Biology 3593B Study Guide - Quiz Guide: Superior Vena Cava, Sodium Nitroprusside, Natriuresis
Document Summary
Pvn, blood volume regulation, heart failure (hf) and sympatho-excitation: Parvocellular neurons of the pvn are involved in the reduction in rsna seen in isotonic volume expansion. When blood volume increases, hr, arterial blood pressure (arb) and renal. If kainic acid is added, parvocellular, but not magnocellular, pvn neurons are destroyed at sites adjacent to the pvn. 33% decrease in rsnd, in comparison to a 59% decrease in a control group. This indicates that parvocellular neurons of the pvn are an important synaptic relay site in the reflex activated during isotonic volume expansion. They used c- fos expression to identify active neurons. These fos+ neurons were found throughout both the magnocellular and parvocellular nuclei after plasma volume loading with 4% ficoli. When a balloon was inflated in the junction of the superior vena cava and right atrium, rsna was inhibited, resulting in fos+ in only a small number of parvocellular neurons (not seen in magnocellular).
