GI 11 Flashcards
What are the two Plexuses in the GI tract?
- Submucosal Plexus
* Myenteric Plexus
What are the two types of Neural reflex loops in the GI?
- Short reflexes
* Long reflexes
What is the Myenteric plexus more closely integrated with?
The smooth muscle layer of the intestinal wall
What are Short Reflexes in the GI tract?
Signals received by sensory neurons that innervate the sensory epithelium
Where are signals from received and integrated in the GI tract?
They are received and integrated by the neurons within the enteric nervous system
What do Sensory signals in the GI tract do after being integrated?
They signal to cells within the epithelium to generate responses or short reflexes
Where are Short reflexes integrated?
Within the wall of the intestine
Where are long reflexes sent out to be integrated?
The central nervous system
What response does a short stimulus elicit?
Either stimulates smooth muscle or exocrine glands
What can happen when a GI signal is sent to the CNS?
The signal can have a modulating role through smell and taste or the emotional response if you’re hungry and what not
What cell produces the hormones responsible for hormonal regulation in the GI tract?
Enteroendocrine cells
What does the Apical portion of the enteroendocrine cell do?
Faces the lumen and detects stimulus
What does the Basolateral domain of enteroendocrine cells do?
Hormone secretion
What do the hormones secreted by enteroendocrine cells do?
They go into the bloodstream to the rest of the body
Where is Gastrin produced?
In the stomach
What is the trigger for gastrin to be produced?
Amino acids/peptides
What is the stomachs response to gastrin?
Stimulates acid secretion and motility
Where is CKK produced?
The small intestine
What is the trigger for CKK to be secreted?
Amino acids and fat
What is the response to CKK in the stomach?
Inhibits acid secretion and motility
What is the response to CKK in the pancreas?
Stimulates enzyme secretion
What is the response to CKK in the gallbladder?
Stimulates gallbladder contraction
Where is Secretin produced?
The small intestine
What is the trigger for secretin to be produced?
Acid
What is the response of secretin in the stomach?
Inhibits acid secretion and motility
What is the response of secretin in the pancreas?
Stimulates HCO3- secretion
What is the response of secretin in the Liver?
Stimulates HCO3- secretion
What is the response of secretin in the Liver?
Stimulates HCO3- secretion
Where is GIP produced?
In the small intestine
What is the trigger for GIP?
Glucose and fat
What is the response of GIP in the pancreas?
Stimulates insulin secretion
What are the three phases of gastrointestinal regulation?
- Cephalic phase
- Gastric phase
- Intestinal phase
What is the Cephalic phase characterized by?
Sight, smell and taste
What is the Gastric phase stimulated by?
Distension, acidity, amino acids/peptides
What is the intestinal phase stimulated by?
Distension, acidity, osmolarity, and digestive products
