T1 L4: Motility of the GI tract Flashcards
What are GALT cells?
Gut-associated lymphoid tissue cells are immune cells
What cells cause peristalsis in the intestines?
Interstitial cells of cajal (ICC)
What is the name of the nervous system that controls the GI motility and secretion in the intestines?
The intrinsic enteric nervous system (ENS)
What is the role of the extrinsic autonomic NS for?
It modifies the activity of the ENS
What are the 2 plexuses in the gut wall?
The myenteric and the submucosal
What nerves provide parasympathetic information to the extrinsic autonomic nervous system in the intestine?
Vagus and pelvic splanchnic nerves
What nerves provide sympathetic information to the extrinsic autonomic nervous system in the intestine?
Thoracolumbar innervation
What is Cholecystokinin CCK and what does it do?
A hormone secreted in response to protein, fat, and acid by the I cells of the small intestine. It stimulates pancreatic secretions, gallbladder contraction and growth of exocrine pancreas. It inhibits gastic emptying
What is Motilin and what does it do?
A hormone secreted in response to fat, acid, and nerves by the M cells of the duodenum and jejunum. It stimulates gastric and intestinal motility
What 3 things can cause depolarisation in the intestine?
Stretch, motilin and acetylcholine
What are the 2 types of contraction in the intestine?
Segmentation for mixing and peristalsis for propulsion. Movement is always aboral (away from the mouth)
What is Hirschsprungs disease?
A rare congenital absence of the myenteris plexus usually in the distal colon. This leads to functional obstruction and severe constipation because there’s a lack of peristalsis
What type of epithelium lines the oesophagus?
Non-keratinising stratified squamous epithelium
What type of muscle is found at the different parts of the oesophagus?
Upper part has striated skeletal muscle and the rest is smooth muscle
Where is the swallowing centre in the brain?
In the medulla oblongata and the pons in the brain stem