GI tract motility

Question 1

Gastrocolic Reflex

Answer 1

• presence of food in the stomach tells the colon to make way, then the colon will take food from previous meal and move it down the tract to be removed as waste (defecation)

Question 2

Gut Motility

Answer 2

• Peristalsis: main sort of utility (muscles of tunica muscularis)
• Mechanical Digestion
• Mixing

Question 3

Lamina muscularis

Answer 3

• Helps squeeze glands, not actually around glands

Question 4

Small Intestine Motility

Answer 4

• Peristalsis: arrangement of longitudinal and circular muscle
• Segmental: mixing back and forth uses rythmic contractions of circular muscle

-Segmentation: back and forth mixing of food in the stomach, play on peristalsis, milking the contents (milking backwards and forwards), keeps food in gut longer to allow digestion, and also a mechanical action of breaking food into particles and causing further secretions. Muscle causing movement back and forth

Question 5

Large Intestine Motility

Answer 5

• Peristalsis - including mass movements
• Haustration- similar to segmentation, but with the formation
• of sacs which store and propel contents
• small pouches of colon caused by sacculation
• Sacs get formed in large intestine, longitudinal muscle that runs along length of large intestine become bounds and they contract and it shortens the length of the intestine and forms sacs rather than being uniformal. Slowing transit time (important in hindgut fermenters in horses which allows time for fermentation) and allows for more digestion

Question 6

Migrating motor complex

Answer 6

• Digestive Phase peristaltic contractions passover short segments of the intestine
• Interdigestive Phase peristaltic contractions pass over large segments of the intestine
• The migrating motor complex is a distinct pattern of electromechanical activity observed in gastrointestinal smooth muscle during the periods between meals. It is thought to serve a “housekeeping” role and sweep residual undigested material through the digestive tube
• regulates MASS MOVEMENT
• cells have cross talk and will coordinate depolarizations that will help sweep out undigested material
• cant have gut flora increasing exponentially–> control bacterial population

Question 7

Recto-sphinteric reflex

Answer 7

• Rectum is full, sphincter relaxes
• Contraction of Diaphragm and Abdominal Musculature
• Need these all together to have a nice ol’ poo