The flashcards below were created by user smaddineni on FreezingBlue Flashcards.

  1. Rectoanal inhibitory reflex
    • electrical stimuli
    • induce relaxation of the internal anal sphincter
    • resultant lowering of the resting pressure

    absent in Hirschsprung's disease, Chagas disease, and after rectal mucosal excision

    may return after initially being abolished by a low rectal anastomosis.

    intramural involving myenteric plexus neurons that are noncholinergic and nonadrenergic.
  2. RAER
    • inflation reflex
    • electrical stimuli
    • reflex contraction of the external anal sphincter
    • lost at high rectal volumes (400 ml)
  3. Sampling Reflex
    reflex relaxation of the internal anal sphincter

    • fecal incontinence-Biofeedback can improve rectal
    • balloon distention thresholds.
  4. Anal Cough Reflex
    external anal sphincter contracts higher than voluntarily
  5. Cutaneoanal reflex
    • afferent and efferent pathways in the pudendal nerve
    • abolished if S4 is transected.

    • Latencies
    • short:direct stimulation of nerve fibers near the sphincter
    • intermediate:stimulation
    • to a branch point that then travels back to the muscle failing to complete the
    • complete reflex arc at the spinal level.
  6. defecation
    • superior frontal gyrus and anterior cingulate gyrus
    • Rectal distention stimulates internal anal sphincter relaxation and the sampling reflex.

    • defecation is to be deferred:
    • voluntary contraction of the external anal sphincter and levator ani muscles
    • Accommodation: relaxation of the rectal ampulla after an initial increase in pressure.

    • At the appropriate time for defecation or when rectal pressure is high, the levator ani muscle, puborectalis muscle and external anal sphincter relax.
    • Pelvic floor relaxation, along with a squatting
    • position, straightens the anorectal angle.
    • An increase in abdominal pressure along with colonic and rectal contractions allows expulsion of a fecal bolus.
Card Set:
2011-06-01 18:48:23

Show Answers: