BIOL 121 Lecture Notes - Lecture 23: Collecting Duct System, Baroreceptor, Posterior Pituitary
Document Summary
Increase h2o intake = increased urine output (the opposite is also true) A major function of the kidney is also to regulate blood pressure through the adjustment of blood volume. If total body water decreases, extracellular fluid volume decreases and therefore blood pressure decreases. Made by neuroendocrine cells in the hypothalamus. Properties: peptide hormone, released into the blood when triggered. Stimulus: high plasma osmolarlity, low extracellular fluid volume low blood pressure. Sensors: osmorecepetors: increase in plasma osmolarlity causes osmoreceptors to shrink in volume which triggers adh release. Located in the hypothalamus: baroreceptors: if extracellular fluid volume decreases, adh is released by decreases actions potentials sent to the hypothalamus via the baroreceptors. Located in the aortic arch and carotid sinus. Adh increases the number of aqii channels on the luminal membrane of the collecting duct by relocation of existing channels. Cause of an increase in water reabsorption via plasma osmolarity.