Kidney stone disease originating anywhere in the urinary system, including the kidneys and bladder. Nephrolithiasis refers to the presence of such stones in the kidneys. Calyceal calculi are aggregations in either the minor or major calyx, parts of the kidney that pass urine into the ureter (the tube connecting the kidneys to the urinary bladder). The condition is called ureterolithiasis when a calculus is located in the ureter. Stones may also form or pass into the bladder, a condition referred to as bladder stones. Stones less than in diameter pass spontaneously in up to 98% of cases, while those measuring in diameter pass
Urinary bladder that protects the cells beneath it from urine, the urothelium (a form of transitional epithelium), a basement membrane, and the lamina propria. The mucosal lining also offers a urothelial barrier against the passing of infections. The detrusor muscle is a layer of the urinary bladder wall made of smooth muscle fibers arranged in spiral, longitudinal, and circular bundles. Stretch receptors in the bladder signal the parasympathetic nervous system to stimulate the muscarinic receptors in the detrusor to contract the muscle when the bladder is extended. This encourages the bladder to expel urine through the urethra. The main receptor activated is