Understanding how the kidneys work to maintain blood volume and blood pressure is tricky because there are multiple methods (and hormones) that can be involved in doing this. I had a good understanding of the hormones that were involved including aldosterone and ADH, but was a little bit iffy on where renin fit into the process. Watching this video where they gave a step by step explanation of how the release of each hormone causes a cascade effect onto another organ helped me to get a better grasp of the entire process.
In all of the processes listed above there is one additional factor that plays a large part in maintaining body homeostasis and that is WATER! So its important to discuss and understand how water excess or dehydration ties into maintaining blood volume and blood pressure as well. When the body becomes dehydrated due to excessive fluid loss or a decrease in fluid intake the extracellular fluid becomes a hypertonic solution for the cells. This means that the water in the cells will move out into the extracellular fluid (following those salts or solutes like water always does!) causing the cell to crenate. On the other hand, when we have excessive amounts of fluid in the system, the cells are in a hypotonic solution. So the water in the extracellular fluid will move into the cells causing them to overfill and lyse.
Nurse's Note: Diuretics are commonly prescribed along with antihypertensive medications to treat high blood pressure. Just another example of how blood pressure and blood volume tie in together.
No comments:
Post a Comment