BIOL 373 COMPREHENSIVE EXAM PREP
QUESTIONS AND SOLUTIONS VERIFIED
STUDY RESOURCE
●● Disgestion
Answer: break macromolecules into forms that can be transported across
epithelium
●● Absorption
Answer: Transport nutrients, water, ions, vitamins, across epithelium
●● Secretion
Answer: release of enzymes into gut limen
●● Motility
Answer: keep the gut contents moving
●● additional considerations of GI functions
Answer: dont digest itself, dont let in pathogens, maintain water levels
●● What happens when gut barrier breaks down?
Answer: starts to digest itself, creates peptic and duodenal ulcers
,●● What is pathogen entry into GI tract mediated by?
Answer: epithelial barrier, mucus, digestive enzymes, acid, GALT
●● What is GALT
Answer: gut associated lymphoid tissue, needs to reach to pathogens but
not foreign proteins in food
●● Generic mucosal surface
Answer: epithelium (epithelial tissue)
lamina propria (connective)
muscalaris mucosa (muscle)
submucosa (connective) + meisnner's plexus (neural)
smooth muscle (circular and longitudinal)
serosa (epithelium
●● Why are there additional oblique muscles in the stomach smooth
muscle layer?
Answer: whole thing contracts, needs to contract in more dimensions
,●● What are rugae?
Answer: folds in the stomach that can flatten to expand the stomach
volume
●● first section of the small intenstine
Answer: duodenum
●● Plica in the small intestine (fold/do not fold) like stomach rugae
Answer: do not fold
●● What are peyers patches?
Answer: collections of immune cells in the end of the small intestine
only histologically relevant presence of immune system in GI tract
●● Three hierarchical ways to increase surface area in small intestine
Answer: plicas, each of them have villi, each villi has microvili
●● Two major patterns of contraction (gut motility)
Answer: peristalsis (moving food from mouth to anus)
segmental contractions (mixing and churning, maximizes exposure to
enzymes and epithelium)
, ●● Movement difference between peristalsis and segmental
Answer: segmental has alternating segments contract, little to no net
forward movement
●● What kind of smooth muscle is small intestine
Answer: single unit, all connected by gap junctions
●● Why are some regions in the gut tonically contracted? what does it
mean
Answer: it means contracted for minutes to hours
keeps food from moving back
●● What are migrating motor complexes?
Answer: Contractions in fasting that repeat every 90 to 120 minutes to
lower bacterial counts in the gut.
●● What are slow waves?
Answer: Oscillating membrane potentials inherent to some GI smooth
muscle
dont always reach threshold
QUESTIONS AND SOLUTIONS VERIFIED
STUDY RESOURCE
●● Disgestion
Answer: break macromolecules into forms that can be transported across
epithelium
●● Absorption
Answer: Transport nutrients, water, ions, vitamins, across epithelium
●● Secretion
Answer: release of enzymes into gut limen
●● Motility
Answer: keep the gut contents moving
●● additional considerations of GI functions
Answer: dont digest itself, dont let in pathogens, maintain water levels
●● What happens when gut barrier breaks down?
Answer: starts to digest itself, creates peptic and duodenal ulcers
,●● What is pathogen entry into GI tract mediated by?
Answer: epithelial barrier, mucus, digestive enzymes, acid, GALT
●● What is GALT
Answer: gut associated lymphoid tissue, needs to reach to pathogens but
not foreign proteins in food
●● Generic mucosal surface
Answer: epithelium (epithelial tissue)
lamina propria (connective)
muscalaris mucosa (muscle)
submucosa (connective) + meisnner's plexus (neural)
smooth muscle (circular and longitudinal)
serosa (epithelium
●● Why are there additional oblique muscles in the stomach smooth
muscle layer?
Answer: whole thing contracts, needs to contract in more dimensions
,●● What are rugae?
Answer: folds in the stomach that can flatten to expand the stomach
volume
●● first section of the small intenstine
Answer: duodenum
●● Plica in the small intestine (fold/do not fold) like stomach rugae
Answer: do not fold
●● What are peyers patches?
Answer: collections of immune cells in the end of the small intestine
only histologically relevant presence of immune system in GI tract
●● Three hierarchical ways to increase surface area in small intestine
Answer: plicas, each of them have villi, each villi has microvili
●● Two major patterns of contraction (gut motility)
Answer: peristalsis (moving food from mouth to anus)
segmental contractions (mixing and churning, maximizes exposure to
enzymes and epithelium)
, ●● Movement difference between peristalsis and segmental
Answer: segmental has alternating segments contract, little to no net
forward movement
●● What kind of smooth muscle is small intestine
Answer: single unit, all connected by gap junctions
●● Why are some regions in the gut tonically contracted? what does it
mean
Answer: it means contracted for minutes to hours
keeps food from moving back
●● What are migrating motor complexes?
Answer: Contractions in fasting that repeat every 90 to 120 minutes to
lower bacterial counts in the gut.
●● What are slow waves?
Answer: Oscillating membrane potentials inherent to some GI smooth
muscle
dont always reach threshold
