Vescica

Vescica is the term used in Latin and in several Romance languages to refer to the urinary bladder. In English, the organ is usually called the urinary bladder, with vesica urinaria used in anatomical nomenclature. The word vesica means a bladder or sac.

Anatomy and structure: In humans, the bladder is a hollow, muscular organ located in the pelvic cavity. Its inner lining is a transitional epithelium that forms folds (rugae) when the bladder is empty. The detrusor muscle, a thick layer of smooth muscle, contracts to expel urine. Anterior to the bladder is the pubic bone, and the bladder connects to the ureters at the ureteric orifices and to the urethra at the bladder neck, forming the trigone region. Blood supply comes mainly from vesical arteries, and innervation includes parasympathetic fibers from the pelvic nerves (promoting contraction) and sympathetic fibers (modulating storage). Motor control of the external urethral sphincter is provided by the somatic pudendal nerve.

Function and physiology: The bladder stores urine at low pressure and expands as it fills. The sensory system signals fullness, triggering the micturition reflex when appropriate. Voiding involves coordinated detrusor contraction and relaxation of the internal and external sphincters, with voluntary control via the somatic nervous system.

Clinical significance: Common conditions affecting the vesica include cystitis (inflammation or infection), overactive bladder, urinary incontinence, bladder cancer (often urothelial/transitional cell carcinoma), and urinary retention or bladder stones. Diagnosis relies on urinalysis, imaging (ultrasound, CT), and cystoscopy, while treatment ranges from behavioral approaches and medications to surgical interventions in selected cases. Developmentally, the bladder arises from the urogenital sinus, with the mucosa derived from endoderm and the muscular wall from smooth muscle tissue.