GI1a Flashcards
What are the two channels that are used to get transport Cl- from the cell body into the lumen?
CFTR
ano1
What regulates the CFTR and ano1 channels?
CFTR: cAMP
ano1: IP3 > Ca++ > ano1
What three glands secrete saliva?
a. parotid
b. mandibular
c. sublingual
What type of saliva, and what percent, do the sublingual, parotid and mandibular glands secrete?
parotid: watery, 25%
mandibular: mixed, 70%
sublingual: mucous, 5%
Does the parasympathetic or sympathetic nervous system control salivation? What receptors are used?
They are both used!
Parasympathetic: ACh > muscarinic receptor, IP3/Ca++
Sympathetic: NE > beta > cAMP
What cells secrete the fluid in the intestine?
Crypt Cells
What are the 3 rules of fluid reabsorption?
a. drive by active transport of Na+
b. Cl- follows Na+
c. water follows NaCl
During reabsorption, what is coupled with Na+?
Glucose and AAs.
Does Na follow Cl, or vice versa?
Secretion: Na follows Cl
Absorption: Cl follows Na
What are the 5 ways to test for colon cancer?
a. fecal occult blood testing
b. sigmoidoscopy
c. colonoscopy
d. virtual colonoscopy
e. genetic based stool testing
What are three types of poly shapes?
a. pedunculated: mushroom
b. sessile: just the mushroom cap
c. flat: height < 1/2 diameter
What are 4 genetic/chromosomal changes associated with colon cancer?
a. APC
b. P53
c. Kras
d. Chromosome 18
What are two types of inherited adenomatous polyp syndromes?
a. familial adenomatous polyposis (FAP)
b. Lynch Syndrome (HNPCC)
What gene is associated with FAP? Lynch Syndrome?
FAP: APC
Lynch: MMR
Lynch is associated with germline mutations in any one of which 5 genes?
a. MSH 2
b. MSH 6
c. MLH1
d. PMS1
e. PMS2
Where do Lynch symptoms first appear? Second?
Colon.
Extra-intestinal (uterus, ovary, stomach, ureter, pancreas, etc.)
What does GLUT5 transport? GLUT2? sglt1?
GLUT5: fructose
GLUT2: fructose and glucose
sglt1: glucose, galactose and Na+
What is the enzyme that turns trypsinogen into trypsin?
enterokinase.
Creatinine is the breakdown product of what? Which is the breakdown product of what?
Lean muscle > creatine > creatinine
What “-lase” is contained in the watery (serous) secretions?
alpha-amylase
Does a low flow rate result in a high or low tonicity in the salivary ducts?
Low flow = Low To-nicty
What genetic marker is occurs in 100% of celiac patients and 20-40% of the general population?
HLA-DQ2 and HLA-DQ8
What are the three most important stimulants of gastrin secretion?
a. distention
b. AAs
c. peptides
What two neurotransmitters cause the release of gastrin?
a. Ach
b. GRP
What inhibits gastrin release? What inhibits this inhibitor?
Somatostatin. This is inhibited by low pH and parasympathetics.
What is the Zollinger-Ellison syndrome?
Tumors that secrete gastrin (gastromas). This leads to steatorrhea.
What does CCK do to the gallbladders?
Causes it to contract and causes the sphincter of Oddi to release.
