Motility of gut

Question 1

GI tract [5]

Answer 1

the mouth 
the esophagus 
the stomach
the small intestine
the large intestine

Question 2

Accessory glands [4]

Answer 2

the salivary glands,
the liver
the gallbladder
the pancreas

Question 3

Sphincter

Answer 3

Smooth muscle

Question 4

Mucosal layer [2]

Answer 4

Exocrine gland cell

Endocrine cell

Question 5

Lamina propia [3]

Answer 5

Small BV
Nerve. lymph
GALT

Question 6

Muscularis mucosa [3]

Answer 6

Thin layer of smooth muscle

GI secretion and blood flow

Question 7

Submucosa

Answer 7

loose CT, large BVs, lymphatic vessels

Glands in some GI regions

Submucosal nerve plexus - Meissners plexus - regulates blood flow and secretion

Question 8

Musculares externa

Answer 8

Thick muscle
2 substantial layers of smooth muscle (inner circular)
Myenteric nerve plexus = Auerbach’s

Question 9

Serosa

Answer 9

Connective tissue and connect to abdominal wall

Question 10

Intrinsic pathway

Answer 10

Enteric nervous system

Functionally organised as submucosal plexus and myenteric plexus

Question 11

Myenteric plexus

Answer 11

Auerbach’s
Control gut motility

Innervate longitudinal and outer lamella of circular smooth muscle layer

Question 12

Submucosal plexus

Answer 12

Meissner
Coordinate intestinal absorption and secretion

Innervate glandular epithelium
Project mainly to inner lamella of circular muscle layer

Question 13

Extrinsic pathway

Answer 13

Gut brain axis

ENS linked to CNS via sensory and motor nerves of PNS and SNS

Question 14

Parasympathetic

Answer 14

Preganglionic vagus n innervate oesophagus, stomach, small intestine, liver, pancreas, caecum, appendix, ascending colon, traverse colon

pelvic nerve innervates remainder of the colon via hypogastric plexus.

Parasympathetic activity stimulates motility and secretions.

Question 15

Sympathetic

Answer 15

Preganglionic fibres from T8-L2. Postganglionic cell bodies in celiac, inferior and superior mesenteric ganglia.

Sympathetic activity inhibits gut motility and secretion;
constrict sphincters

Question 16

Hirsprunch disease

Answer 16

Loss of myenteric plexus - congenital

Question 17

Sensory transmitter

Answer 17

often cause nonselective cation channels in the smooth muscle cells to open; the resting membrane potential is depolarized and more slow waves cross the threshold for the generation of a spike potential.

Question 18

Inhibitory transmitter

Answer 18

often act by opening the K+ channels in smooth muscle cells, hyperpolarizing the membrane
potential and preventing the slow waves from reaching threshold.

Question 19

Migrating motor complex

Answer 19

Every 90 mins
Strong propulsive contractions - distal stomach and SI
Intrinsic GI property

Question 20

Paralytic ileum

Answer 20

temporary cessation of gut motility that is most commonly caused by abdominal surgery.

Question 21

Deglutition

Answer 21

Voluntary control
Bolus formed by mastication
Propelled to oropharynx
Tongue moves up and back against hard palate
Mechanoreceptors stimulated in pharynx-glossopharyngeal = afferent impulse

Efferent impulses from vagus, pharynx, oesophagus and palate

Question 22

Achalasia

Answer 22

Dysphagia
Failure for LES to relax
Functional obstruction

Question 23

Gastro-esophageal reflux disease

Answer 23

LES is incompetent and gastric juice flow up

Question 24

3 types of stomach motility

Answer 24

1. Storage. Ingest food faster than can be digested, aided by receptive relaxation.
2. Physical and chemical disruption - mixing.
3. Deliver resultant chyme to intestine at optimal rate – gastric emptying

Question 25

Gastric motility sequence

Answer 25

Fundus and upper stomach body relax to receive bolus

Distal stomach mixes gastric contents with gastric secretions

Peristalsis proceeds through astral contents as Antrum contracts

Question 26

Receptive relaxation

Answer 26

Increase stomach pressure = dumping and reflux
Relaxation = size increase without intragastric pressure increasing
Mediated by vagus
pressure sensors maintain at abdominal levels

Question 27

Mixing

Answer 27

Peristalsis in pylorus and Antrum

Longitudinal cells = pacemakers

Sphincter transiently open = most contents returned into distal region

Gastrin respond to food in stomach = stimulate motility

Question 28

Emptying

Answer 28

Terminal (pyloric Antrum = thicker_

Pyloric sphincter controls exit

Increase chyme induces astral contraction and opening sphincter

Question 29

Gastric contents empty at rate proportional to

Answer 29

volume, pH, physical and chemical nature
Volume (stretch receptors) in stomach promotes emptying
as contents become isotonic, empties more rapidly

Question 30

Dumping syndrome

Answer 30

Rapid emptying of gastric contents into small intestine

nausea, pallor, sweating, vertigo and fainting

Question 31

Gatsroparesis

Answer 31

Impaired or absent ability to empty stomach

severely diabetic patients who develop autonomic neuropathy

Loss of vagal stimulation to stomach impairs astral systole

Question 32

Intestinal Blind loop syndrome

Answer 32

Impaired small intestinal peristalsis can lead to abnormally high levels of bacteria and lead to diarrhea and/or streatorrhea (fecal fat excretion)-

Question 33

Hautrations

Answer 33

Segmental contractions of circular muscle divide colon and represent main motor activity of colon

Question 34

Hautral shuffling

Answer 34

Mixing movements by segmentation

Squeeze and roll to expose focal matter for reabsorption of water and electrolyte and secret mucus = lubrication