Final answer:
The empty urinary bladder resembles an upside-down pear shape, with its epithelial lining able to change from a columnar to a squamous appearance as it fills. The option (A) is correct.
Step-by-step explanation:
When empty, the urinary bladder exhibits an upside-down pear shape. The bladder is a highly distensible organ made up of the detrusor muscle and lined with transitional cellular epithelium. This epithelium is unique because it can change shape depending on how much urine is in the bladder.
When the bladder is empty, the epithelium appears similar to columnar cells, but as it stretches, it transitions to a squamous appearance, suggesting that the epithelial lining unfolds and becomes thinner as the bladder fills. Therefore, option (A) is correct.
This question is not complete, Here I am attaching the complete question:
When empty, the urinary bladder exhibits an upside-down _______ shape.
A) Pear
B) Oval
C) Spherical
D) Teardrop