19 - GI Physiology 3

SI

Organ which serves as the ideal site for digestion and absorption

Villi and Microvilli

Structure of SI that makes it ideal for absorption and digestion

A

QC: Digestion (1) Duodenum (2) Jejenum

B

QC: Absorption (1) Duodenum (2) Jejenum

A

QC: Absorption of bile salts and minerals (1) Ileum (2) Jejenum

Bile Acids

This secretion is important for fat emulsification

A

QC: Enzyme component of pancreatic secretions (1) Acinar (2) Ductal cell

B

QC: Aqueous component of pancreatic secretions (1) Acinar (2) Ductal cell

A

QC: Pancreatic Secretion (1) PSNS (2) SNS

A

VR: (1) Bicarbonate secretion (2) pH level

A

VR: (1) Bicarbonate (2) Pancreatic amylase activity

B

VR: (1) Presence of Chyme in duodenum (2) Duodenal Segmentation

A

VR: (1) Intragastric Pressure (2)Delivery of Chyme to duodenum

A

VR: (1) Antral contraction (2)Delivery of Chyme to duodenum

B

VR: (1) Pyloric Sphincter Tone (2) Delivery of Chyme to duodenum

B

VR: (1) Delivery of additional chyme to duodenum (2) Duodenal Segmentation

Pancreas

Majority of bicarbonate comes from what organ?

C

QC: Tonicity (1) Pancreatic Acinar cell secretion (2) Plasma

B

QC: Tonicity (1) Pancreatic ductal cell secretion (2) Plasma

A

QC: Stimulated by CCK (1) Acinar (2) Ductal cell secretion

B

QC: Stimulated by Secretin (1) Acinar (2) Ductal cell secretion

A

VR: (1) Ductal cell secretion (2) pH

B

VR: (1) CCK (2) Gastric Emptying

A

QC: Secretin release (1) S cells (2) I cells

B

QC: CCK release (1) S cells (2) I cells

B

VR: (1) pH (2) Secretin release

B

QC: Secretin release at pH (1) 10 (2) 2

A

VR: (1) Secretin (2) CFTR activity

A

VR: (1) CFTR Activity (2) Cl- efflux

A

VR: (1) CFTR Activity (2) Cl-/HCO3- Antiporter

A

VR: (1) Cl- in duct lumen (2) HCO3- efflux

A

VR: (1) Cl- in duct lumen (2) Water and Salt efflux

NBC-1 and Carbonic anhydrase

2 sources of bicarbonate in pancreatic duct cells

A

VR: (1) FFA and AA (2) CCK release

CCK-releasing peptide and Monitor Peptide

2 regulatory proteins of CCK

CCK-RP

This CCK regulatory peptide is released by endocrine cells of the duodenum

Monitor Peptide

This CCK regulatory peptide is released by pancreatic acinar cells

A

VR: (1) CCK Release (2) Regulatory protein release

A

VR: (1) ACh (2) Trypsin release

A

VR: (1) GRP (2) Trypsin release

A

QC: CCK release (1) Fed (2) Fasting state

B

VR: (1) Trypsin release (2) CCK release

CCK-1 Receptor

Receptor that CCK-1 binds to

A

QC: CCK (1) Ca+ (2) cAMP mediated pathway

A

QC: ACh (1) Ca+ (2) cAMP mediated pathway

A

QC: GRP (1) Ca+ (2) cAMP mediated pathway

B

QC: Secretin (1) Ca+ (2) cAMP mediated pathway

B

QC: VIP (1) Ca+ (2) cAMP mediated pathway

CCK-1

Most potent stimuli for pancreatic acinar cell secretions

A

VR: (1) CCK (2) ACh release

A

VR: (1) CCK (2) GRP release

A

VR: (1) CCK (2) VIP release

T

T/F: VIP is inhibitory in all parts of the GI tract except the pancreas

Apical membrane

Brush border enzymes are found in which part of the enterocyte?

F; Fats doesn’t

T/F: Proteins, Carbs, and Lipids all utilize the portohepatic circulation

Medium-Chain FAs

This is the only type of fats that utilize the portohepatic circulation

A

QC: Responsible for absorption (1) Villi (2) Crypts of Lieberkuhn

B

QC: Responsible for digestion (1) Villi (2) Crypts of Lieberkuhn

A

QC: Glucose apical transporter (1) SGLT1 (2) GLUT5

A

QC: Galactose apical transporter (1) SGLT1 (2) GLUT5

B

QC: Fructose apical transporter (1) SGLT1 (2) GLUT5

B

QC: Can be saturated (1) SGLT1 (2) GLUT5

GLUT-2

Basolateral carbohydrate transporter that glucose, galactose, and fructose uses

T

T/F: Unlike carbs, proteins can be transported to the enterocytes in the form of di and tripeptides

T

T/F: Enzymes are stored in the pancreas in their inactive form

PepT1

This is the transporter responsible for the uptake of short peptides and peptidomimetic drugs

Liver

Amino acids not required by the enterocyte are transported to which organ?

B

VR: (1) Acidity of chyme (2) Lipolysis

Colipase

This substance anchors lipase to oil droplets even at the presence of bile acids

A

QC: Needs emulsification (1) Long Chain FAs (2) Medium Chain FAs

Microvillus membrane fatty acid binding protein (MVMFABP)

This membrane transporter is responsible for transporting long chain FAs

NPC1L1

This membrane transporter is responsible for transporting cholesterol

F; Passive Process

T/F: Absorption of water is an active process governed by osmotic gradients

A

QC: Water Absorption (1) SI (2) LI

T

T/F: Water is still being absorbed even in the fasting state

A

QC: Activity of transporters (1) Post-prandial (2) Fasting state

Sodium-Glucose and Sodium-AA Transporter

These 2 transporters are some of the main mechanisms of water absorption during the post-prandial state

NHE-3 and Cl-/HCO3- antiporter

These 2 transporters are some of the main mechanisms of water absorption during the fasting state

A

QC: Responsible for mixing (1) Segmentation (2) Peristalsis

C

QC: Movement of segmentation (1) Anterograde (2) Retrograde

A

QC: Movement of peristalsis (1) Anterograde (2) Retrograde

F; Proximal contraction via substance P and ACh and distal relaxation via NO and VIP

T/F: Peristalsis occurs via the proximal contraction via NO and VIP and distal relaxation via substance P and ACh

T, F, T

MTF: These SI movements occur during the post-prandial state

(1) Segmentation
(2) MMC
(3) Peristalsis

A

VR: (1) Motilin (2) MMC

A

VR: (1) Peptide YY (2) Lipid digestion

B

VR: (1) Peptide YY (2) Gastric emptying

B

VR: (1) Peptide YY (2) Intestinal motility

Terminal ileum and cecum

In which portions of the GI tract is the Ileal break present?

B

VR: (1) Gastrin (2) Ileocecal valve tone

B

VR: (1) Gastrocolic reflex (2) Ileocecal valve tone

A

VR: (1) Stomach Distention (2) Colonic motility

Gastrocolic reflex

This is a phenomenon where distention of the stomach increases mass motility and mass movement of fecal material

Ileal Break

This is the decrease of intestinal motility to ensure full digestion of lipids

Orthocolic reflex

This is the phenomenon where getting up from bed will trigger an urge to defecate

A

QC: Functions for absorption (1) Right side (2) Left side of the colon

B

QC: Functions for storage (1) Right side (2) Left side of the colon

B

VR: (1) cAMP (2) NaCl absorption in the colon

A

VR: (1) EGF (2) NaCl absorption in the colon

Butyrate

This short-chain FA regulates gene expression in colonic epithelial cells

Sodium-Monocarboxylate Transporters (SMCT1)

This colonic transporter allows the entry of short-chain FAs