-
Do saliva glands utilize hormones and nerves to activate?
No, they do not use hormones. Just PNS and SNS.
-
What chemicals cause constriction of GI tract?
ACH, Substance P, Enkephalins
-
What chemicals cause relaxation of GI tract (PNS)?
VIP, Neuropeptide Y, NE
-
What two types of gastrin are released and when?
- G17: during meals
- G34: between meals
-
What cells released Gastrin?
G cells in Antrum
-
What cells secrete Somatostatin?
D cells in Antrum
-
What does somatostatin inhibit?
Gastrin, HCl, Histamine
-
What cells release histamine?
ECL (enterochromaffin like cells) in Oxyntic Body
-
What are three chemical agonists of parietal cells?
histamine, Ach, Gastrin
-
What are three antagonists of parietal cells?
- Somatostatin (d cells)
- Prostaglandins
- Growth factors
-
What are the three phases of gastric secretion and their percentages?
- Cephalic (30%)
- Gastric (60%)
- Intestinal (10%)
-
Why doesn't the stomach autodigest itself?
- 1) impermeable membrane
- 2) tight junctions b/t cells
- 3) gastric mucosal barrier
-
What molecule activates when fat is in the duodenum and from what cells?
-
What are the three pancreatic endocrine cells and their secretions?
- Beta cells: Insulin
- Alpha cells: Glucagon
- Delta cells: Somatostatin
-
What ANS system stimulates pancreatic release?
PNS (vagus)
-
What three pancreatic enzymes are secreted from Acinar cells?
- 1) Protease: trypsinogen, chymotrypsinogen, procarboxypeptidase
- 2) Alpha amylase: polysaccharides into disaccharides
- 3) Lipase: TG into mono and 2 FA
-
What do pancreatic enzymes focus on degrading: fats, proteins or carbs?
Fats
-
What molecule activates trypsin?
Enteropeptidase/Enterokinase
-
Are salivary secretions isotonic or hypotonic?
Hypotonic (Start isotonic from acinar cell release)
-
Are pancreatic secretions isotonic or hypotonic?
Isotonic (start isotonic as well from acinar cells)
-
What chemical do S cells release?
Secretin
-
What is the function of secretin?
Stimulate release of Bicarb
-
What phase of digestion activates pancreatic exocrine chemical release?
Intestinal
-
What pathways do CCK and Secretin utilize?
- CCK: PLC>IP3>Calcium release>Acinar cells>enzyme release
- Secretin: cAMP>ductal cells>release Bicarb
-
What two molecules are necessary for bile salt digestion?
Pancreatic lipase + CoLipase
-
T/F bilirubin is not involved in digestion?
T
-
What are two choloretics?
- Vagus Nerve (PNS)
- Secretin (from S cells)
-
What sphinctor must be opened to release bile into intestine?
Sphinctor of Oddi
-
What is the main method of mixing in the small intestine?
Segementation
-
What is the rate of segmentation in the duodenum and ileum?
- Duodenum: 12/min
- Ileum: 9/min (gastroileal reflex)
-
What are the names of the waves in front and behind a peristaltic wave?
- Front: Caudad, relax = VIP, NO, NE, Neuropeptide Y
- Behind: Orad, constrics = Ach, Substance P, Enkephalins
-
What do glucose and galactose require on the apical membrane to enter the SI?
Na+ pump
-
How do Glucose, galactose and fructose pass through the basolateral membrane?
facilitated diffusion
-
How does fructose pass through both the apical and basolateral membrane?
Facilitated diffusion
-
What GLUT transporters are used for Glucose and galactose on the basolateral SI membrane?
GLUT 2
-
What GLUT transporter is used on the apical and basolateral membrane for Fructose?
GLUT 5
-
What are the three endopeptidases and their function?
- Pepsin, Trypsin, chymotrypsin
- cleave peptide bonds
-
What is the one exopeptidase and its function?
- Carboxypeptidase
- **cleave AA from ends
-
What type of transporter do AA use on the apical membrane of SI?
Na dependent
-
How do AA pass the Basolateral membrane?
facilitated diffusion
-
What two amylases can digest polysaccharides?
- Salivary Amylase
- Pancreatic Amylase
-
T/F villi are present on the LI
F
-
What does the LI extract?
H2O and salt
-
What type of contractions does the LI utilize?
Haustral
-
How often does a Haustral contraction occur and where?
-
How often does a mass movement occur and where?
-
Do both sphincters relax or contract during nonactivity?
Contract
-
If flow rate is increased in the LI, what happens to K amounts?
decrease = hypokalemia due to secretion
-
What chemical activates Na and H2O absorption in the LI?
Aldosterone (from RAS)
-
What type of secretion is released from LI goblet cells?
Mucous
|
|
