<prompt> Tetrodotoxin blocksyNa during action potentialyK during action potentialyNa during resting stateyK during resting state  <response>: A i.e. y Na during action potentialInhibitors toxinsSodium dependent glucose transpoer SGLT or Na glucose co transpoer is inhibited by phlorizinQ whereas, phloretin inhibits sodium Na independent glucose transpoer GLUT 2 in intestineQ.Fish neurotoxin tetrodotoxin applied externally block Na channelsQ esp early membrane voltage dependent Na current; hence m gates controlling Na channels externally where as enzyme pronase applied internally block voltage dependent inactivation of Na current hence h. gates controlling Na channels from inside.Tetraethyl ammonium or 4 aminopyridine block potassium channelQ esp delyed voltage dependent increase in K permeability and hence n gate.Absorption of Hexose in intestineHexoses are rapidly and completely absorbed before the meal reach terminal ileumTranspo of most hexoses glucose galactose is dependent on Na ions in intestinal lumen; a high Na concentration facilitates and a low concenteration inhibits sugar influx into the epithelial cells.This is because Na glucose share a same cotranspoer or sympo, the sodium dependent glucose transmpoer SGLT, Na glucose cntranspoer. These SGLT 1 2 resemble glucose transpoers responsible for facilitated diffusion in that they cross cell membrane 12 times and have their - COOH - NH2 terminals on cytoplasmic side of membrane. However , there is no homology to glucose transpoer GLUT. SGLT- 1 is responsible for uptake of dietary glucose from gut where as SGLT-2 is responsible for glucose transpo out of renal tubules. 