GIT anatomy

Question 1

Name some monogastric animals

Answer 1

Cats, dogs, pigs, humans, chickens

Question 2

Name some ruminants

Answer 2

cattle, sheep, giraffe, goats

Question 3

Name some hind gut fermenters

Answer 3

horses, rabbits, elephant, ostrich

Question 4

What are the 4 GIT functions?

Answer 4

1. motility, 2. digestion, 3. secretion, 4. absorption

Question 5

Characteristics of motility?

Answer 5

Mixing ingested material with secretions
Peristalsis
Rate of movement varies bwn feed/spp

Question 6

Characteristics of digestion?

Answer 6

Breakdown into smaller molecules - mechanical/enzymatic

Aided by secretions

Question 7

Characteristics of secretion?

Answer 7

Release of useful substances in GIT lumen

Secretions: enzymes, buffers, bile, lubrication, solvent

Question 8

Characteristics of absorption?

Answer 8

nutrient uptake & use
uses specialised cells lining GIT lumen
passive or active

Question 9

Pharynx?

Answer 9

Passage for food to oesophagus & air to larynx

Lined by mucous membrane

Question 10

Oesophagus?

Answer 10

Continuation of pharynx

Passage of food

Question 11

Regions of pharynx?

Answer 11

naso-, oro-, laryngo-pharynx

Question 12

Difference in bird oesophagus?

Answer 12

Contains crop (in prey birds) for temp food storage

Question 13

Monogastric stomach anatomy?

Answer 13

cardiac sphincter, rugae, stomach, pyloric sphincter

Question 14

How does monogastric digest?

Answer 14

HCl secretions - parietal cells
pepsinogen - chief cells
some bacterial activity in oesophagus
Collectively: Glandular Digestion

Question 15

What are the 3 stomach glands & their secretions?

Answer 15

Cardiac (mucus), pyloric (mucus & pepsinogen), fundic (mucus, HCl, pepsinogen)

Question 16

Two stomachs in birds & functions?

Answer 16

proventriculus (adds enzymes) & ventriculus/gizzard (grinding, mixing, contains grit)

Question 17

Ruminent stomachs?

Answer 17

rumen, reticulum, omasum (forestomach), abomasum (stomach)

Question 18

Rumen & reticulum characteristics?

Answer 18

Fermentation, chew cud (ruminate), microbes & water (alkaline pH), anaerobic

Question 19

Omasum characteristics?

Answer 19

Small hard round, filled with muscular laminae (grinds roughage to reduce size, squeezes fluid out, absorbs H2O & FA’s)

Question 20

Abomasum characteristics?

Answer 20

true stomach, first glandular part of GIT, same function as monogastric stomach

Question 21

Small intestine characteristics?

Answer 21

Long, narrow, digesta moves thru quickly, mobile (attached by mesentery) Mucous layer covered in villi providing enormous surface area

Question 22

3 small intestine segments?

Answer 22

Duodenum (near pancreatic & bile ducts), jejunum (longest part), ileum

Question 23

3 large intestine segments?

Answer 23

Caecum, colon, rectum

Question 24

Caecum characteristics?

Answer 24

Large comma-shaped sac with ‘blind’ end. Appendix is on end in some species.

Question 25

Large colon characteristics?

Answer 25

Largest capacity in GIT. Folds into 4 regions (left, right, dorsal, ventral)

Question 26

Small colon characteristics?

Answer 26

Similar length to large colon, but smaller volume. narrow and more coiled. More free to move (can result in twisted gut)

Question 27

Differences in GIT volumes (stomach/small intestine/large intestine) hind-gut fermenters vs ruminants?

Answer 27

Horse: Stomach - 10L, SI - 30L, LI - 60L Cow: Stomach - 70L, SI - 20L, LI - 10L

Question 28

2 types of rabbit faeces?

Answer 28

1. hard round dark 2. caecotrope - softer & larger (essential for digestion of cellulose to soluble nutrients)

Question 29

What is coprophagy?

Answer 29

Ingestion of faeces

Question 30

What are the 4 accessory digestive organs?

Answer 30

Salivary glands, liver, pancreas, associated SI glands

Question 31

Salivary gland characteristics?

Answer 31

Major glands: parotid, mandibular, sublingual | Minor glands: labial, buccal, lingual, palatine

Question 32

Liver secretion characteristics?

Answer 32

Processing of absorbed nutrients, energy storage, bile secretion, breakdown of exhausted RBC's.

Question 33

Bile secretion pathway?

Answer 33

Hepatic ducts + common cystic duct -> common bile duct -> duodenum (Horse has no gall bladder so secretes continuously)

Question 34

Pancreas secretion characteristics?

Answer 34

Near roof of abdomen (adjacent to duodenum) 2 functions: 1. exocrine (Na bicarb & digestive enzymes via ducts) 2. endocrine (secretes into blood without ducts (insulin, glucagon, somatostatin)

Question 35

Associated SI glands characteristics?

Answer 35

Brunner's glands (duodenum - enzymes & mucus), Crypts of Lieberkuhn (between villi on SI - digestive enzymes), Peyer's patches (submucosa of intestines (esp ileum) - immune function)