The Urinary System!!!!

We started this week by talking about the urinary system. The urinary system consists of at least one kidney, two ureters, the urinary bladder, and the urethra. The kidneys filter the blood plasma then they return most of the water and solutes into the blood stream. The rest of the water and solutes make the urine. The urine is passed through the ureters and is then help in the urinary bladder until it is passed through the urethra and out of the body.
When you eat food, your body takes nutrients and uses them to maintain all of the bodies functions. After the body takes what it needs from the food. The rest of the waste products are left in the blood stream. The urinary system works with the lungs, skin and also the intestines. All of these excrete waste. On average, adults eliminate about one to two quarts of urine every day. This number can change depending on the amount of food and fluid that adult takes in. It also depends on how much fluid is lost during sweating and breathing. The urinary system releases a waste called urea. This comes form the blood. Urea comes from foods that contains proteins. When this food is broken down, urea is carried in the bloodstream to the kidneys.
Kidneys are about the size of your fist and they are in the shape of a bean. They are located just below the rib cage. Kidneys are responsible for removing urea from the blood using small filtering units called nephrons. A nephron has a ball formed of small blood capillaries. This ball is called a glomerulus. They also have a small tube called a renal tube.
After the kidneys, the urine travels down the ureters. These are small tubes, about 8 to 10 inches long, leading to the bladder. The muscles of the ureter constrict and relax which forces the urine down away from the kidneys. Urine is moved through the ureters to the bladder about every 10 to 15 seconds.
Your bladder is balloon shaped organ that sits in your pelvis and is held in that place by ligaments. The bladder is the organ that holds urine until you are ready to go pee and empty it. In a healthy urinary system, a bladder can hole about 2 cups of urine for about 2 to 5 hours. Sphincters are circular muscles that help keep the urine from leaking. They close tightly around the opening of the bladder into the urethra. When you urinate, the brain sends a signal to the bladder muscles which says to tighten. When tightened the urine is squeezed out of the bladder. While the brain is telling the bladder muscles to tighten, it is also telling the sphincter muscles to relax. This allows the urine to exit from the urethra.