During relaxation, which statement describes distal intraluminal pressure?

During relaxation, which statement describes distal intraluminal pressure?

• A. Distal intraluminal pressure is reduced
• B. Distal intraluminal pressure increases
• C. Distal intraluminal pressure remains unchanged
• D. Distal intraluminal pressure is eliminated

Answer: (A)

When a segment of a tubular organ relaxes, its circular smooth muscle tone decreases, causing the lumen to dilate and the wall to become more compliant. This reduced tone lowers the resistance to flow and lessens the force pushing against the distal segment. As a result, the pressure measured distal to the relaxing area falls. In short, relaxation reduces distal intraluminal pressure because the lumen expands and offers less resistance to contents moving forward.

When a segment of a tubular organ relaxes, its circular smooth muscle tone decreases, causing the lumen to dilate and the wall to become more compliant. This reduced tone lowers the resistance to flow and lessens the force pushing against the distal segment. As a result, the pressure measured distal to the relaxing area falls. In short, relaxation reduces distal intraluminal pressure because the lumen expands and offers less resistance to contents moving forward.