Which hormone released by the highlighted structure stimulates the release of tsh from the anterior pituitary (adenohypophysis)? which hormone released by the highlighted structure stimulates the release of tsh from the anterior pituitary (adenohypophysis)? ghrh crh ghih trh?

It is called the medulla oblongata or people usually call it medulla. it is the lower half of the brain stem continuous with the spinal cord. 

Na+ loss through sweet plus the dilution has lowered na+ concentration outside of neurons, altering the na+ equilibrium potential. sodium exists more outside the cells than inside. when na+ is lost by sweat plus the dilution( because they drink a lot of water) changes the concentration outside the cell, forcing the water to enter the cell and attempt to balance the concentration inside/outside.the problem is that the abundance of water will cause the cells to swell. most cells can adapt, however, the brain cells can't that's why the runner has confusion and can't control the muscles.  if not treated and this occurs in less than 48 hours, it can be immediately fatal .