The Urinary System plays a very important role in the human body. It produces Urine, a waste fluid excreted by Kidneys, which it stores, and later, passes it out of the body. Urinary System works closely with the Lungs, the Skin, and Intestines to maintain the balance of chemicals in our body. Adults excretes about 1.42 liters of water per day while children would excrete lesser amount, which depends on the amount of fluid consumed by them. If a person is under medication, the amount of Urine excreted would differ.
THE PROCESS OF URINATION
Kidneys are the primary organs of the Urinary System. Blood passes through Kidney, where the proteins are broken down and Urea is separated through Nephrons, the filtering units. Each Nephron has a ball of blood capillaries called Glomerulus and a tube called the Renal Tube. Urea, along with water, and other waste particles, passes through Nephrons and the Renal Tubes, and then out of the Kidneys through two thin tubes called Ureters which are about 8-10 inches long.
This is not one-time process but, Urine is emptied in the bladder, every 10-15 seconds. Urinary Bladder is a hollow organ like a balloon. It stores Urine till it reaches its capacity that is 16 ounces. The body takes 2-5 hours to produce that much of Urine. A tube which allows Urine to pass out of the body is called Urethra.
The only difference in Male Urinary System and a Female Urinary System is the length of Urethra. Females have 1.5 inches long Urethra and Male have 8 inches long Urethra.
SIGNALS FOR URINATION
Nerves in the Bladder are responsible for sending signal to the brain to cause Urinating sensation. When Bladder reaches the maximum storage limit, Nerves emits signals that are captured by the Brain.
Brain encrypts the message that the Bladder is full and the urge to empty it intensifies. Urinating causes relaxation in muscles that tightens while emitting signals.
COMMON DISEASE IN URINARY SYSTEM
If at any point of time, during the entire process, Urine is forced back into the Kidneys, the Urine can cause a Kidney Infection. Or, when bacteria enters a Urinary Tract, it can affect the Urethra, the Kidneys, or even the Bladder causing Urine Infection. This condition is known as a Urinary Tract Infection (UTI). Such type of infection is more common in Females but can also occur in Males. Infections, including yeasts, would cause disorders in body’s reproductive Organs. While Urologists’ treat the Male Reproductive Organs, Gynecologists’ treat the Female Reproductive Organs. One of the ways to treat the infection is to use Antibiotics. But please consult your Doctor before resorting to any medication.
TYPES OF URINARY TRACT INFECTIONS, KIDNEY DISEASES, AND FAILURE
INTERNAL CYSTITIS (IC) – This is a painful chronic Bladder syndrome, wherein the Bladder loses its elasticity. It results in the Bladder being unable to hold adequate Urine.
PROSTATITIS – This infection occurs from the swelling of prostate gland and can cause urgency in Urination. Person suffering from this infection urinates more frequently compared to others along with strong pain during Urination and pain in the Pelvic Regions. It occurs only in Males as Female Reproductive System does not consist Prostrate Glands. Severity of the disease is Prostate Cancer.
KIDNEY STONES – Sometimes consuming something adulterated causes clumps of Calcium Oxalate to form in the Urinary tract, popularly known as Kidney Stones. They causes pain in the back and sides. It can even cause hematuria, resulting in blood in urine.
KIDNEY FAILURE – Medically known as Renal Failure, it is a chronic condition wherein Kidneys are unable to filter the waste from blood. It may be caused by trauma or damage to Kidneys. Renal diseases may lead to Chronic Kidney disorders and might require dialysis or even Kidney Transplantation.
BLADDER CANCER – Difficulty in urination or frequent urination are possible symptom of Bladder Cancer. It can be caused by excessive smoking too.
Please note: Before you react to any uneasiness in your body, do always consult your Doctor for a proper diagnosis.
RENAL CELL CARCINOMA – RCC is a type of Kidney Cancer which might be caused by excessive smoking, hypertension or obesity.
URINARY INCONTINENCE – excessive stress in females can cause the problem of Urine leakage, also known as Urinary Incontinence, and it has a profound impact on quality of life.
Urinary System Anatomy
Urinary system is of one of the vital system among human body parts. It consist of Kidneys, Ureters, Urinary Bladder and Urethra. The Urinary Tract is like the plumbing system, it drains Urine from the Kidney and plays an important role in maintaining the homeostasis, a set of complex processes to maintain the balance of water, ions, calcium and blood pressure in the human body.
The Kidneys are located along the wall of abdominal cavity. The left kidney is located higher than the right kidney. This is because the right side of the liver, located behind kidney, is larger compared to the left side. A layer of Adipose (fat tissues) surrounds the organ to protect it from any type of physical damage. Our Kidneys remove excessive water from the blood and filter out all impurities, metabolic waste, chemicals, and excessive ions in the form of Urine.
Ureters resemble a tube like structure that carry Urine from the Kidneys to the Urinary Bladder. It is 10-12 inch long and is present on the left as well as the right side of the body and parallel to the Vertebral Column. The flow of the Urine from the Kidney to the Bladder is due to gravity and Peristalsis (contraction and relaxation of muscles) of tissue muscles present in Ureter walls. Ureterovesical valves seal the point of entry of Ureter in to the Urinary Bladder to prevent Urine from flowing back.
Urinary Bladder is a sac like hollow organ that stores Urine. Located in body’s midline and at the inferior end of pelvis, Urinary Bladder holds the Urine that is brought in by Ureters. As the Urine pours in it, the hollow elastic walls stretches itself. The walls can stretch and hold around 600-800 milliliters of Urine.
Once the Urine is accumulated in the Urinary Bladder, urethra takes it out of the body. It is a tube like structure which passes from Urinary Bladder and extends till the exterior of the body. Urethra in females is about 2 inch long extending up to clitoris while in male is up to 8-10 inches long extending up to the tip of penis. Urethra is also a part of male reproductive system, carrying the sperms out of the body through penis. Urethral Sphincter Muscles controls the internal and external flow of Urine.
Urinary System Physiology
Kidney is majorly responsible for homeostasis by carrying several toxicity outside the body:
Ions – Kidneys extracts sodium, calcium, potassium, chloride, phosphate and magnesium and throws it out of the body in the form of Urine.
pH – Kidneys monitors the pH level in the body and regulate the hydrogen ion level along with bicarbonates to control the blood pH.
Osmolarity – Kidneys controls the amount of water filtered outside the body and maintains the osmotic balance in the body.
Blood Pressure – Kidneys continuously monitors the blood pressure to maintain the Homeostasis.
Kidneys remove excessive waste from the blood through filtration process. Our blood consists of unwanted substances coming from things we eat and drink. Kidney automatically removes excessive salts and minerals to leave just the quantity the body needs. Every day about 180 liters of blood passes through the Kidneys via the renal arteries. Millions of tiny filters, called glomeruli, inside the Kidneys separate wastes and water from the blood.
Storage and Excretion of Wastes
When the Urine passes from Ureters to Urinary Bladder, it starts filling up the bladder and when it reaches the maximum level, the brain and the spinal cord get the signal. These signals cause relaxation of the internal Urethral Sphincter and cause the sensation of needing to Urinate. Urination can be delayed as long as the Urinary Bladder does not exceed its maximum filling volume, but as the volume increases nerve signals gets stronger leading to greater discomfort and desire to urinate.
Production of Hormones
Kidneys deal with several Hormones during the entire process namely:
- Calcitriol – Calcitriol is an active form of vitamin D in the human body produced by the Kidneys from the UV radiation striking the skin.
- Erythropoietin – It is a hormone produced by the Kidneys to stimulate the production of red blood cells
- Renin – Renin is not a hormone itself, but an enzyme that the Kidneys produces to increase the blood volume and maintain the pressure
In our next blogs, we will explain you about urinary infection symptoms, Urinary Tract Infection (UTI), etc. which is one of the most common disease in India and other developing countries.
For more details about our Urinary system and the disease, please visit our website: www.centreforroboticsurgery.com