LEC 1 A.P Flashcards
(34 cards)
Slow wave are produced by
interstitial cell of cajal
resting membrane potential of ICC/SM
depolarization and re-polarization from -65mV to -45mV.
slow waveمصطلح
general name for spontaneous electrical rhythm)
specific name of slow wave in GIT
Basalor Basic electrical rhythm (BER) or electrical control activity (ECA):
Slow waves is not seen in
the esophagus and the proximal portion of the stomach
Slow wave are not action potentials
spike potential→ A.P
change in resting membrane potential OF ICC cause
undulating متموج and regular slow wave
spike potential).
Slow wave when reach a threshold action potential appears
The rate of the BER in stomach
4/min
The rate of the BER in the duodenum
12/min
The rate of the BER in the distal ileum
8/min
The rate of the BER in the colon
2/min
The rate of the BER in the sigmoid
6/min
spike potential (true action potential) appears when
If the slow wave potential rise above (-40mV)
The function of the BER is
to coordinate peristaltic and other motor activity
contractions occur only during
the depolarizing part of the waves
peristalsis in the stomach becomes irregular and chaoticفو
After vagotomy or transection of the stomach wall,
سلايد 18
مراجعة
The spike potentials spike lasting as long as
10 to 20 milliseconds.
Slow wave without spike potential:
Depolarization
opening Fast Na channels
Slow wave without spike potential
Repolarization:
opening of K channels
Slow wave with spike potential
Depolarization:
opening Ca-Na channels,
Slow wave with spike potential Repolarization
opening of K channels
↑ potential
↑ contraction