BIOL 373 Final Exam Questions and Answers (Latest 2026).

BIOL 373 Final Exam Questions and
Answers (Latest 2026)
Segmental Contraction - Correct Answers
✅mixing/churning


maximizes exposure to digestive enzymes and epithelium


alternate segments contract


little or no net movement forward


Gut Motility - Correct Answers ✅most gut muscle is a
single unit of smooth muscle connected by gap junctions
contract as a single unit


1) Tonic contraction
2) Phasic contraction


Between meals:
-migrating motor complexes


During/after meal:
-peristaltic contractions
-segmental contractions

,BIOL 373 Final Exam Questions and
Answers (Latest 2026)
Tonic Contraction - Correct Answers ✅mins to hrs


anterior part of stomach is tonically contracted
- keeps food from moving backwards)
- smooth muscle sphincters


Phasic Contraction - Correct Answers ✅secs


posterior stomach
small intestine


Slow Wave Potentials - Correct Answers ✅


Regulation of GI Function (3) - Correct Answers ✅1) Long
reflexes, integrated in CNS


2) short reflexes, integrated within gut (enteric nervous
system)


3) reflexes involving gut peptides (paracrine or travel via
blood - endocrine)


Secretions in the Gut - Correct Answers ✅1) water and ions
(into lumen, then reabsorbed)

, BIOL 373 Final Exam Questions and
Answers (Latest 2026)
2) enzymes
3) mucus
4) saliva
5) bile (from liver)


Secretion of Water and Ions - Correct Answers ✅(Na+, Cl-,
K+, HCO3-, H+)


ions secreted via membrane transporters
water follows osmotic gradient


paracellular route
-water and ions in some regions can pass between cells


Ion Secretion Transporters (gut secretion) - Correct Answers
✅Na+/K+ ATPase
NKCC cotransporter
Cl-/HCO3- exchanger
Na+/H+ exchanger (NHE)
H+/K+ ATPase


Ion Secretion Channels (gut secretion) - Correct Answers
✅ENaC