Chapter 23 - Section 23.7 - Study Guide - Assess Your Learning Outcomes - Page 922: 3

The female urethra and external urethral sphincter are important structures involved in the urinary system, specifically in the process of urination. Here's an overview of the anatomy of the female urethra and external urethral sphincter: **Female Urethra**: The female urethra is a tubular structure that serves as a conduit for the passage of urine from the urinary bladder to the external environment. It is shorter than the male urethra and has a different anatomical relationship with other structures. The female urethra can be divided into two main portions: the proximal (internal) urethra and the distal (external) urethra. 1. **Proximal (Internal) Urethra**: - The proximal portion of the female urethra is located within the pelvis, surrounded by the muscles of the pelvic floor. - It begins at the neck of the urinary bladder and extends through the pelvic floor muscles. 2. **Distal (External) Urethra**: - The distal portion of the female urethra is located in the perineum, the area between the vagina and the anus. - It passes through the external urethral sphincter and opens to the outside at the external urethral orifice. **External Urethral Sphincter**: The external urethral sphincter is a voluntary skeletal muscle that surrounds the distal part of the urethra. It plays a crucial role in maintaining urinary continence, allowing us to voluntarily control the initiation and inhibition of urination. 1. **Location and Structure**: - The external urethral sphincter surrounds the urethra as it passes through the perineum. - It consists of voluntary skeletal muscle fibers that are under conscious control. 2. **Function**: - The external urethral sphincter contracts to keep the urethra closed, preventing the involuntary release of urine. - During urination, the conscious relaxation of the external urethral sphincter allows urine to flow out of the urethra. 3. **Innervation**: - The external urethral sphincter is innervated by somatic motor nerves from the pudendal nerve, which arises from the sacral spinal cord. - This innervation allows for voluntary control over the muscle's contraction and relaxation. Together, the female urethra and external urethral sphincter work in coordination to control the release of urine from the bladder. The external urethral sphincter allows for voluntary initiation and inhibition of urination, contributing to the body's ability to regulate when and where urination occurs.

The female urethra and external urethral sphincter are important structures involved in the urinary system, specifically in the process of urination. Here's an overview of the anatomy of the female urethra and external urethral sphincter: **Female Urethra**: The female urethra is a tubular structure that serves as a conduit for the passage of urine from the urinary bladder to the external environment. It is shorter than the male urethra and has a different anatomical relationship with other structures. The female urethra can be divided into two main portions: the proximal (internal) urethra and the distal (external) urethra. 1. **Proximal (Internal) Urethra**: - The proximal portion of the female urethra is located within the pelvis, surrounded by the muscles of the pelvic floor. - It begins at the neck of the urinary bladder and extends through the pelvic floor muscles. 2. **Distal (External) Urethra**: - The distal portion of the female urethra is located in the perineum, the area between the vagina and the anus. - It passes through the external urethral sphincter and opens to the outside at the external urethral orifice. **External Urethral Sphincter**: The external urethral sphincter is a voluntary skeletal muscle that surrounds the distal part of the urethra. It plays a crucial role in maintaining urinary continence, allowing us to voluntarily control the initiation and inhibition of urination. 1. **Location and Structure**: - The external urethral sphincter surrounds the urethra as it passes through the perineum. - It consists of voluntary skeletal muscle fibers that are under conscious control. 2. **Function**: - The external urethral sphincter contracts to keep the urethra closed, preventing the involuntary release of urine. - During urination, the conscious relaxation of the external urethral sphincter allows urine to flow out of the urethra. 3. **Innervation**: - The external urethral sphincter is innervated by somatic motor nerves from the pudendal nerve, which arises from the sacral spinal cord. - This innervation allows for voluntary control over the muscle's contraction and relaxation. Together, the female urethra and external urethral sphincter work in coordination to control the release of urine from the bladder. The external urethral sphincter allows for voluntary initiation and inhibition of urination, contributing to the body's ability to regulate when and where urination occurs.