What are the deep folds of the stomach and urinary bladder that allow these organs to expand called? A. Villi B. Muscularis C. Lumen D. Rugae

Break Down the Problem

1. Identify the main question regarding the anatomical features of the stomach and urinary bladder.
2. Determine which option describes the deep folds that allow these organs to expand.

Relevant Concepts

• Rugae are the folds in the lining of the stomach and bladder that enable expansion.
• Other options (Villi, Muscularis, Lumen) refer to different anatomical features.

Analysis and Detail

1. Villi: These are tiny, finger-like projections found in the intestines that increase surface area for absorption.
2. Muscularis: This term refers to the muscle layer within the wall of the gastrointestinal tract or bladder.
3. Lumen: This is the hollow part of an organ, such as the cavity inside the stomach or urinary bladder; it does not pertain to folds.
4. Rugae: These are indeed the folds of the stomach lining that allow the stomach to expand when filled with food or liquid.

Verify and Summarize

• After analyzing each option, it is clear that the correct answer is associated with the folds that allow expansion in the stomach and bladder.

Final Answer

The correct answer is D. Rugae.