What is the significance of the kidneys?

Beans look like kidneys. You can live freely without kidney-like beans, but life without kidneys is impossible. The kidneys perform several important functions. They filter the blood. The body is freed from waste and regulates water and salt levels in the body. 

Kidneys

The kidneys are important organs  homeostasis  for maintaining The kidney performs several homeostatic functions.

• Maintain fluid volume in the body. 
• Maintain the body’s mineral salt balance.
• Removes urea and uric acid derived from ammonia from the body.

There are too many blood vessels in the kidney. The functional and structural unit of the kidney is a very small  nephron. Every kidney contains over a million nephrons.  . Inside the nephron is a Bowman capsule and a twisted tube. Twice a capillary network is formed. The fluid produced in it is called urine, which contains waste. Urine contains water and nitrogen-containing wastes.  Urine  a large tube kidneys into the bladder.

The kidneys are constantly filtering blood and urine is constantly being produced. The amount of urine produced depends on the amount of fluid taken in during the day. The human body loses water along with sweat during excretion, along with exhaled air in the form of water vapor and during urination. 

Blood

Urine production Stages of urine production:

1. enters the kidney through the renal artery. It is excreted in the kidneys and forms a capillary network. Capillaries and nephrons are located very close to each other. 
2. The area of ​​the capillary lumen entering the nephron is larger than that of the capillary exiting it. This creates a pressure difference that causes water, salts, sugar and urea to pass from the blood through the capillaries into the nephron.  
3. The fluid that enters the nephron at this time is called the primary urine. 
4. Water and salts move to the second part of the nephron – the twisted tube. 
5. By reabsorption from the twisted tubes, the compounds needed by the body are returned to the blood. 
6. This is how secondary urine is produced. 
7. Blood comes out of the kidneys through the renal vein, which contains less waste than the blood that enters the kidney. 
8. Urine passes into the urethra, where it enters the bladder and is released in the form of urea through the urethra.

The nephron filters a glass of liquid in one minute, 180 liters in 24 hours. Only 1.5 liters of urine is excreted during the day and night. Urine enters the bladder through the urethra. Like a bladder, its volume changes through muscle contraction. Elastic walls allow a large amount of urine to enter the bladder. The bladder holds about 1½ – 2½ cups of urine. 

How do you know when you need to get rid of bladder urine? Urination  is the process of excreting urine from the body. Urine leaves the bladder through the urethra. The bladder nerves tell you when you need to urinate. As soon as the bladder is first filled, the human brain immediately receives information. You may refrain from urinating, however, the frequency of the signals coming after the bladder is even more filled intensifies. Consequently, the desire to urinate also strengthens. 

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Control of urine production The process of filtration and reabsorption from the brain to the

kidneys is regulated by the  pituitary gland. The pituitary gland is a pea-sized gland located in the brain. The pituitary gland produces a hormone that helps the kidneys filter water from the blood. 

The return of water to the blood is regulated by  antidiuretic hormone (ADH). Antidiuretic hormone is one of the hormones of the pituitary gland. If a person drinks insufficient water, the blood from the kidneys replenishes water. If a small amount of water from the blood passes into the urine, what color will the urine be? It will be darker because such urine is concentrated.  

If a person drinks a large amount of water, there is a lot of water in the blood. At such times the pituitary gland produces a small amount of antidiuretic hormone, which means that less water is absorbed by the kidneys. The amount of urine is also large. What color will it be? 

Summary

• Primary urine is produced by filtration.
• Secondary urine is produced by re absorption.
• Anti-diuretic hormone regulates the amount of water in the urine.