Amber Lauer
Aug. 14th, 2020
Unit #4 Assignment
SC235 Biology
The Kidneys
What are kidneys? Your kidneys are two bean-shaped like organs in your “renal system,
located in the upper retroperitoneal region of the abdomen.” The purpose of the kidneys is to
remove and eliminate waste from the body. But that’s not the only function of the kidneys. While
removing waste is definitely an important job, another function the kidney does is filter the
blood. Even though the kidneys are fairly small, they perform so many crucial functions.
“Filtering and regulating minerals from blood, filtering waste from food, medications, and toxic
substances, regulating pH balance, creating hormones that help produce red blood cells, promote
bone health, maintaining fluid balance, and regulate blood pressure” are just a few things that the
kidneys do.
“Our bodies are mostly made of water. But did you know that excessive water in the body
can dilute the blood and negatively affect the environment that the cells need to operate. On the
other hand, insufficient water can cause circulatory shock and neurological dysfunction.” That’s
where the kidneys come in. Our kidneys are equipped to control the correct amount of water that
should be in our body. During the filtering process, the right amount of water and chemicals
(such as sodium, phosphorous and potassium) remain in the blood. The extra water, chemicals
and wastes form urine, which flows from the kidneys through the ureters and into the urinary
bladder. It is an essential function for the kidneys to be able to maintain the precise volume of
water in the body because if they are unable to operate, the result could be serious illnesses such
as high blood pressure. Salt is regulated through a similar process.
The blood that processes through the kidneys go through a filtration function which
removes all of the toxic waste. Once the kidneys have done their job of filtering the blood and
removing the waste products from it, the next step is to get rid of the wastes from the body
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The Kidneys
through urine excretion. If too much waste products accumulate in the blood stream, then a life
threatening illness can eventually cause death.
Did you know that the kidneys processes about 200 quarts of blood every day and filters
out about 2 quarts of waste products? To be able to handle this kind of volume of blood, the
kidneys are equipped with about a million blood vessels located within the microscopic
structures of the kidneys, called nephrons. The main job of nephrons is to filter the blood to
remove waste products.
Any kind of waste that the body cannot use, is harmful. This could be a substance or
chemical and it is crucial that the waste gets eliminated from the body as quickly possible. Since
the kidneys are the main organs to the urinary system, its responsibility is eliminating the
metabolic wastes from the body. As our body’s intake food, the body pulls out the nutrients from
the food, and uses it to maintain vital bodily functions. Once the nutrients are extracted, waste
products are left behind in the blood and the bowels.
Maintaining blood-pressure is also another kidney function. This is successful by
hormonal reactions. An enzyme, Renin, is produced by the kidneys to help control the balance
between blood pressure and electrolyte. Let’s say your blood-pressure started to drop, for an
example. The kidneys will release the enzyme renin. That enzyme will convert from a blood
protein into a hormone called angiotensin. Now what angiotensin does is induce the adrenal
gland. This entices it to release another hormone called aldosterone. Aldosterone causes sodium
and water to be reabsorbed back into the blood, and now your body just increased the blood-
volume and blood-pressure.
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The Kidneys
When it comes to the kidneys, the epithelial tissue provides the essential functions needed
for protection. Each kidney is held in place by connective tissue, or in this case, renal fascia.
Surrounded by a thick layer tissue, called perirenal fat, this kidney has what it needs to be
protected.
By this point, you can probably tell that the kidneys produce a lot of important hormones,
like one called erythropoietin. This hormone plays a key role in the production of red blood cells
in the bone marrow. The kidneys can detect a decline in the red blood cells and when it does it
produces erythropoietin. When this hormone releases into the bloodstream, the bone marrow
triggers for production and release of more red blood cells.
Fun fact, did you know that vitamin D is also a function of the kidney. The kidneys job is
to convert calcidiol to calcitriol, which is an active form of vitamin D. What happens is once it is
in active form, the vitamin D reassures that calcium gets absorbed by the small intestine and
makes it available for bone development.
I didn’t realize until I did the research that the kidney is actually a hard-working organ
and that it plays a huge but important role in your health and in your life as well. That you have
to have at least one healthy kidney, or your quality of life will be unquestionably affected.
Hopefully, you now have a better understanding of some the functions the kidney does and will
do whatever you can to take care of yourself.
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The Kidneys
Reference:
Kidney Chat. 2020. Function of The Kidney.
https://www.kidneychat.com/function-of-the-kidney
Jewell, T., 2018. Kidney: Function and Anatomy, Diagram, Conditions, And Health Tips.
https://www.healthline.com/health/human-body-maps/kidney#nephrons
Training.seer.cancer.gov. 2020. Kidneys | SEER Training
https://www.training.seer.cancer.gov/anatomy/urinary/components/kidney.html
