10 Regulation Of Function Flashcards
What are the effector cells of autonomic nervous innervation
Smooth muscle cells
Secretary cells
Blood vessels
Endocrine cells
What are the functions of GI endocrine system
- Regulation of the mechanical processes (Contraction of smooth muscle cells, gall bladder and sphincters)
- Regulation of chemical and enzymatic processes (Secretions from cells or glands)
- Post absorptive processes to prepare body for glucose regulation and food intake (GIP stimulates insulin release; PYY3-36 suppress appetite)
- Effects on growth and developments (GLP-2 promotes growth)
Give examples of paracrine molecules
Somatostatin
Histamine
What is the effect of high concentrations of secretin
Delays gastric emptying and gastric acid release
What are the effects of CCK
Release of pancreatic enzymes/zymogens
Contraction of gall bladder
Delays gastric emptying
Decreases food intake and meal size
What is GIP and its function and where is it secreted
Glucose-dependent insulinotropic peptide and it ismsecreted by K cells in response to a meal
It stimulates the release insulin
Released predominantly in duodenum and jejunum
What is PYY and its functions and where is it secreted
It is secreted from ileum, colon and rectum
Released by L cells post-pradially
It reduces GI motility, gall bladder contraction and pancreatic enzyme release. It also inhibits intestinal fluid and electrolyte secretions
PYY is truncated into PYY3-36 to inhibit food intake
Name the 3 plexuses in the GI wall and what they regulate
Myenteric (Auerbach’s) plexus is found between circular and longitudinal muscles which control gut motility
Submuscosal (Messiner’s) plexus is found in submucosa and mainly involves in sensing lumen environment to regulate blood flow and endocrine secretion
Minor plexus: includes deep muscular plexus (inside circular muscle), and the ganglia supplying biliary tree and pancreas
What sympathetic nerve innervates foregut, midgut and hindgut. What is the neurotransmitte and what does it do
Foregut and midgut are innervated by thoracic splanchnic nerve and the rest by lumbar splanchnic nerve
Noradrenaline
Usually inhibit GI function
What parasympathetic nerve innervates the gut and what neurotransmitter is used.
Foregut and midgut by vagus and the rest by pelvic nerves
Acetylcholine
What functions of the GI tract do extrinsic neuronal activation regulate
Smooth muscle
Secretly cell
Endocrine cell
Blood vessels
Name an analogue of somatostatin
Octreotide
What are the functions of ENS
Blood flow Motility Transport Secretion Absorption
