The urinary system, which is primarily concerned with the removal of nitrogenous waste products from the body.
The kidneys function in several capacities: as an excretory organ, maintaining electrolyte continuity, stabilizing the acid-base balance, and maintaining an adequate fluid balance. The urinary system consists of two kidneys, two ureters, a bladder, and a urethra. As the kidneys filter toxins from the blood, these toxins are deposited out of the body in urine; at the same time the kidneys are retaining those substances that help maintain a state of homeostasis within the body.
The formation of urine by the kidneys involves several steps: filtration, reabsorption, and secretion. The malfunction of the kidneys can alter one’s state of wellness drastically, and if untreated can cause irreversible damage to the kidneys and even death
The Urinary System
Excretory Passages
information about excretory passages: it is another important part or urinary system organs. it is having produced urine, it's necessary to get rid of it. It drips from the tips of the renal pyramids into the renal pelvis into the upper end of the collecting system, and flows through a series of tubes to the outside. for more info. about it
Facts about urine
- Adults pass about a quart and a half of urine each day, depending on the fluids and foods consumed.
- The volume of urine formed at night is about half that formed in the daytime.
- Normal urine is sterile. It contains fluids, salts and waste products, but it is free of bacteria, viruses and fungi.
- The tissues of the bladder are isolated from urine and toxic substances by a coating that discourages bacteria from attaching and growing on the bladder wall.
Blood Cleaning by the Kidneys
Blood Cleaning by the Kidneys
the processes performed by the kidneys in order to filter blood.
Glomerular Filtration also called "Ultra-filtration",
Tubular Reabsorption also called "Selective Re-Absorption" and
Tubular Secretion.
it occurs in the kidney nephrons
The Urinary System components
I. Macroscopic Kidneys
II. Nephrons
III. Renal Corpuscle
IV. Proximal Convoluted Tubule
V. Loop of Henle
VI. Distal Convoluted Tubule
VII. Collecting Tubules & Ducts
VIII. Blood Flow
IX. Ureter & Bladder
X. Urethra
history and discovery of urinary system
Cultural history
Since groomed bladder of slaughtered animals stable and waterproof, they served in the cultural history of mankind numerous purposes, for example, as one of the first targeted containers used for storage and transport of liquids, cheese or even of important documents. In Europe, especially pig bladders used in the slaughter house were incurred, purified and used.
In the Middle Ages were as a substitute for real glass windows with pig bladders covered wooden frame used
Child with pig's bladder.
Excerpt from Pieter Brueghel the Elder. - Children play picture
Children served dried and inflated bladder as a toy that makes Henry VIII, king of England, survived that he likes with such a pig's bladder played football, children in the country took advantage of the inflated pig bladders as early balloons. Even culinary found the bubbles use of animals for slaughter. Sun reported Vincenzo Tanaras "L'Economia del Cittadino in Villa" (The economy in the townhouse) from the year 1687 from a recipe, which was held at banquets use. It was a small pig's bladder with the yolks of eggs filled about 25, then in boiling water until the yolk was solid. The resulting ball was then in a larger, with the protein of eggs laid-filled bubble. This was now well in boiling water until the protein had become established. Thus was developed to provide a "Riesenei."
Tycho Brahe is said that he had at a banquet the emperor suffered a Harnblasenriss because Hofetikette the guests up from the table before the emperor forbade.
Until the 19th Century were due to the diet bladder stones is a frequent disease. Since the Hippocratic Oath of doctors whose treatment prohibited, formed their own profession, that of Lithotomus (stone cutter) out. The most famous representatives of the professional branch was Johann Andreas Eisenbarth.
The Inuits in Alaska believed that the seat of the soul in the bladder is. For this reason, throughout the year the bubbles shot from Robben collected. Once a year, these were artistically decorated and bladder celebration of the sea to return, so that new animals could form derived from them, then the next year could be hunted [10]. Moreover, the Inuits drums covered with the bladder of whales.
In the Swabian-Alemannic Carnival are inflated pig bladders (Saubloodere), the mating or cords to be waved, a traditional fools device. With the Saublodere noise can be generated, they serve but also to passersby or other fools to beat
urinary system information
For invertebrates with Nephridien expand these harnbildenden organs in their final for the bladder.
In the vertebrates, there are two main forms. For some female sharks (Neoselachia) and many real bone fish (Teleostei), the two ureter a blasenartige adhesions, referred to as "bladder" works.
When amphibians (frogs with certain adjustments with drought as a water body; see water reservoir frog), a number of lizards, turtles, lizards and the bridge ostriches lead the ureter into the cloaca. From the cloaca a short corridor leads into the bladder, sometimes described as Harnbeutel. For snakes, crocodiles and all other birds is no bladder trained.
Urinary Sytem Physiology
Physiology
The urine is produced in the kidneys, then in the renal pelvis and then through the ureter into the bladder emptying. Whose wall is filled by the growing stretched, by what is perceived strain sensors. This triggers parasympathetic centers in the sacral spinal reflex one, the so-called Miktionsreflex, from the contraction of the detrusor muscle in the bladder wall and a relaxation of the internal sphincter triggers. The part of this reflex located in the nerve pelvinus. Only when the conscious relaxation of the external sphincter is starts urination. This deliberate control of the external sphincter may, however, very strong filling of the bladder through the nerve pudendus derived inhibitory impulses cease to be valid.
The urination is autonomous reflexes in the sacral spinal cord controls on the higher areas of the central nervous system influence by either inhibit or stimulate. In the brainstem, specifically in the pons (bridge) are centers, the inhibiting and stimulating effect on the Miktionsreflex (Pontine Miktionszentrum, part of the Formatio reticularis). Remains found in the cerebral cortex centers, which are mainly inhibitory, but under certain circumstances can intervene stimulant. The Miktionsreflex is the main cause of urination, but the final responsibility of checking these higher centers. They inhibit the reflex, except when the urination deliberately sought, they can urination by the contraction of the external sphincter delay and they can initiate urination, by stimulating the sacral centers.
Any urination begins by the abdominal muscles are tense. This pushes the bladder and increases the pressure. This presses the urine in the bladder neck and urethra, which will strain sensors excited, and thus the Miktionsreflex triggers. Furthermore, an inhibition of the external sphincter. After undisturbed, not prematurely urination remain usually no more than five to ten milliliter urine in the bladder.
The first exercise of Harnansammlung in the bladder occurs in humans at around 80 ml. At approximately 300 to 500 ml is the need to, to empty the bladder.
Bladder
The situation and the urinary bladder in men
The bladder (Latin Vesica urinaria) is part of the urinary tract as an organ in animals and humans, in which the urine is cached. The muscular, of Urothel lined hollow lies with the people fairly well protected in a small basin. Although the kidney urine flow continuously, allowing the bladder to the human or animal urine willingly and the only time period.
The urine reached among vertebrates from the kidneys via the ureter (ureter) into the bladder. Your maximum capacity is for people depending on body size between about 900 and 1500 ml In the adult human occurs at about 300-500 ml urination, in dependence on external and internal stimuli, it can also significantly lower during filling to urination or involuntary discharge to come. When emptying the bladder closing muscles on the ground relaxed, so that the urine through the urethra (urethra) discharged.
Kidney Cancer - What is the Kidney?
An important article about kidney cancer, we need to be careful for kidney cancer and we should care our kidney with drinking 2 litter water everyday. Article :The kidneys are two bean-shaped organs that have many important functions essential for life. Among the most important are filtrating the blood, removing waste products from the blood and ensuring that the electrolytes within the blood are correct. In addition, the kidneys produce erythropoetin, a hormone responsible for the production of (the oxygen carrying) red blood cells.
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Blood Supply and Circulation
1. Each kidney receives a renal artery-a branch from the abdominal aorta.
2. Anterior and posterior branches arise from the renal artery before it reaches the renal hilum
3. Interlobar arteries arise from the anterior and posterior branches in the renal hilum and penetrate the medulla between the medullary pyramids.
4. Arcuate arteries arise from the interlobular arteries and course along the arched border between the cortex and medulla.
5. Interlobular arteries arise at right angles from the arcuates; they penetrate the cortex between the medullary rays and lie at the borders between neighboring renal lobules.
6. Many afferent arterioles arise from each interlobular artery. Each afferent arteriole supplies a glomerulus.
7. An efferent arteriole carries blood away from the glomerulus.
a. Efferent arterioles of cortical nephrons branch to form a profusion of peritubular capillaries that carry absorbed products away from the proximal and distal tubules and converge to form the stellate veins of the peripheral cortex. These drain into the inter lobular veins.
b. Efferent arterioles ofjuxtamedullary nephrons give rise to numerous straight capillary loops--vasa recta-that descend into the medulla.
8. Vasa recta arise mainly from the efferent arterioles of the juxtamedullary nephrons; some may arise from the arcuate artery. The descending parts of the vasa recta carry isotonic blood into the medulla.
The blood loses water and picks up sodium as it passes deeper into the medulla. Unlike the loop of Henle, the ascending parts of the vasa recta are as permeable to salt and water as are its descending parts. As the blood ascends through the gradient, its tonicity equilibrates with that of its surroundings.
The blood carried away from the medulla is thus once again isotonic. The passive exchange of salt and water between the vasa recta and the interstitium is known as the countercurrent exchange mechanism.
It is important in carrying away water lost to the filtrate during its descent into the medulla and thus in maintaining the osmotic gradient set up by the countercurrent multiplier system of Henle's loop.
Blood in the ascending portions of these vessels drains into interlobular veins and exits through the veins that accompany the larger arteries. Urinary system
Juxtaglomerular Apparatus
Juxtaglomerular Apparatus: Located near the vascular pole of a renal corpuscle at the point of contact between a distal convoluted tubule and an afferent arteriole, this includes juxtaglomerular (JG) cells, a macula densa, and extraglomerular mesangial cells. The JG cells, modified smooth muscle cells in the wall of the afferent arteriole, exhibit typical secretory ultrastructure and numerous PAS-positive cytoplasmic granules. Although the influence of the macula densa on the JG cells is poorly understood, below-normal blood volume, blood pressure, or levels of blood sodium causes the JG cells to secrete renin, This enzyme cleaves plasma angiotensinogen to produce angiotensin I, which is converted to its active form, angiotensin II, by enzymes in the lungs. Angiotensin II, a vasoconstrictor, increases blood pressure and stimulates aldosterone production by the adrenal cortex, thereby increasing chloride and sodium reabsorption by the distal tubule. Urinary system
Collecting Tubules and Ducts:
Distal convoluted tubule
4. Distal convoluted tubule. This final segment of the nephron lies in the cortex. Its epithelial lining is low cuboidal, with no brush border, making its lumen appear wider. Its lining cells are more basophilic than those lining the proximal convoluted tubules. The lateral cell boundaries are indistinct as a result of extensive lateral membrane interdigitations with their neighbors. The distal tubule epithelium forms a disk of tightly packed columnar cells called a macula densa at the point near the vascular pole of a renal corpuscle where it contacts an afferent arteriole. This disk may monitor the osmolarity of the fluid in the tubule lumen
5. Cortical and juxtamedullary nephrons, renal corpuscles are found throughout the cortex. While most belong to the cortical nephrons, the 15% closest to the medulla belong to the juxtamedullary nephrons. The latter group has short thick descending limbs and longer thin limbs that extend deeper into the medulla. The juxtamedullary nephrons bear the primary responsibility for setting up the osmotic gradient in the medulla.
Loop of Henle
Structure: Henle's loop, a U-shaped epithelial tube, includes thick and thin descending limbs and thin and thick ascending limbs. It extends from the proximal convoluted tubule in the cortex, dips into the medulla, and returns to the cortex, where it empties into the distal convoluted tubule. The abrupt transition from thick to thin in both arms of the U is the result of changes from low columnar or cuboidal to squamous and back to cuboidal epithelium. The change in the luminal diameter is less dramatic than that in the external diameter.
Function: A prerequisite for the production of hypertonic urine, the loop acts as a countercurrent multiplier to establish an osmotic gradient in the interstitial fluid of the medulla.
2. Proximal convoluted tubule
This epithelial tube begins at the urinary pole of the rcnal corpuscle. Its lining is simple low columnar-to-cuboidal epithelium. The lining cells have abundant long microvilli. Together they form a brush border that partly obscures the lumen and increases the surface area available for absorption. The convoluted part of the proximal tubule lies in the cortex and empties into its straight portion (also called the thick descending limb of the loop of Henle), which has a similar epithelium and function. Together, the convoluted and straight portions of the proximal tubule measure about 14 mm, making this the longest portion of the nephron.
Kidney Parts
B. Nephrons: Nephrons are the functional subunits of the kidney.
Each includes a renal corpuscle, a proximal convoluted tubule, a loop of Henle, and a distal convoluted tubule.
1. Renal corpuscle. As the blood-filtering unit of the nephron, each renal corpuscle consists of a glomerulus covered by Bowman's capsule. Together these structures form the filtration barrier. Each corpuscle has both a urinary and a vascular pole.
a. Glomerulus, This is a small tuft of fenestrated capillaries. Modified smooth muscle cells, mesangial cells, lie between the capillary loops.
b. Bowman's capsule is a double-walled epithelial chamber. Its inner wall, or visceral layer, consists of podocytes, These cells have long primary processes, from which arise interdigitating foot processes (pedicels) that grasp the glomerular capillaries like fingers around a broom handle and adhere tightly to the fused capillary-podocyte basal lamina. The outer wall--the parietal layer--is simple squamous epithelium. The chamber between the visceral and parietal layers is known as the urinary or Bowman's space,
c. Filtration barrier. Consisting of the structures that separate the capillary lumen from the urinary space, the filtration barrier includes
(l)the diaphragm-covered capillary fenestrations,
(2) the fused basal laminae of the capillary endothelial cells and podocytes, and
(3) the diaphragm-covered filtration slits that lie between the interdigitating pedicels. d. Vascular pole. This side of the corpuscle is where the afferent arterioles that feed the glomerular capillaries enter and the efferent arterioles that drain them leave. It lies opposite the urinary pole.
e. Urinary pole. This side of the corpuscle is where the proximal convoluted tubule exits.
KIDNEYS
A. General Organization: The kidneys are bean-shaped retroperitoneal organs encapsulated by dense connective tissue and surrounded by adipose tissue. Several components can be distinguished without the aid of a microscope.
1. Renal sinus. This medial concavity of each kidney contains the renal pelvis, the entering and exiting blood vessels and nerves, and adipose tissue.
2. Hilum, This consists of the renal sinus and its contents.
3. Cortex, This is the kidney's dark-staining outer region; it underlies the capsule. It contains the renal corpuscles, proximal and distal convoluted tubules, peritubular capillaries, and medullary rays.
4. Medulla, This is the kidney's light-staining inner region, which partly surrounds the renal sinus. It consists of 8-18 conical medullary pyramids whose bases abut the cortex and whose apices (renal papillae) point inward, toward the renal sinus. It also contains the collecting ducts, loops of Henle, and vasa recta. Each renal papilla, perforated by openings of the collecting ducts, is cradled by a minor calyx into which the ducts empty. Several minor calyces empty into a major calyx. The major calyces empty into the renal pelvis, which in turn drains into the ureter. 5. Medullary rays. These fingerlike extensions of medullary tissue that enter the cortex comprise clusters of collecting tubules and ducts. One medullary ray occupies the center of each renal lobule.
6. Renal lobes, Each human kidney has 8-18 lobes, the kidney's largest subdivisions. Each lobe, which consists of a medullary pyramid and its associated cortex, contains numerous renal lobules.
7. Reual lobules, Each of these subdivisions of the lobes consists of a central medullary ray and all the nephrons that empty into its collecting tubules. The borders between adjacent renal lobules are marked by interlobular arteries and veins
URINARY SYSTEM: GENERAL FEATURES OF THE URINARY SYSTEM
A. Components of the System: The urinary system includes the kidneys and the urinary tract.
1. Kidneys. These paired, bean-shaped, retroperitoneal organs are located in the posterior wall of the abdominal cavity. a. Structural and functional subdivisions, When sliced in the frontal plane, each kidney shows a dark-staining outer cortex and a light-staining inner medulla that partly surrounds the renal hilum, The hilum consists of a space, the renal sinus, that contains the larger renal blood vessels, the renal pelvis, and adipose tissue.
Each lobe consists of numerous renal lobules, each containing hundreds of nephrons, These are largely tubular structures that filter the blood, modify the filtrate to form urine, and empty into a series of collecting tubules and ducts which converge on the medulla and empty into the minor calyces. b. Blood supply. Because the kidneys are blood-filtering organs, their blood supply is crucial to their function. A pair of renal arteries--one to each kidney--branches from the aorta in the upper abdomen. Each artery undergoes successive branching to feed specialized capillary beds in both the cortex (glomeruli and peritubular capillaries) and medulla (vasa rectal).
B. General Functions of the System: The kidneys filter metabolic wastes and foreign sub stances from the blood; regulate the ion, salt, and water concentrations of the fluids that bathe the body's tissues; and produce renin and erythropoietin. It is followed by the reabsorption of important ions, small proteins, nutrients, and much of the water. These are returned to the blood in the peritubular capillaries and vasa recta in precise proportions.