Maximus Gage
The urethra is a fibrous and muscular tube which connects the urinary bladder to the external urethral meatus. It is surrounded by two urethral sphincters, the external and internal urethral sphincters, which are muscles that control the exit of urine from the bladder. When these muscles contract, the urethra narrows, and urination stops or slows. The external urethral sphincter is a striated muscle that allows voluntary control over urination, while the internal sphincter is formed by the involuntary smooth muscles lining the bladder neck and urethra.
| Characteristics | Values |
|---|---|
| Urethral sphincters | Two muscles used to control the exit of urine in the urinary bladder through the urethra |
| External urethral sphincter | Striated muscle that allows voluntary control over urination |
| Internal urethral sphincter | Involuntary smooth muscles lining the bladder neck and urethra |
| Internal urethral sphincter location | Located at the bladder's inferior end and the urethra's proximal end at the junction of the urethra with the urinary bladder |
| External urethral sphincter location | Originates at the ischiopubic ramus and inserts into the intermeshing muscle fibres from the other side |
| External urethral sphincter nerve control | Controlled by the deep perineal branch of the pudendal nerve |
| Internal urethral sphincter nerve control | Controlled by the sympathetic division of the autonomic nervous system |
Explore related products
What You'll Learn
The urethra is a fibrous and muscular tube
The urethra's smooth muscle cells are mechanically coupled to each other to coordinate mechanical force and electrical signalling in an organised, unitary fashion. During urination, the smooth muscle lining the urethra relaxes in concert with bladder contractions to forcefully expel the urine in a pressurised stream. Following this, the urethra re-establishes muscle tone by contracting the smooth muscle layer, and the bladder returns to a relaxed, quiescent state.
The Muscular Makeup of Our Feet and Toes
You may want to see also
Explore related products
The external urethral sphincter is a striated muscle
The urethra is a fibrous and muscular tube that connects the urinary bladder to the external urethral meatus. It is used to control the exit of urine from the bladder. The urethra has two muscles: the external urethral sphincter and the internal urethral sphincter. The external urethral sphincter is a striated muscle that allows voluntary control over urination. It originates at the ischiopubic ramus and inserts into the intermeshing muscle fibres from the other side. It is controlled by the deep perineal branch of the pudendal nerve. The internal urethral sphincter, on the other hand, is formed by the involuntary smooth muscles lining the bladder neck and urethra. It is present in both males and females.
The external urethral sphincter is composed of skeletal muscle. When it contracts, the urethra narrows, and urination slows or stops. The internal urethral sphincter is also important in maintaining continence during bladder filling and facilitating urine flow during voiding. The disruption of this complex activity can have profound consequences on normal lower urinary tract function during the micturition cycle.
The urethra is longer in males than in females because it passes through the penis in males. In human males, the urethra is on average 18 to 20 centimetres (7 to 8 inches) long and opens at the end of the external urethral meatus. The male urethra is also the conduit for semen during orgasm.
The Colon's Muscular Power: Understanding Its Role
You may want to see also
Explore related products
The internal sphincter is formed by involuntary smooth muscles
The urethra is a fibrous and muscular tube which connects the urinary bladder to the external urethral meatus. It is used to control the exit of urine from the bladder. The urethra has two sphincters, the external and internal urethral sphincters.
The smooth muscles of the internal sphincter relax during urination, allowing urine to pass through the urethra. After urination, the smooth muscles contract to re-establish muscle tone, and the bladder returns to a relaxed, quiescent state.
The internal sphincter is crucial for maintaining continence during bladder filling and facilitating urine flow during voiding. Disruptions to the internal sphincter's function can have profound consequences on normal lower urinary tract function during the micturition cycle.
The Ankle's Muscular Mystery: Exploring Ankle Anatomy
You may want to see also
Explore related products
The urethral sphincter regulates the outflow of urine
The urethra is a fibrous and muscular tube which connects the urinary bladder to the external urethral meatus. The urethral sphincter is a muscular structure that regulates the outflow of urine from the bladder into the urethra. There are two urethral sphincters, the external and internal urethral sphincters. When these muscles contract, the urethra narrows, and urination stops or slows. The external urethral sphincter is a striated muscle that allows voluntary control over urination. The internal sphincter, formed by the involuntary smooth muscles lining the bladder neck and urethra, receives its nerve supply by the sympathetic division of the autonomic nervous system. The internal sphincter is present in both males and females.
The external urethral sphincter originates at the ischiopubic ramus and inserts into the intermeshing muscle fibres from the other side. It is controlled by the deep perineal branch of the pudendal nerve. Activity in the nerve fibres constricts the urethra. The internal sphincter muscle of the urethra is located at the bladder's inferior end and the urethra's proximal end at the junction of the urethra with the urinary bladder.
The smooth muscle lining the urethra relaxes during urination, in concert with bladder contractions, to forcefully expel the urine in a pressurised stream. Following this, the urethra re-establishes muscle tone by contracting the smooth muscle layer, and the bladder returns to a relaxed, quiescent state.
Elliptical Workouts: Burning Fat, Not Muscle
You may want to see also
Explore related products
The urethra is the vessel through which urine passes
The urethra has two muscles, the external and internal urethral sphincters, which control the exit of urine from the bladder. When these muscles contract, the urethra narrows, and urination stops or slows. The external urethral sphincter is a striated muscle that allows voluntary control over urination. The internal sphincter, formed by the involuntary smooth muscles lining the bladder neck and urethra, receives its nerve supply by the sympathetic division of the autonomic nervous system. The internal sphincter is present in both males and females.
During urination, the smooth muscle lining the urethra relaxes in concert with bladder contractions to forcefully expel the urine in a pressurised stream. Following this, the urethra re-establishes muscle tone by contracting the smooth muscle layer, and the bladder returns to a relaxed, quiescent state.
Exploring the Jaw: Muscles and Their Functions
You may want to see also
Frequently asked questions
Yes, the urethra is a fibrous and muscular tube which connects the urinary bladder to the external urethral meatus.
The muscles in the urethra are called the urethral sphincters. There are two of these: the external urethral sphincter and the internal urethral sphincter.
The urethral sphincters control the exit of urine from the bladder through the urethra. When the muscles contract, the urethra narrows and urination stops or slows.
