The urinary bladder is:
a. Collapsible
b. Completely sealed
c. Anterior to the pubic symphysis
d. Surrounded by renal calculi
The correct answer and explanation is:
The correct answer is a. Collapsible.
The urinary bladder is a highly elastic, muscular organ that stores urine until it is excreted from the body. It is located in the pelvic cavity, posterior to the pubic symphysis, and is capable of expanding and collapsing as it fills and empties. This collapsibility is due to the bladder’s smooth muscle walls and the transitional epithelium lining the interior, which allows it to stretch and accommodate varying amounts of urine.
The bladder has a unique capacity to expand as it fills with urine, and when it reaches a certain volume, stretch receptors in its walls signal the brain, prompting the urge to urinate. When the bladder is empty, its walls collapse, and the shape becomes more spherical. As the bladder fills, the transitional epithelium stretches to allow for a large volume of urine to be stored without a significant increase in internal pressure, which is crucial for the organ’s function.
Contrary to the other options:
- b. Completely sealed is incorrect because the urinary bladder is not sealed in a way that would prevent it from filling or emptying; it is connected to the urethra through the ureter, and the internal sphincter regulates urine release.
- c. Anterior to the pubic symphysis is misleading, as the bladder is located posterior (behind) the pubic symphysis in the pelvic cavity.
- d. Surrounded by renal calculi is incorrect because renal calculi (kidney stones) form in the kidneys and are not located around the bladder, although they may travel down the ureters to the bladder if they are passed.
Thus, the bladder’s unique collapsible nature is essential to its function in urine storage and regulation.