Excretory system

The excretory system is a passive voice biological system that removes surfeit, unnecessary materials from the body fluids of an organism, then as to help maintain inner chemical homeostasis and prevent damage to the body. The double function of excretory systems is the elimination of the waste products of metamorphosis and to drain the consistency of used up and broken down components in a liquid and gaseous country. In humans and other amniotes ( mammals, birds and reptiles ) most of these substances leave the body as urine and to some degree halitus, mammals besides expel them through sweat. only the organs specifically used for the elimination are considered a part of the excretory organization. In the narrow common sense, the term refers to the urinary system. however, as elimination involves several functions that are alone superficially related, it is not normally used in more formal classifications of anatomy or function. As most healthy officiate organs produce metabolic and other wastes, the entire organism depends on the officiate of the system. Breaking down of one of more of the systems is a serious health condition, for example kidney failure.

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urinary system

The kidneys are boastfully, bean-shaped organs which are present on each side of the vertebral column in the abdominal pit. Humans have two kidneys and each kidney is supplied with blood from the nephritic artery. The kidneys remove from the blood the nitrogenous wastes such as urea, angstrom well as salts and overindulgence water, and excrete them in the shape of urine. This is done with the aid of millions of nephrons present in the kidney. The filter blood is carried away from the kidneys by the nephritic vein ( or kidney vein ). The urine from the kidney is collected by the ureter ( or excretory tubes ), one from each kidney, and is passed to the urinary bladder. The urinary bladder collects and stores the urine until micturition. The urine collected in the bladder is passed into the external environment from the soundbox through an open called the urethra .


The kidney ‘s primary serve is the elimination of waste from the bloodstream by production of urine. They perform several homeostatic functions such as : –

  1. Maintain volume of extracellular fluid
  2. Maintain ionic balance in extracellular fluid
  3. Maintain pH and osmotic concentration of the extracellular fluid.
  4. Excrete toxic metabolic by-products such as urea, ammonia, and uric acid.

The way the kidneys do this is with nephrons. There are over 1 million nephrons in each kidney ; these nephrons act as filters inside the kidneys. The kidneys trickle needed materials and waste, the need materials go back into the bloodstream, and unnecessary materials become urine and are gotten rid of. In some cases, surfeit wastes crystallize as kidney stones. They grow and can become atrocious irritants that may require operation or sonography treatments. Some stones are small adequate to be forced into the urethra .


The ureters are mesomorphic ducts that propel urine from the kidneys to the urinary bladder. In the homo adult, the ureters are normally 25–30 centimeter ( 10–12 in ) long. In humans, the ureters arise from the nephritic pelvis on the medial view of each kidney before descending towards the bladder on the presence of the psoas major muscle. The ureters cross the pelvic brim near the bifurcation of the iliac arteries ( which they run over ). This “ pelviureteric junction ” is a common site for the impaction of kidney stones ( the other being the uteterovesical valve ). The ureters run posteriorly on the lateral pass walls of the pelvis. They then curve anteriormedially to enter the bladder through the back, at the vesicoureteric junction, running within the wall of the bladder for a few centimeters. The backflow of urine is prevented by valves known as ureterovesical valves. In the female, the ureters pass through the mesometrium on the way to the bladder .

urinary bladder

The urinary bladder is the organ that collects waste excreted by the kidneys anterior to disposal by micturition. It is a hollow muscular, and distensible ( or elastic ) electric organ, and sits on the pelvic floor. urine enters the bladder via the ureters and exits via the urethra. Embryologically, the bladder is derived from the urogenital fistula, and it is initially continuous with the allantois. In human males, the nucleotide of the bladder lies between the rectum and the pubic symphysis. It is superior to the prostate gland, and separated from the rectum by the rectovesical excavation. In females, the bladder sits inferior to the uterus and front tooth to the vagina. It is separated from the uterus by the vesicouterine excavation. In infants and youthful children, the urinary bladder is in the abdomen even when empty .


In anatomy, the ( from Greek – ourethra ) is a tube which connects the urinary bladder to the outside of the consistency. In humans, the urethra has an excretory affair in both genders to pass .

respiratory system

One of the main functions of the lungs is to diffuse gaseous wastes, such as carbon dioxide, from the bloodstream as a convention separate of breathing .

Gastrointestinal tract

The large intestine ‘s main function is to transport food particles through the body and expel the indigestible parts at the other end, but it besides collects waste from throughout the body. The typical brown color of mammal barren is due to bilirubin, a breakdown product of normal heme catabolism. [ 1 ] The lower part of the big intestine besides extracts any remaining available water and then removes solid waste. At about 10 feet long in humans, it transports the wastes through the tubes to be excreted .

Biliary system

The liver-colored detoxifies and breaks down chemicals, poisons and other toxins that enter the body. For case, the liver transforms ammonia ( which is poisonous ) into urea in fish, amphibians and mammals, and into uric acid in birds and reptiles. Urea is filtered by the kidney into urine or through the gills in pisces and tadpoles. uric acid is paste-like and expelled as a semi-solid consume ( the “ white ” in bird excrements ). The liver besides produces bile, and the body uses bile to break down fats into functional fats and unserviceable waste. Invertebrates lack a liver-colored, but most mundane groups, like insects, possesses a number of blind guts that serve the similar functions. Marine invertebrates do not need the ammonia conversion of the liver, as they can normally expel ammonia directly by dissemination through the peel .

integumentary system


Sweat glands in the skin secrete a fluid waste called sweat or perspiration ; however, its chief functions are temperature control and pheromone passing. consequently, its function as a part of the excretory system is minimal. Sweating besides maintains the tied of salt in the torso. In mammals, the skin excretes sweat through fret glands throughout the body. The fret, helped by salt, evaporates and helps to keep the torso cool when it is warm. In amphibians, the lungs are identical elementary, and they lack the necessary means to the exhale like other tetrapods can. The damp, scale-less skin is therefore essential in helping to rid the rake of carbon dioxide, and besides allows for urea to be expelled through diffusion when submerged. [ 2 ] In small-bodied marine invertebrates, the skin is the most crucial excretory electric organ. That is peculiarly true for acoelomate groups like cnidarians, flatworms and nemerteans, who have no body cavities and hence no body fluid that can be drained or purified by nephrons, which is the argue acoelomate animals are thread-like ( nemertans ), flat ( flatworms ) or merely consist of a thin layer of cells around a gelatinous non-cellular inside ( cnidarians ). [ 3 ]


Like perspiration glands, eccrine glands allow excess body of water to leave the body. The majority of eccrine glands are located chiefly on the frontal bone, the bottoms of the feet, and the palms, although the glands are everywhere throughout the body. They help the soundbox to maintain temperature operate. Eccrine glands in the skin are unique to mammals. [ citation needed ] Secretions of fret from the eccrine glands play a large character in controlling the body temperature of humans. rule of body temperature, besides known as thermoregulation, is identical important when it comes to instances that bring the body ‘s temperature outside of the homeostatic temperature such as with a fever or even exercise. [ 4 ] Together these glands make up the size of about one kidney and in one day a human can perspire amounts american samoa much as 10 liters. The two functions consist of secretion of a filtrate in reception to acetylcholine and resorption of sodium near the duct when there is urine in surfeit therefore that a sweat can be surfacing the bark. [ 5 ] There are three parts to the eccrine effort gland and these are the pore, the duct, and the gland. The concentrate is the dowry that goes through the outermost layer of the clamber and is typically 5-10 microns in diameter. The duct is the separate of the fret gland that connects dermis cells to the epidermis. It is composed by two layers of cells and is between 10 and 20 microns in diameter. The gland does the actual secretion and it lies deep within the dermis. The cells that make up the gland are larger in size than the duct cells and its lumen is around 20 microns in diameter. [ 6 ]



After bile is produced in the liver, it is stored in the crust bladder. It is then secreted within the small intestine where it helps to emulsify fats in the like manner as a soap. Bile besides contains bilirubin, which is a barren merchandise. Bile salts can be considered neutralize that is useful for the consistency given that they have a function in fatty absorption from the stomach. They are excreted from the liver and along with blood flow they help to form the shape of the liver where they are excreted. For example, if bilious drain is impaired than that part of the liver will end up wasting away. biliary obstruction is typically due to masses blocking the ducts of the system such as tumors. The consequences of this depend on the site of blockage and how long it goes on for. There is inflammation of the ducts due to the pique from the bile acids and this can cause infections. If rupture of the duct takes home it is identical traumatic and even fateful. [ 7 ]


Within the kidney, blood foremost passes through the afferent artery to the capillary formation called a glomerulus and is collected in the Bowman ‘s capsule, which filters the blood from its contents—primarily food and wastes. After the filtration process, the blood then returns to collect the food nutrients it needs, while the wastes pass into the collecting duct, to the nephritic pelvis, and to the ureter and are then secreted out of the consistency via the urinary bladder .




clinical signifiance

Kidney Stones

scientifically, masses referred to as a nephritic calculus or kidney stone, or more normally, “ kidney stones, ” are solid masses of crystals that may be a variety of shapes, sizes, and textures, that can reside within one or both of the kidneys. [ 8 ] Kidney stones shape when the libra is off between the concentration of substances that pass through urine, and the substances that are supposed to dissolve them. When substances are not by rights dissolved, they have the ability to build up, and form these kidney stones. These stones are most normally made up of substances such as calcium, cystine, oxalate, and uric acid, as these are the substances that normally would dissolve within the urine. When they do not dissolve correctly and far build up, they will normally lodge themselves in the urinary tract and in this character, are normally humble enough to pass through urine. In extreme situations, however, these stones may lodge themselves within the tube that connects the kidney and the bladder, called the ureter. In this case, they become very big in size and will most likely cause great trouble, bleed, and possibly even block the flow of urine. [ 9 ] These can occur in both men and women, and studies show that around 12 % of men, and 8 % of women in America will develop kidney stones within their life. [ 10 ]


In those extreme situations, in which kidney stones are besides big to pass on their own, patients may seek removal. Most of these treatments involving kidney stone removal are done by a urologist ; a doctor who specializes in the organs of the Urinary system. [ 11 ] A park way of removal is shock wave lithotripsy, in which the urologist will shock the kidney stone into smaller pieces via laser, allowing these pieces to far pass through the urine on their own, as a normal shell of kidney stones. Larger, more good cases may demand Cystoscopy, Ureteroscopy, or transdermal Nephrolithotomy, in which the doctor will use a screening cock or television camera to locate the stone, and based on the size or site, may either chose to continue with surgical removal, or use the shock wave lithotripsy treatment. Once the kidney stone ( second ) are successfully eliminated, the urologist will normally suggest medicine to prevent future recurrences. [ 8 ]


pyelonephritis is a character of urinary tract infection that occurs when bacteria enters the consistency through the urinary tract. It causes an excitement of the nephritic parenchyma, calyces, and pelvis. [ 12 ] There are three main classifications of pyelonephritis : acute, chronic and xanthogranulomatous .

Acute Pyelonephritis

In acute pyelonephritis, the patient experiences high fever, abdominal pain and pain while passing urine. treatment for acute pyelonephritis is provided via antibiotics and an across-the-board urological investigation is conducted to find any abnormalities and prevent recurrence. [ 13 ]

Chronic pyelonephritis

In chronic pyelonephritis, patients experience persistent abdominal and flank pain, high gear fever, decreased appetite, weight unit passing, urinary tract symptoms and blood in the urine. chronic pyelonephritis can besides lead to scarring of the nephritic parenchyma caused by perennial kidney infections. [ 14 ]

Xanthogranulomatous pyelonephritis

Xanthogranulomatous pyelonephritis is an unusual shape of chronic pyelonephritis. It results in severe end of the kidney and causes granulomatous abscess constitution. Patients infected with Xanthogranulomatous pyelonephritis experience perennial fevers, anemia, kidney stones and passing of function in the affected kidney. [ 14 ]


A urine culture and antibiotics sensitivity test is issued for patients who are believed to have pyelonephritis. Since most cases of pyelonephritis are caused from bacterial infections, antibiotics are a coarse treatment option. Depending on the species of the infect organism and the antibiotics sensitivity profile of the organism, treatments may include fluoroquinolones, cephalosporins, aminoglycosides, or trimethoprim individually or in combination. [ 15 ] For patients with xanthogranulomatous pyelonephritis, discussion might include antibiotics deoxyadenosine monophosphate well as surgery. Nephrectomy is the most common surgical discussion for a majority of cases involving xanthogranulomatous pyelonephritis. [ 14 ]


In men, approximately 2-3 cases per 10,000 are treated as outpatients and 1 in 10,000 cases require admission to the hospital. In women, approximately 12–13 in 10,000 cases are treated as outpatients and 3-4 cases are admitted to a hospital. [ 16 ] The most park senesce group affected by Xanthogranulomatous pyelonephritis is middle-aged women. [ 17 ] Infants and aged are besides at an increased risk because of hormonal and anatomic changes. [ 18 ]


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