ANATOMY

Detailed explanation-1: -The internal urethral sphincter regulates involuntary control of urine flow from the bladder to the urethra, and the external urethral sphincter provides voluntary control of urine flow from the bladder to the urethra.

Detailed explanation-2: -The internal sphincter of the urinary bladder is under involuntary control whereas the external sphincter is under voluntary control.

Detailed explanation-3: -The internal sphincter is a continuation of the detrusor muscle and is made of smooth muscle, therefore it is under involuntary or autonomic control.

Detailed explanation-4: -It is located at the junction of the urethra with the urinary bladder and is continuous with the detrusor muscle, but anatomically and functionally fully independent from it. It is composed of smooth muscle, so it is under the control of the autonomic nervous system, specifically the sympathetic nervous system.

Detailed explanation-5: -The external anal sphincter is composed of skeletal muscle that functions like other postural muscles in the body. It is a voluntary muscle that responds to volitional commands to contract and maintain continence when feces are propelled through a relaxed internal anal sphincter into the rectum.