Digestive System

  1. Functions/Processes of the Digestive System
    • Mechanical Digestion
    • Chemical Digestion
    • Propulsion
    • Absorption
  2. Most contractions are rhythmic which are triggered by frequencies of “___” membrane potential in smooth muscle of the GI tract.
    slow wave (type of graded potential)
  3. The cause of slow waves is not known entirely but it is thought that specialized cells called “____” act as pacemaker cells for the smooth muscle.
    interstitial cells of Cajal
  4. When slow waves reach -40mV a __ (action potential) is generated
    spike potential
  5. __ channels open and close slowly causing spike potentials to have long durations (10-20ms): Depolarization occurs.
    Ca++/Na+
  6. Factors that make the resting membrane potential more positive include:
    • Stretching of the smooth muscle
    • Acetylcholine released from the Parasympathetic Nervous System
    • Specific gastrointestinal hormones
  7. Factors that make the resting membrane potential more negative include:
    Norepinephrine and epinephrine
  8. Two Plexuses
    • Myenteric (Auerbach’s) Plexus
    • Submucosal (Meissner’s) Plexus
  9. The myenteric plexus controls __
    gastrointestinal movements
  10. The submucosal plexus controls __
    gastrointestinal secretions and local blood flow
  11. G cells produce __
    gastrin
  12. I cells of the small intestine release __
    cholecystokinin (cck)
  13. S cells of the small intestine release __
    Secretin
  14. basic propulsive movement of the GI tract
    Peristalsis
  15. Parietal cells secrete __
    HCl & intrinsic factor
  16. Chief cells secrete __
    pepsinogen
  17. Phases of Pancreatic Secretion
    • Cephalic
    • Gastric
    • Intestinal
Author
sophathida
ID
322614
Card Set
Digestive System
Description
Functions/Processes, Electrical Activity of GI Smooth Muscle, Enteric Nervous System, Movement of GI Tract, Gastric & Pancreatic Secretions
Updated