The process of removing chemicals from the body is known as excretion. Numerous cellular reactions generate diverse excretory products such as urea, uric acid, creatinine, bilirubin, and ammonia. Protein and nucleic acid metabolism’s breakdown products are these excretory by-products. These excretory products need to be removed from the body since a build-up of them can cause a variety of diseases. The three main excretion organs are the kidneys, large intestine, and skin.
Excretory products are eliminated through a variety of methods, including:
- Sweating: Salts, carbon dioxide, urea, and ammonia are all eliminated in very minute quantities through sweat.
- Urine: Urea, uric acid, creatinine, and ammonia are excreted by the kidneys through urine. Urine is also used to eliminate extra ions including Ca2+, Na+, and phosphates. Urine is used for the excretion of numerous medications, poisons, and even too much water.
- Feces: The body excretes minute amounts of water, inorganic salts, bacteria, byproducts of bacterial decomposition, undigested substances, and indigestible food components in feces. The majority of the bilirubin in bile is processed by bacteria in the small intestine and expelled in feces.
Human Urinary System
It has one urine bladder, two ureters, two kidneys, and one urethra. The kidneys are crucial organs in this system; the remaining components are large storage areas and connected ducts or passages.
Structure
The organs that create and move urine to the site of excretion are referred to as the urinary system. On the left and right sides of the dorsal body wall and parietal peritoneum, there are two kidneys in the human urinary system.
Kidney
Nephrons, the kidney’s functional unit, are where urine is first formed. Then, urine travels through the nephrons via a network of convergent tubules known as the collecting ducts. The minor calyces and major calyces that eventually connect to the renal pelvis are formed by the union of these collecting ducts.
From the renal pelvis, urine continues to flow into the ureter, where it is then carried by the ureter into the bladder. At the level of the urinary bladder, the anatomy of the human urinary system varies between males and females. The urethra in males starts at the internal urethral orifice in the trigone of the bladder, travels via the external urethral orifice, and eventually develops into the prostatic, membranous, bulbar, and penile urethra. The external urethral meatus is where urine leaves the body. The female urethra is significantly smaller and ends at the vaginal vestibule after starting at the bladder neck.
Functions of Kidney
- Eliminate drugs from the body
- Eliminate trash from the body
- Balance the body’s fluids
- Release of blood pressure-regulating hormones
- Create a vitamin D active form that supports strong and healthy bones
- Govern the red blood cell formation
Ureter
Each kidney has a muscular tube that connects it to the renal pelvis. The Ureter is the name of this tube. The ureter’s job is to occasionally transport urine from the kidneys to the bladder.
Urinary bladder
The organ that regulates urine transit is the urinary bladder. Urine is kept in a muscular sac-like structure that is located above the pubic bone. The typical human bladder has a 400–600 cc capacity. When the bladder is full, it releases the pee through the micturition process. Muscular tissue lines the bladder, and as the bladder contracts during micturition, the pee leaks out.
Urethra
The primary organ through which human pee leaves the body is the urethra. The excretory system diagram for the male body and the frame body shows various forms of the urethra. Because a female body has a vagina as its primary excretory organ whereas a male body has a penis, the urethra in both differs in size. The male urethra measures 8 inches in total, while the female urethra measures 1.5 inches.
Urination
The act of passing urine from the urethra to the outside of the body is known as urination or micturition. It is a method of excretion used by the urinary system. Medical terms for it include micturition, voiding, uresis, and, in rare cases, emiction. It is often referred to colloquially as peeing, weeing, and pissing.
Healthy humans and many other animals can voluntarily control the act of urinating. Urination may be a reflex in newborns, some elderly people, and people with neurological impairments. Adult individuals typically need to urinate up to seven times per day.
Urine
- Urine is a liquid waste product of metabolism that is produced by humans and many other organisms. Urine is generated from the kidney and then moves to the bladder by the ureters.
- Urination causes urine to be expelled from the body through the urethra.
- Only a small amount of nitrogen-rich waste products from cellular metabolism—urea, uric acid, and creatinine—need to be eliminated from the bloodstream. Urine serves as the body’s primary means of excreting water-soluble substances and is how these waste products leave the body.
- The nitrogenous wastes of the mammalian body can be found through a urinalysis.
- In the nitrogen cycle, urine is crucial. Urine fertilizes the soil and aids plant growth in ecosystems with a healthy balance.
- So, urine can be used by plants as fertilizer.
- It serves as a territorial marking for some animals.
- In the past, aged or fermented urine (also known as lant) was used to make gunpowder, clean homes, tan leather, and color fabrics.
Composition of Urine
Water, which makes up around 95% of pee, is its main constituent. An animal’s urine concentration will directly correlate with its water consumption. This is so that only extra water is eliminated by urine. The urine contains waste materials that are also discharged. Creatinine is another waste material found in urine. Creatinine is a waste product produced when muscles contract and the kidneys can remove it through urine. It comprises around 0.1% of urine. The key electrolytes that are present in urine and account for a significant portion of its makeup are chloride, sodium, and potassium.
Additionally, pigments are a component of urine. Urine’s hue, which typically ranges from light yellow to dark amber, is determined by pigments. Urobilin, uroerythrin, and urochrome are the three primary pigments that make up urine composition. Urine is used to eliminate hormones. Medical testing can identify certain hormones, which aids in medical diagnosis. Amino acids and metabolites are also present in urine.
Wastes products in the Bloodstream
As food passes through the stomach and intestines, the digestive enzymes break down nutrients into smaller molecules. In the bloodstream as a result of this dissolution are several harmful byproducts, which include:
- Amino acids produced by the metabolism of urea-proteins are broken down into ammonia in the liver. The liver changes it into less harmful urea because it is poisonous for the body to handle and eliminate.
- Uric acid is created when purines break down in tissues
- Muscle metabolism produces creatinine as a byproduct.
- Ketone bodies are created when excess fatty acids break down in the liver
These wastes would gradually poison the blood and cells if they were allowed to build up in the blood. The dissolved wastes in the blood are filtered by the kidneys into the urine, which is gradually excreted from the body.
Function of Urinary System
The urinary system filters your blood to get rid of things your body doesn’t need. It eliminates extra water, salt, toxins, and waste products. The numerous parts of the urinary system perform the following tasks:
- Blood filtration
- Separating essential nutrients from unwanted contaminants
- Storing and expelling urine from your body.
How does the urinary system clean blood?
- Each kidney is supplied with blood by several microscopic arteries.
- Kidneys extract nutrients and toxins from your blood.
- The bloodstream receives reabsorbed nutrients such as proteins, vitamins, minerals, and other foods.
- Urine and waste products are transported to your bladder through your ureters. Urine is stored in your bladder until you use the restroom.
- Urine is out from the body through the urethra.
Disorders that affect the Urinary System
- Infections: Urinary tract infections (UTIs) and sexually transmitted infections (STIs) can cause issues with the kidneys, urethra, or bladder (STIs). Infections like these can occur when bacteria or viruses enter your urinary tract through your urethra. Your doctor might recommend medication to treat an infection.
- Structural issues: Birth abnormalities may affect how an infant’s urinary tract develops. Urination buildup and kidney infections could result from these abnormalities.
- Urinary issues: Loss of bladder control or urinary incontinence (leaks) causes little to major urine leakage. Urinary incontinence is more common in women than in males, particularly during pregnancy or later in life. It can get worse if you laugh, sneeze, cough, or jump.
- Chronic renal disease: The most common causes of the disorder are diabetes and high blood pressure. By controlling your blood pressure and blood sugar, you can drastically lower your risk of kidney disease.
- Interstitial cystitis: sometimes called painful bladder syndrome, this condition causes inflammation of the bladder (swelling and irritation). Physical therapy and medication can be used to lessen the painful bladder syndrome’s signs and symptoms.
How to keep the Urinary System Healthy?
- Drink lots of water: Hydrating your body will help you avoid kidney stones and UTIs while also flushing out your system. To prevent a UTI, consider consuming cranberry juice. Cranberries include substances that may prevent bacterial growth.
- Eat a balanced diet: Foods high in calcium and low in sodium may help prevent kidney stones.
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Safe sex practices: Use a condom to shield yourself from an STI. However, spermicides should be used with caution as they can encourage the growth of germs.
- After having sex, empty your bladder: If you’re a woman, you should go to the bathroom. Quick urination can eliminate bacteria and lower your chances of developing a UTI.
- Practice pelvic floor exercises: Often known as Kegels, to strengthen the muscles in your pelvic floor and lower your risk of incontinence.
Clinical Significance
- Congenital or acquired malfunction of the urinary system can be a symptom of urologic illness. For instance, a urologic condition called urinary tract obstruction might result in urine retention.
- Nephrologists typically treat illnesses of the kidney tissue, whereas urologists typically treat illnesses of the urinary tract. Female incontinence may also be treated by gynecologists.
- The urogenital function is directly impacted by diseases that affect other bodily systems as well. For instance, it has been demonstrated that the kidneys’ release of protein in people with diabetes mellitus makes them more susceptible to the harmful effects of hypertension.
- Peripheral neuropathies caused by diabetes, which can happen in some people with poorly controlled blood sugar levels, can also directly affect urination.
- A weakening of the pelvic floor muscles brought on by conditions like pregnancy, delivery, aging, and being overweight can lead to urinary incontinence.
FAQs on Urinary System
Question 1: Identify the kidney’s functional unit.
Answer:
The anatomical and operational component of our kidneys is called a nephron.
Question 2: What kinds of waste do living things get rid of?
Answer:
Living things excrete three types of wastes: ammonia, urea, and uric acid. These chemical reactions produce waste materials such as carbon dioxide, water, salts, urea, and uric acid. The body suffers harm when these wastes build up outside of it. The excretory organs eliminate these wastes. The method by which metabolic waste is expelled from the body is called excretion.
Question 3: What crucial roles do the human excretory system’s organs play?
Answer:
The elimination of wastes, the removal of waste byproducts generated by the cells, preventing the buildup of hazardous chemicals in the body, and maintaining a balanced chemical concentration in the body are all critical tasks carried out by the excretory system.
Question 4: Identify the main excreted product.
Answer:
As urea is the main excretory product, humans are ureotelic creatures.
Question 5: What procedures are involved in getting rid of waste?
Answer:
The processes of glomerular filtration, reabsorption, and secretion are all part of waste elimination. These procedures just purge the body’s surplus water and waste.