Physio Hormones Flashcards
Salivary glands receive input from
PNS and SNS
BOTH enhance secretions (unique)
SNS: Celiac ganglia contribute to gut all the way up to distal colon, then at Distal,
the Sup/Inf Mesenteric ganglion take over
Where is CCK made
I cells of duodenum and jejunum
Where is Gastrin made
G cells of stomach
Where is Secretin made
S cells of duodenum
Where is GIP made
Duodenum and jejunum
Gastrin
Release of H in stomach, Gastric mucosa growth
CCK
Acts at various locations (Pancreas, gallbladder)
GIP
Increase insulin secretion
Slow stomach stuff: decrease emptying and H+ secretion
Secretin
Increase BICARB secretion
GIP released in small intestine as result of
Presence of breakdown of food stuff
(+) Insulin release
(-) gastric H secretion and emptying
Why can we respond so quickly to oral glucose?
Thx to GIP: Glucose dependent Insulinotropic Peptide
GI Paracrines (2)
Somatostatin
Histamine
Main GI Hormones (4)
Gastrin
CCK
Secretin
GIP
Main GI Paracrines (2)
Somatostatin
Histamine
Main GI Neurocrines (5)
Ach NE NO VIP GRP
BER (Basal electrical rhythm) originates in
Interstitial Cells of Cajal
“pacemaker cells”
(in Myenteric plexus)
What factor of BER is unchanged by neurocrines?
Frequency
Unchanged. Only depends on location in GI tract
Migrating Motor Complex is regulated by
Motilin
MMC function
“housekeeping”
remove un-digested food- propel it forward
every 90 min
MMC
Interdigestive
starts 2 hrs after eating
Cephalic phase
Nervous component
Hormonal component
Prep the whole GI tract for food
Cephalic phase: PNS
PNS increases secretion of saliva, gastric acid, gastrin, and pancreatic enzymes
Major components of Saliva
Mucus A-amylase Lingual lipase Alkaline solution IgA
Saliva is _____ to plasma
Hypotonic
What is higher in saliva than plasma?
K and Bicarb
A high saliva secretion rates,
Saliva starts to look more and more like plasma (except for Bicarb)
As saliva secretion increases
Bicarb increases (prevent reflux)
Why is saliva hypotonic?
More NaCl is removed than Bicarb and K put back in
removing more electrolytes than returning
PNS stimulation of saliva
ACh and VIP
What drug interferes with ACh on Muscarinic receptor
Atropine
What inhibits saliva production
Fear
Dehydration
Sleep
What stimulates saliva production
Conditioning
Food
Nausea
Smell
Organization of stomach
Longitudinal
Circular
Oblique
Vagovagal reflex
Release of VIP, relaxation of LES and Orad stomach (allowing passage of food from Esophagus to Stomach)
What is the Alkaline tide
Bicarb being secreted into the blood as a result of the HCl being secreted into gut lumen
Blood becomes more basic
What 3 substances have a Synergistic effect on H+ release into lumen?
ACh
Gastrin
Histamine
H+ release, 3 important contributing factors
ACh –> M3 receptor
Gastrin –> CCKB receptor
Histamine –> H2 receptor
How does Cimetidine work?
Medicine
Blocks Histamine from binding to H2 receptor
Histamine (a paracrine)
leads to increased H+ secretion
Proton pump creating H+
Ach, Gastrin, and Histamine acting on PARIETAL CELL
What 2 substance inhibit H+ secretion from PARIETAL CELL
Somatostatin
Prostaglandins
Cimetidine
Ramitidine
H2 blocker med
PPI (H-K ATPase blocker)
Omeprazole
