Digestion Flashcards
Passage of Lipids after absorption
Lipids go through Thoracic duct to SVC
Lipids bypass the liver
Which cells make serotonin
Enteroendocrine cells
Endocrine Hormones
Gastrin Cholecystokinin Secretin GLP-1 Gastric Inhibitory Peptide
Gastric Inhibitory Peptide is made by which cell?
K Cells
Secretin is made by which cell?
S Cells
Cholecystokinin is made by which cell?
I Cells
Gastrin is made by which cell?
G Cells
Gastrin most concentrated in which region of the GI tract?
Antrum of stomach, tapers down into jejunum
Carbohydrates that are not digested
Ceullose and Alpha 1,6 in amylopectin
Function of alpha amylase
cleaves alpha 1,4 glycosidic bonds
What does SLGT-1 transport and how
Transports everything except frutose into cell using Na/K ATPase
100% uptake of glucose into the cell
How does fructose get into the cell?
GLUT-5
Not active transport
How do sugars get into the blood?
GLUT2
Not active transport, driven by concentration gradient
Differences of “brown starches”
Takes longer for brown starch to get absorbed
Glucose does not enter the blood as quickly
What is the glycemic index?
How quickly and completely CHO are absorbed and digested
i.e. how quick is the rise in blood sugar after ingestion
Which sugar has the lowest glycemic index?
Sucrose
How much digestion of proteins occurs in the oral cavity
ZERO
What initiates protein digestion in the stomach?
Acidic pH and presence of pepsin
Protein absorption is limited to which portion of the digestive tract?
Small intestine
Proteins are broken down to bi/tripeptides via which enyme?
Peptidase
Mechanism of import of amino acids into enterocytes
Symport of amino acids with both Na+ and H+
nb: presences of Na+/H+ exchanger (H+ out, Na+ in)
Which amino acids is used to make ATP at the brush border of enterocytes
Glutamine
During a fast, what happens to enterocyte volume and mucosal level after a feeding?
Mucosa level increases
Volume increases
What is the reason for villus tips in the small bowel?
Allows for recirculation of Na+ for adequate AA absorption.
nb: villus tips do not increase surface area
nb: structure of villus promotes low Po2 in tip leading to ischemia
