I know this post is a major departure from talking about plants and recipes. But, I am in a Human Anatomy and Physiology class this semester and we have been learning about some really interesting stuff. Today I wanted to share with you what I have been learning about the kidneys. I hope you find it interesting and it might even give you motivation to drink more water :).
The kidneys are an incredible organ that are involved in many different physiological processes in the body. They are part of the Urinary System and besides filtering fluids, they also release hormones that stimulate bone marrow to synthesize blood, and they function in directly and indirectly controlling blood pressure.
Today we will talk about how the kidneys control chronic low blood pressure. The filtering mechanism of the kidney is driven by blood pressure. So, proper pressure is very important for them to function properly. Water contributes to blood pressure so when we don’t have enough water in our bodies, blood pressure goes down and there isn’t enough blood volume for the heart to get blood where it needs to go. The cliff notes version is… an enzyme is released by the kidneys which binds to a plasma protein from the liver which gets converted to another protein by another enzyme which act to trigger several outcomes.
The one that I want to focus on today is the release of Aldosterone (a hormone produced in the pituitary gland) that tells the kidneys to reabsorb Sodium and water follows by osmosis. Osmosis just means the diffusion of water to an area of higher concentration. So, when there is a higher concentration of Sodium in the kidneys, water would diffuse to the kidneys to water it down and urine would be excreted. However, when Sodium is reabsorbed the water goes to the area of higher concentration (in the blood) and it raises the volume of blood which means the blood pressure would go up. Higher volume in a same amount of space, results in a higher pressure.
The interesting thing about Aldosterone is it is also released in periods of long term stress. It carries out the same function and triggers the kidney to reabsorb Sodium and water follows by osmosis.
So, if you were wondering, that is why watching your Sodium intake is important when you have high blood pressure, especially if it is resulting from stress. Because, one of your body’s response to long term stress is to release a hormone that tells your kidneys to retain sodium and water by default.
When you are stressed it is especially important to drink enough water because your body is already holding on to extra sodium from the hormones released in response to stress, we don’t need more of those hormones telling the kidneys to keep retaining Sodium because we don’t have a high enough blood volume.
Basically, drinking water is so important. I could go on forever about the reasons why. But, just the one we discussed today is a good one. Drinking water is important for proper blood volume so the kidneys can perform their function of filtering the fluids in our body and ridding the body of waste.