The affected kidney could then develop hydronephrosis, should a part of the kidney become swollen due to blocked flow of urine. Kidney stones are very common and are usually clumps of aggregated minerals that are most often found at the constriction points in the ureter. Ureter cancer is often due to a malignant transformation of of the transitional epithelial tissue, which is more vulnerable to developing cancer cells compared to other tissues. The urinary bladder is a hollow, muscular, and distendible or elastic organ that sits on the pelvic floor.
The urinary bladder is a urine storage organ that is a part of the urinary tract. The bladder is a hollow, muscular, and elastic organ that sits on the pelvic floor. The bladder expands and fills with urine before it is discharged into the urethra during urination.
The bladder is a hollow, sac-like organ made of transitional epithelium, similar to the ureter that feeds into it. The ureters enter the bladder diagonally from its dorsolateral floor in an area called the trigone, which is a triangle-shaped anatomical region. The urethra exits at the lowest point of the triangle of the trigone.
There are two sphincters, or muscular valves, that separate the bladder from the urethra. The sphincters must open before the urine can flow into the urethra. The internal sphincter is under involuntary control and the external sphincter is under voluntary control.
The urinary bladder : The urinary bladder is composed of several layers of tissue that facilitate urine storage and expulsion. The associated structures of the urinary and male reproductive tract are labelled. When the bladder fills with urine stretch receptors send nerve impulses to the spinal cord, which then sends a reflex nerve impulse back to the internal sphincter valve at the neck of the bladder that causes it to relax and allow the flow of urine into the urethra.
The internal urethral sphincter is involuntary and controlled by the autonomic nerves. The bladder has a minor temperature regulation function since some heat may leave the body in the form of urine.
A normal bladder empties completely upon a complete discharge, otherwise it is a sign that its elasticity is compromised; when it becomes completely void of fluid, it may cause a chilling sensation due to the rapid change of body temperature. The urinary bladder usually holds — ml of urine. As urine accumulates, the walls of the bladder thin as it stretches, allowing the bladder to store larger amounts of urine without a significant rise in internal pressure of the bladder.
The bladder receives motor innervation from both sympathetic fibers, most of which arise from the hypogastric plexuses and nerves, and parasympathetic fibers, which come from the pelvic splanchnic nerves and the inferior hypogastric plexus. Sensation from the bladder is transmitted to the central nervous system CNS via general visceral afferent fibers. The urethra is a muscular tube that connects the bladder with the outside of the body and removes urine from the body. The urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids from the body.
The external urethral sphincter is a striated muscle that allows voluntary control over urination by controlling the flow of urine from the bladder into the urethra. In females, the urethra is shorter relative to males, and emerges above the vaginal opening. Its lining is composed primarily of non-keratinized stratified squamous epithelium that becomes transitional near the bladder. The urethra consists of three layers of tissues:. The urethral sphincter separates the bladder from the urethra.
Somatic conscious innervation of the external urethral sphincter is supplied by the pudendal nerve, which allows the sphincter to open and close.
As the urethra is shorter in females relative to males, they are more vulnerable to bacterial urinary tract infections. In males, the urethra travels through the penis and carries semen as well as urine.
Semen does not flow through the bladder or the rest of the urinary tract, instead it is a fluid made of sperm cells and other fluids that passes through a few different glands from the testes to the urethra through the vas deferens. Micturition is the ejection of urine from the urinary bladder through the urethra to the outside of the body.
Micturition, also known as urination, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control.
In infants, elderly individuals, and those with neurological injury, urination may occur as an involuntary reflex. Physiologically, micturition involves the coordination of the central, autonomic, and somatic nervous systems. The brain centers that regulate urination include the pontine micturition center, the periaqueductal gray, and the cerebral cortex, which cause both involuntary and voluntary control over micturition.
In males, urine is ejected through the penis, and in females through the urethral opening. Due to sexual dimorphism, and the positions where the urethra ends, males and females often use different techniques for urination.
They control blood pressure and produce the hormone erythropoietin. This hormone controls red blood cell production in the bone marrow. The kidneys also control the acid-base balance and conserve fluids. Two kidneys. This pair of purplish-brown organs is located below the ribs toward the middle of the back.
Their function is to:. The kidneys remove urea from the blood through tiny filtering units called nephrons. Each nephron consists of a ball formed of small blood capillaries glomerulus and a small tube called a renal tubule. Urea, together with water and other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney.
For example, white blood cells in the urine can be a sign of an infection. Pee also is a way for your body to keep the right amount of water. Did you ever notice that if you drink a lot, you pee more and the pee is pale yellow?
That's because your body is getting rid of extra water and your pee has more water in it than usual. Let's talk more about how the kidneys filter blood. When blood goes through the kidneys, water and some of the other stuff that is in blood like protein, glucose, and other nutrients go back into the bloodstream, while the waste and excess stuff is taken out.
Urine is what is left behind. But what is it exactly? Once pee is produced, it travels from the kidney to the bladder, where it's stored until you need to go to the bathroom. The bladder expands as it fills; when it's full, nerve endings in the bladder wall send a message to the brain that you need to pee. When you're in the bathroom, ready to go, the bladder walls contract and the sphincter a ringlike muscle that guards the exit from the bladder to the urethra relaxes. The filtrate absorbed in the glomerulus flows through the renal tubule, where nutrients and water are reabsorbed into capillaries.
At the same time, waste ions and hydrogen ions pass from the capillaries into the renal tubule. This process is called secretion. The secreted ions combine with the remaining filtrate and become urine. The urine flows out of the nephron tubule into a collecting duct.
It passes out of the kidney through the renal pelvis, into the ureter, and down to the bladder. The nephrons of the kidneys process blood and create urine through a process of filtration, reabsorption, and secretion. Nitrogenous wastes excreted in urine include urea, creatinine, ammonia, and uric acid. Ions such as sodium, potassium, hydrogen, and calcium are also excreted. Download Nephrons Lab Activity.
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