Bladder Detrusor Muscle Contraction During Urination - Medical Illustration #3314944 (License: Personal Use)

This anatomical illustration depicts the urinary bladder in cross-section, highlighting the smooth muscle layer known as the detrusor muscle (pink outer layer). Black downward arrows show coordinated contraction of this muscle during micturition, compressing the bladder lumen (yellow fluid) and forcing urine into the urethra below. The external urethral sphincter (red band) is shown relaxed to allow flow.

Used in urology educational materials, patient brochures on urinary incontinence or voiding dysfunction, and medical textbooks to explain normal micturition physiology. Matches user intent for understanding bladder function, neurogenic bladder, or overactive bladder mechanisms.