Pelvis-4: Urinary bladder & Urethra

Summary

This video provides an in-depth anatomical overview of the male pelvic region, focusing on the bladder and urethra. Key structures include the bladder’s apex, base, and internal trigone, with its relationships to surrounding organs like the prostate and seminal vesicles. The transcript explores the different segments of the urethra, such as the pre-prostatic, prostatic, bulbous, and penile parts, along with their anatomical features. It also compares the male urethra with the shorter female urethra. The video offers valuable insights into the bladder’s mucosa and its folds, as well as important features of the prostate gland and urethra.

Takeaways

• 😀 The sagittal section of the male pelvis reveals key structures, including the bladder, urethra, and prostate gland.
• 😀 The bladder's apex is attached to the median ligament, and the base is related to the seminal vesicles and vas deferens.
• 😀 The superior surface of the bladder is covered by the peritoneum, which extends onto the rectum.
• 😀 The internal trigone, found on the posterior surface of the bladder, is a smooth region bounded by the ureter openings and internal urethral meatus.
• 😀 The mucosa of the bladder is loosely attached to the submucosa except at the internal trigone, where it adheres firmly.
• 😀 The urethra begins at the internal urethral meatus and is divided into several parts: pre-prostatic, prostatic, membranous, and penile.
• 😀 The pre-prostatic part of the urethra extends from the bladder neck to the base of the prostate.
• 😀 The prostatic urethra passes through the prostate gland and contains Bartholin's gland.
• 😀 The membranous part of the urethra passes through the urogenital diaphragm.
• 😀 The penile (spongy) part of the urethra includes the bulbous fossa and dilatation at the glans penis.
• 😀 The peritoneum's reflection onto the rectum forms the rectovesical pouch, located near the bladder.

Q & A

What is the role of the peritoneum in relation to the bladder and rectum?

The peritoneum covers the superior surface of the bladder and is reflected onto the anterior surface of the rectum, forming a structure known as the rectovesical pouch.

What is the internal trigone of the bladder, and how is it formed?

The internal trigone is a triangular area on the posterior surface of the bladder, formed by the ureteric orifices and the internal urethral meatus. It is characterized by its mucosa, which is firmly adhered to the muscle layer.

How is the mucosa of the bladder different from other regions?

The mucosa of the bladder is loosely attached to the submucosa, except in the posterior surface where it is firmly adhered to the muscle layer, forming the internal trigone.

What is the significance of the prostate gland in relation to the bladder?

The prostate gland surrounds the neck of the bladder and plays a role in the function of the male reproductive system, especially in relation to the prostatic urethra.

Can you describe the structure of the male urethra?

The male urethra has different parts: the pre-prostatic part, the prostatic urethra, the membranous part passing through the urogenital diaphragm, and the penile part, which includes the bulbous and spongy sections.

What is Barrow's montanum, and where is it located?

Barrow's montanum is a median elevation found in the prostatic urethra. It is located between the openings of the ejaculatory ducts.

What are the main functions of the internal urethral meatus?

The internal urethral meatus serves as the opening from the bladder into the urethra. It marks the point where urine flows from the bladder into the urethral system.

How does the structure of the female urethra differ from the male urethra?

The female urethra is shorter, about 4 centimeters long, and extends from the internal urethral meatus to the external urethral meatus, whereas the male urethra is longer and passes through different parts such as the prostate.

What is the function of the seminal vesicle and vas deferens in relation to the bladder?

The seminal vesicle and vas deferens are located near the base of the bladder and play important roles in male reproduction by transporting semen during ejaculation.

What is the importance of the bulbourethral fossa in the male reproductive system?

The bulbourethral fossa is located in the penile part of the urethra, and it plays a role in secreting fluids that lubricate the urethra during sexual activity.