Slow wave or basic electric rhythm (BER) Definition: Spontaneous, slow and rhythmic fluctuation( depolarization and repolarization) on resting potential in gastrointestinal smooth muscle cells Size: 5-15mV(from -65 to-45mV Frequency: 3-12/min stomach---3: duodenum---12: ileum---8, 9 Size and frequency is influenced by neural and humoral regulation
Slow wave or basic electric rhythm (BER) Size: 5-15mV (from –65 to-45mV) Definition: Spontaneous, slow and rhythmic fluctuation ( depolarization and repolarization) on resting potential in gastrointestinal smooth muscle cells. Frequency: 3-12/min stomach--- 3; duodenum---12; ileum---8，9 Size and frequency is influenced by neural and humoral regulation
Origin: interstitial caial cells which serve as pacemaker for GI smooth muscle Mechanism: cyclic changes of the activity of Nat-K pump Function weak contraction the base of ap formation
Function: weak contraction the base of AP formation Mechanism: cyclic changes of the activity of Na+ -K+ pump Origin: interstitial Cajal cells, which serve as pacemaker for GI smooth muscle
Action potential Inducing: the depolarization of slow wave reaches tp by stimulation Characteristics: single or mutiple spikes Action: the number of spike potential determine contraction
Action Potential Inducing: the depolarization of slow wave reaches TP by stimulation Characteristics:single or mutiple spikes Action: the number of spike potential determine contraction
Mechanism depolarization: slow Ca2+-Natchannels Ca2t inward flow. Nat inward flow repolarization: Ktoutward fow
Mechanism: depolarization: slow Ca2+ -Na+channels Ca2+ inward flow , Na+ inward flow repolarization: K+ outward flow
Relationship among rp, ber and contraction SPIKES Electrical Threshold Threshold for contraction SLOW WAVES ag CONTRACTION Recordings frequency direction RP BER AP Muscle contraction rength
Relationship among RP, BER and contraction RP AP Muscle Contraction frequency direction speed strength