densely pockmarked by ____

Answer 11

Innumerable tiny depressions = pits

Question 12

What type of cells are present in the pits of the stomach wall?

Answer 12

Mucous cells, Parietal and endocrine, chief (protein-secreting)

Question 13

Visceral surface

Answer 13

The side of the stomach in contact with the
remaining abdominal viscera-intestines;

Question 14

What is the name of the surface where the side of the stomach is in contact with the liver?

Answer 14

Parietal surface

Question 15

What is the peritoneum(incl. cell type)?

Answer 15

A thin serous membrane of mesothelial cells

Question 16

What is the connecting peritoneum?

Answer 16

Double-layered serosa connecting two peritoneum

Question 17

Explain what the omental bursa is

Answer 17

A cavity in the abdomen located behind the stomach and the lesser omentum

Question 18

Where do the lesser and greater omentum attach?

Answer 18

Lesser = lesser curvature of the stomach to the liver
Greater - greater curvature of the stomach to the left part of the colon, pancreas, and the dorsal body wall

Question 19

What is the epiploic foramen?

Answer 19

The omental bursa opening to the peritoneal cavity

Question 20

What are the three parts of the small intestine called?

Answer 20

Duodenum (pancreas and bile ducts empty into the intestines)
Jejunum
Ileum

Question 21

What is the mesentery? How is it named?

Answer 21

It is a double-layered fold of tissue that attaches to the abdominal wall
Named according to the organ they suspend eg mesoduodenum, mesocolon etc

Question 22

Describe the general structures found in the small intestine

Answer 22

Plicae circulares - deep circular folds
Villi (lined by columnar epithelial cells)
Microvilli
Crypts (of Lieberkühn) - contain goblet and neuroendocrine cells

Question 23

Which area of the small intestine has the longest villi and the highest number of goblet cells?

Answer 23

Duodenum

Question 24

List structures in the large intestine

Answer 24

Caecum
Colon (ascending, transverse, descending)
Rectum

Question 25

Describe the blood supply to the canine stomach

Answer 25

Comes from all three main branches of coeliac artery 1) Left gastric a. 2) Hepatic a. 3) Spelic a. The veins correspond to the arteries, and train to the PORTAL vein

Question 26

Describe the blood supply to the canine intestine

Answer 26

Cranial and caudal mesenteric arteries

Question 27

Describe the innervation of the canine stomach and intestines

Answer 27

Parasympathetic, sympathetic and enteric nervous system

Question 28

List features of the Enteric Nervous System

Answer 28

- Part of ANS - Involuntary - Mesh-like system of nerves - Composted of two plexus (submucosal/meisner and myenteric/auerbach)