Anatomi Systema Uropoetica : Vesica urinaria et Urethra

Summary

This video script introduces the anatomy of the uropoietic system, specifically focusing on the bladder (vesica urinaria) and urethra. The presenter, Reza Baskoro, provides an in-depth explanation of the bladder’s structure, function, and anatomical positioning in both males and females. He describes various layers of the bladder, its internal components, and the processes involved in urination. The presentation also covers vascularization, innervation, and clinical conditions affecting the uropoietic system, including common diseases and surgical treatments. The educational content is designed for medical students, offering a comprehensive understanding of the urinary system.

Takeaways

• 😀 Vesica urinaria is a muscular, membranous sac that functions as a storage for urine. It changes shape based on fullness, being oval when full and flattened when empty.
• 😀 The position of vesica urinaria differs between infants and adults. In adults, its location varies slightly between males and females, with females having it positioned lower.
• 😀 The anatomical parts of the vesica urinaria include the apex, base, superior and inferior faces, and collum vesicae, each with distinct characteristics and relationships to surrounding structures.
• 😀 The internal structure of vesica urinaria includes four layers: Tunica serosa, Tunica muscularis, Tunica submucosa, and Tunica mucosa. The muscle layers form the detrusor muscle.
• 😀 The mucosa of the vesica urinaria forms folds when empty but flattens out when full. The trigone area, especially at the base, plays an important role in the function of the organ.
• 😀 The reflex for urination begins when the bladder reaches around 300ml of urine. Sensory impulses travel to the brain, triggering the urge to urinate.
• 😀 The vascularization of vesica urinaria is supported by three main arteries: superior, media, and inferior vesical arteries, which are branches of the internal iliac artery.
• 😀 The innervation of vesica urinaria involves both sympathetic and parasympathetic fibers, with the sympathetic fibers inhibiting detrusor contraction and parasympathetic fibers promoting it.
• 😀 Urethra serves as the conduit for urine and semen. It is differentiated between males and females, with the male urethra being significantly longer and serving both urine and semen.
• 😀 The male urethra has distinct segments: pars prostatica, pars membranacea, and pars spongiosa, each with its unique structure and function, including glands like the bulbourethral gland.
• 😀 The female urethra is shorter (about 4 cm) and more susceptible to infections due to its proximity to the vagina and anus. It has its own unique set of glands like the paraurethral glands.
• 😀 Clinical conditions related to the urethra include ruptures due to trauma and procedures like transurethral resection of the prostate (TURP) for benign prostatic hyperplasia (BPH).

Q & A

What is the primary function of the vesica urinaria?

The vesica urinaria, or urinary bladder, serves as a muscular, membranous sac that temporarily stores urine until it is excreted from the body.

How does the shape of the vesica urinaria change depending on its fullness?

When the vesica urinaria is empty, it appears flat with four sides, and when it is full, it becomes oval-shaped and can hold up to 500 ml of urine.

Where is the vesica urinaria located in adults compared to babies?

In babies, the vesica urinaria is positioned higher than in adults, where it is typically located at the level of the upper edge of the symphysis pubis.

What are the main anatomical regions of the vesica urinaria?

The vesica urinaria has several regions, including the apex, the posterior surface (facies posterior), the superior surface (facies superior), the lateral surfaces, and the neck (collum vesicae).

What are the internal structural layers of the vesica urinaria?

The vesica urinaria has four internal structural layers: the tunica serosa, tunica muscularis (which forms the detrusor muscle), tunica submucosa, and tunica mucosa.

What is the role of the osteum uretralis in the vesica urinaria?

The osteum uretralis is the opening at the superior angle of the trigone of the vesica urinaria, which serves as the entrance for urine from the ureter.

What happens when the vesica urinaria fills with urine in terms of positioning?

When filled, the superior surface of the vesica urinaria rises, potentially entering the abdominal cavity, while the posterior and neck portions remain relatively stable.

How does the reflex to urinate work when the vesica urinaria fills?

As the vesica urinaria fills and reaches around 300 ml, it sends afferent impulses to the brain, signaling the need to urinate. Efferent impulses then trigger detrusor muscle contraction and relaxation of the sphincters.

What is the function of the nervous system in urination regulation?

The nervous system, through both sympathetic and parasympathetic fibers, helps regulate urination by controlling the detrusor muscle and sphincters, either promoting or inhibiting urination depending on the situation.

What is the difference between the male and female urethra in terms of length and function?

The male urethra is about 18-20 cm long and carries both urine and semen, whereas the female urethra is shorter, about 4 cm long, and only carries urine.