Overview of to pee Transport, Storage, and Elimination

The urinary organs encompass the kidneys, ureters, bladder, and also urethra.

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Key Takeaways

Key PointsUrine collects from the nephrons and flows right into the ureters.The ureters usage smooth muscle contractions to facilitate the flow of urine.The urinary bladder is a hollow, muscular, and also elastic organ that shop urine.Urine exits the bladder and the body through the urethra.The kidneys, ureters, bladder, and also urethra make up the urinary tract, the pathway through which pee flows and is got rid of from the body.Key Termsureter: These are two long, small ducts that carry urine native the kidneys to the urinary bladder.urinary bladder: an elastic, muscular sac located in the pelvic cavity, right into which urine indigenous the kidneys is stored prior to disposal by urination. Pee enters the bladder via the ureters and exits via the urethra.

The Urinary System


Urinary tract: The transport and also removal that urine indigenous the body adheres to the urinary tract.


The organs, tubes, muscles, and also nerves that occupational together come create, store, and also carry to pee are referred to as the urinary system, which is another name for the renal system. The renal mechanism filters the plasma of blood and regulates blood volume by excreting overfill water in the form of urine. To pee transport follows a course through the kidneys, ureters, bladder, and also urethra, i m sorry are jointly known as the urinary tract.

Urine Transport

Urine is basically water, ions, and also secreted molecules that leave the collecting duct that the numerous nephrons of the kidney and flow into the ureters. The ureters room two tubes that drainpipe urine native the kidney to the bladder.

Each ureter is a muscular tube that drains into the bladder. Smooth muscle contractions in the wall surfaces of the ureters, over time, send the pee in small spurts into the bladder, the body organ where urine is stored before it can be eliminated.

Urine Storage

The bladder is a hole muscular body organ shaped prefer a balloon. It sit in the pelvis and is hosted in ar by ligaments fastened to various other organs and the pelvic bones. The bladder stores urine until enough of the accumulates because that removal native the body. The swells right into a round shape as soon as it is full and gets smaller as soon as empty.

If the urinary system is healthy, the bladder deserve to hold approximately 16 ounces (2 cups) of to pee comfortably because that 2 come 5 hours. Circular muscles called sphincters aid keep urine from leaking. The sphincter muscle close tightly, prefer a rubber band, about the opening of the bladder into the urethra, the tube that allows urine to pass outside the body.

Urine Elimination

Nerves in the bladder are created as the bladder fills through urine and also becomes larger, which subsequently stimulates the need to urinate. As soon as you urinate, the brain signals the bladder muscles to tighten, squeezing urine out of the bladder.

At the exact same time, the mind signals the sphincter muscle to relax. As these muscles relax, urine exits the bladder v the urethra, and also leaves the body through an opened in the genital region that includes the urethra. Once all the signals take place in the exactly order, normal urination occurs, removed urine indigenous the body.


Key Takeaways

Key PointsThe ureter contains transitional epithelium and an additional smooth muscle layer in the much more distal one-third to help with peristalsis.The ureters room usually 25–30 cm (10–12 in) long and also 3–4 mm in diameter.Muscles in the wall surfaces of the ureters send the urine in tiny spurts into the bladder.Kidney stones are a common an illness of the ureter, in which a stone made of mineral obstructs the ureter.The ureter has actually a few points that constriction where kidney stones are more commonly found.Key Termstransitional epithelial tissues: Epithelial tissues that can adjust between columnar and squamous forms that are found in the ureters and the cervix.peristalsis: The rhythmic, wave-like contraction of smooth muscle tissue that deserve to propel substances through the plenty of muscular tube of the body.

The ureters room tubes do of smooth muscle fibers the propel urine from the kidneys to the urinary bladder. In the adult, the ureters space usually 25–30 centimeter (10–12 in) long and 3–4 mm in diameter. The ureter is one of the crucial organs of urinary tract the controls urine transport.

Ureter Structure and Function

The ureters room two pipe that are made out of smooth muscle and also transitional epithelial tissues, which are a form of epithelial organization that may either be columnar or squamous. Every kidney has actually its own ureter v which urine drains into.


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Human urinary system: 1) human urinary system. 2) Kidney. 3) Renal pelvis. 4) Ureter. 5) Urinary bladder. 6) Urethra (left side through frontal section). 7) Adrenal gland vessels. 8) Renal artery and vein. 9) worse vena cava. 10) abdominal muscle aorta. 11) typical iliac artery and also vein v transparency. 12) Liver. 13) large intestine. 14) Pelvis.


The ureters are lengthy tubes that have a few points of constriction, whereby obstructions are an ext common. The ureters obtain a blood supply from a couple of different major arteries including the renal and also illiac artery derivatives, and have a fairly dense nerve supply as well.

Muscles in the walls of the ureters send the to pee in tiny spurts right into the bladder, in a procedure called peristalsis. After ~ the urine enters the bladder native the ureters, tiny folds in the bladder mucosa act prefer valves to protect against the backward circulation of the urine; this are dubbed the ureteral valves. The ureteral valves duty similarly to the semilunar valves in the veins that the body, but are structurally different, consist of of transverse mucosal epithelial folds.


Ureter Pathology

Kidney stones and cancer are typical diseases the the ureter. A kidney rock can relocate from the kidney and also become lodged inside the ureter, which can block the flow of urine, as well as cause a sharp cramp in the back, side, or reduced abdomen. The impacted kidney could then develop hydronephrosis, have to a component of the kidney come to be swollen because of blocked circulation of urine.

Kidney stones are very common and also are usually clumps the aggregated minerals the are many often discovered at the constriction points in the ureter. Ureter cancer is often because of a malignant transformation of of the transitional epithelial tissue, i beg your pardon is much more vulnerable to emerging cancer cells compared to various other tissues.


Urinary Bladder

The urinary bladder is a hollow, muscular, and also distendible or elastic body organ that sit on the pelvic floor.


Key Takeaways

Key PointsThe bladder is do of transitional epithelium and has a trigone.A common bladder empties totally upon a finish discharge, otherwise it is a authorize that the elasticity is compromised.When the bladder becomes fifty percent full, stretch receptor send nerve impulses to the spinal cord, i beg your pardon then sends a reflex nerve impulse earlier to the sphincter (muscular valve) in ~ the neck that the bladder, bring about it come relax and allow the circulation of urine right into the urethra.The internal urethral sphincter is involuntary and the exterior sphincter is voluntary.The bladder plays a minor role in temperature regulation.The bladder has actually both mechanical and sensory innervation through the sympathetic and parasympathetic worried systems.Key Termstrigone: A triangle-shaped part of an organ, such as the bottom the the bladder.urine: A liquid excrement consisting of water, salts, and urea that is do in the kidneys then released v the urethra.reflex: one automatic an answer to a simple stimulus the does not require mental processing.

The Urinary Bladder

The urinary bladder is a urine storage organ that is a part of the urinary tract. The bladder is a hollow, muscular, and elastic body organ that sit on the pelvic floor. The bladder expands and also fills through urine before it is discharged into the urethra during urination.

Bladder Anatomy

The bladder is a hollow, sac-like body organ made the transitional epithelium, comparable to the ureter that feeds into it. The ureters go into the bladder diagonally native its dorsolateral floor inan area called the trigone, i m sorry is a triangle-shaped anatomical region. The urethra exits at thelowest point of the triangle the the trigone.

There are two sphincters, or muscular valves, that different the bladder from the urethra. The sphincters must open before the to pee can circulation into the urethra. The internal sphincter is under involuntary control and the external sphincter is under voluntarily control.

Bladder Physiology


The urinary bladder: The urinary bladder is composed of numerous layers of tissue that facilitate to pee storage and expulsion. The associated structures the the urinary and male reproductive tract room labelled.


When the bladder fills v urine stretch receptor send nerve impulses come the spinal cord, i beg your pardon then sends out a reflex nerve impulse back to the interior sphincter valve in ~ the neck of the bladder that reasons it come relax and permit the circulation of urine into the urethra. The interior urethral sphincter is involuntary and also controlled through the autonomic nerves.

The bladder has a boy temperature regulation function since some warmth may leaving the body in the type of urine. A normal bladder empties totally upon a finish discharge, otherwise that is a sign that that elasticity is compromised; as soon as it becomes completely void of fluid, that may reason a chilling sensation due to the rapid readjust of body temperature.

The urinary bladder typically holds 300–350 ml of urine. As urine accumulates, the wall surfaces of the bladder thin as it stretches, allowing the bladder to store larger amounts of urine without a far-reaching rise in inner pressure of the bladder.

The bladder receives engine innervation from both forgiveness fibers, most of i beg your pardon arise from the hypogastric plexuses and nerves, and also parasympathetic fibers, i m sorry come native the pelvic splanchnic nerves and also the worse hypogastric plexus. Emotion from the bladder is transmitted come the central nervous mechanism (CNS) via general visceral afferent fibers.


Urethra

The urethra is a muscular tube that connects the bladder v the external of the body and also removes urine indigenous the body.


Key Takeaways

Key PointsThe external urethral sphincter is a striated muscle that allows voluntary manage over urination.Since the urethra is much much shorter in females, they space much an ext susceptible to bacter infections or a urinary tract infection.The urethra has smooth muscle tissue, erectile tissue, and mucous membrane tissue. In males, the urethra travels through the penis and also carries semen and urine.Semen is lugged into the urethra with the vas deferens.Key Termsvagina: A fibromuscular tubular tract the is the mrs sex organ and has two key functions: sex-related intercourse and also childbirth.penis: The male sexual organ for copulation and urination; additionally the tubular section of the male genitalia (excluding the scrotum).

The Urethra

The urethra is a tube that connects the urinary bladder come the vul for the removal of fluids indigenous the body. The exterior urethral sphincter is a striated muscle that allows voluntary control over urination by managing the flow of urine from the bladder into the urethra.

The female Urethra

Female urethra: A explicate of a woman urethra.


In females, the urethra is much shorter relative come males, and also emerges over the vaginal opening. That is lining is composed generally of non-keratinized stratified squamous epithelium that becomes transitional close to the bladder. The urethra consists of three layers that tissues:

The muscular layer is a extension of the smooth muscle that the bladder.The erectile urethral organization is committed tissue the may end up being engorged v blood throughout sexual arousal.The mucuous urethral tissue room mucous membranes the line the inner of the urethra. The mucuous membranes are especially important because that protecting the urethral organization from the corrosive results of urine.

The urethral sphincter the end the bladder from the urethra. Somatic (conscious) innervation the the outside urethral sphincter is gave by the pudendal nerve, which allows the sphincter come open and also close. As the urethra is shorter in females loved one to males, castle are much more vulnerable to bacterial urinary tract infections.


The male Urethra

In males, the urethra travels v the penis and carries semen as well as urine. Semen walk not circulation through the bladder or the remainder of the urinary tract, rather it is a liquid made that sperm cells and other fluids the passes with a couple of different glands indigenous the testes to the urethra with the vas deferens. As well as semen, and also the male urethra’s higher length, that is structurally comparable to the mrs urethra.


Male urethra: A thorough view of the masculine urethra.


Key Takeaways

Key PointsIn infants, yonsei individuals, and those v neurological injury, urination may take place as one involuntary reflex.Physiologically, micturition entails coordination amongst the central, autonomic, and somatic nervous systems that stem from various centers of the brain.The mind centers that regulate urination include the pontine micturition center, periaqueductal gray, and also the cerebral cortex.Micturition consists of a warehouse phase and also a voiding phase. Stretch receptors in the bladder rise their firing rate as the bladder becomes much more full. This reasons the micturition reflex, and also increases urinary urge, and can even cause involuntary urination.Key Termsmicturition: additionally known together urination, this is the ejection the urine indigenous the urinary bladder v the urethra to the outside of the body.urine: A fluid excrement consist of of water, salts, and also urea the is do in the kidneys then released through the urethra.

Micturition, also known together urination, is the ejection the urine from the urinary bladder with the urethra come the exterior of the body. In healthy humans the process of urination is under voluntarily control. In infants, yonsei individuals, and also those with neurological injury, urination may occur as an involuntary reflex.

Physiology that Micturition

Physiologically, micturition involves the coordination that the central, autonomic, and somatic nervous systems. The brain centers that control urination include the pontine micturition center, the periaqueductal gray, and the cerebral cortex, which reason both involuntary and voluntary manage over micturition.

In males, urine is ejected v the penis, and also in females with the urethral opening. As result of sexual dimorphism, and also the positions whereby the urethra ends, males and females frequently use various techniques for urination. Micturition consists of 2 phases:

The warehouse phase: A tranquil bladder in which urine progressively fills the bladder.The voiding phase: A contract bladder that pressures the external sphincter open and also discharges urine with the urethra.

Location of urethral orifice in females: place of the outside urethral orifice in adult females. Between the vestibule and the vaginal orifice.


The muscles managing micturition are controlled by the autonomic and somatic worried systems, which open the 2 sphincters throughout the voiding phase of micturition. Throughout the storage phase the interior urethral sphincter is tense and also the detrusor muscle is tranquil by sorry stimulation. Throughout the voiding step of micturition, parasympathetic stimulation causes the inner urethral sphincter to relax. The exterior urethral sphincter (sphincter urethrae) is under somatic control and is consciously relaxed (and therefore opened) during micturition.

Many males choose to urinate standing. In females, the urethra opens up straight right into the vulva. Because of this, the urine frequently does not leave at a distance from the body and also is because of this seen as harder to control.

The Micturition Reflex

The state that the micturition reflex system is dependent on both a conscious signal native the mind and the firing rate of sensory stretch yarn from the bladder and urethra. At short bladder volumes, the afferent firing of the stretch receptor is low, and also results in relaxation of the bladder. At high bladder volumes, the afferent firing of the stretch receptor increases, and also causes a mindful sensation that urinary urge. This urge becomes stronger as the bladder becomes an ext full.

The micturition reflex reasons bladder contraction throughout voiding, through a neural pathway. This reflex may lead to involuntary micturition in people that might not have the ability to feel the emotion of urinary urge, due to the shooting of the stretch receptors themselves.


Waste management in various other Body Systems

In addition to the kidneys, the liver, skin, and also lungs additionally have vital roles in the excretion of waste from the body.


Key Takeaways

Key PointsThe lungs, liver, and also skin room the key non- renal device organs involved in waste excretion.The liver is a an important organ v a wide selection of functions, including detoxification, protein synthesis, and also the manufacturing of the biochemicals important for digestion.The liver counter waste into other substances, yet does not remove it native the human body directly.The skin has actually sweat glands the secrete a fluid waste referred to as perspiration, or sweat, i beg your pardon is a pathway because that water and also ion removal from the body, amongst other things.The lung diffuse gas wastes, such as carbon dioxide, from the bloodstream as a normal component of respiration.Key Termsbilirubin: A bile pigment the is a product the the breakdown of the heme part of hemoglobin, the is processed right into bile by the liver.urea: A water-soluble organic compound, CO(NH2)2, developed by the management of proteins and also excreted in the urine. The liver counter ammonia to urea.

Besides the renal system, many other organs and also body systems are directly connected in the excretion of waste products. These other systems room responsible because that the removed of the waste assets of the metabolism, as well as other liquid and also gaseous wastes, yet also carry out other an essential functions.


The lungs: The lungs space responsible because that the removed of gas waste native the body.


Similar come renal clearance, these various other organs have a clearance price of your own, and also forms a component of complete body clearance. The skin, lungs, and liver are the main waste removal organs external of the non-renal system; however, their ability to remove wastes is normally less 보다 that of the renal system.

Liver rubbish Removal

The liver has many vital functions, consisting of a role in digestion, protein synthesis, and nutrient and vitamin storage. The liver also plays crucial function in the management of body waste. The acts as a detoxification system for the body, processing and neutralizing drugs and also toxins.

The liver is connected in the malfunction and recycling of red blood cells, consisting of the remove of bilirubin native the body by secreting it into the bile, which then features as a fat emulsifier in the cradle system.

Additionally, the liver is connected in the removal of toxicity ammonia native the body by converting it to non-toxic urea, which is climate excreted by the kidneys and also put right into urine throughout tubular secretion. If the liver may break down or neutralize waste in a different and safer kind for the body, the doesn’t straight remove the waste from the body.

Skin garbage Removal

Skin has actually sweat glands the secrete a liquid waste called perspiration. Perspiration, or sweat, is a liquid consisting generally of water, and various dissolved solid wastes, the is excreted through the sweat glands. The sweat glands remove a little of overabundance water and also salts, and also serve the duty of cooling the body throughout thermoregulation.

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Respiratory waste Removal

The lungs are responsible because that the remove of gas waste native the body. Carbon dioxide is a toxic byproduct of cellular respiration. The lungs eliminate carbon dioxide from the bloodstream during ventilation, trading it because that oxygen. This duty is essentially vital for regulating blood pH, because blood mountain is directly related come the concentration the carbon dioxide liquified in carbonic mountain in the blood stream. Excreting much more carbon dioxide waste will mitigate the mountain of blood.