Intestinal Motility

Question 1

Name the types of intestinal motility

Answer 1

Segmentation = short range
Peristaltic reflex = short range
Migrating motor complex = 90-120 min per cycle

Question 2

Describe function of peristaltic reflex

Answer 2

Propels bolus along entire length of intestine

Question 3

Describe segmentation

Answer 3

Contractional relaxation of circular smooth muscles = back-and-forth mixing movement

Segmentation occurs primarily in the small intestine, where it helps optimize nutrient absorption by maximizing contact between chyme and the absorptive surface.

Question 4

Describe migrating motor complex

Answer 4

Interdigestive period = during fasting periods, between meals, and during sleep

Facilitate housekeeping functions, including the removal of debris and undigested material from the GI tract
Prevent migration of colonic bacteiral into distal ileum

Question 5

What is the function of small intestine motility?

Answer 5

To process and absorb nutrients

Question 6

What are the organized motor activities needed in small intestine?

Answer 6

Mix chyme with digestive juices and bile = to facilitate digstion and absorption
Propelling chyme in a caudad direction
Bringing chyme into contact with microvilli

Question 7

What is the transit time in the small intestine?

Answer 7

2-4 hours from one end to the other
Last part of one meal leaves ileum as next meal enters stomach

Question 8

What happens during fasting?

Answer 8

Mixing and propulsion still occur = cleansing the small intestine

Question 9

What regualtes intestinal motility?

Answer 9

Gastrin
Intestino-intestinal reflex
Ileogastric reflex
Gastroileal reflex

Question 10

What is the role of gastring in regulation of intestinal motility?

Answer 10

Stimulate motility in ileum
Promote relaxation ofileocecal sphincter

Question 11

What is the intestino-intestinal reflex?

Answer 11

Neural reflex that occurs within the intestines and helps regulate intestinal motility and function

When these sensory receptors are stimulated, they generate electrical signals that are transmitted along the enteric nervous system (ENS)

Question 12

What happens when there is distension or injury to any portion of small intseines?

Answer 12

It inhibits motility in the rest of the small intestine to allow time for the distended segment to empty and return to its normal state

This is the intestino-intestinal reflex

Question 13

What is the ileogastric reflex?

Answer 13

Involves the coordination between the ileum (the final section of the small intestine) and the stomach

It plays a role in regulating gastric motility and secretion based on the contents and activity of the ileum

Question 14

What happens when there is distension of the ileum?

Answer 14

Inhibits gastric motilty

If the ileum detects the presence of a large amount of undigested food or a high level of distension, the ileogastric reflex may inhibit gastric contractions and secretion to slow down gastric emptying and allow more time for digestion and absorption in the small intestine. Conversely, if the ileum signals that its contents have been processed and absorbed, the reflex may stimulate gastric contractions and secretion to facilitate the movement of food into the small intestine.

Question 15

What is the gastroileal reflex?

Answer 15

This reflex plays a role in regulating the emptying of the ileum and the movement of chyme (partially digested food) from the small intestine into the large intestine

Chyme in stomach triggers increased motility in ileum