MRCP UK EXAMINATIONS

Detailed explanation-1: -Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract.

Detailed explanation-2: -Circular muscle contraction increases esophageal pressure, and longitudinal muscle contraction increases esophageal wall thickness. Synchrony of contraction of the two muscle layers, under physiological conditions, assures a coordinated and concurrent increase in esophageal pressure and wall thickness.

Detailed explanation-3: -At a fixed axial location within the esophagus, longitudinal muscle contraction precedes circular muscle contraction, but longitudinal muscle maximally shortens coincident with maximum circular muscle contraction. Longitudinal muscle then relaxes, but more slowly than circular muscle.

Detailed explanation-4: -Muscularis propria (externa): smooth muscle layer. There are usually two layers; the inner layer is circular, and the outer layer is longitudinal. These layers of smooth muscle are used for peristalsis (rhythmic waves of contraction), to move food down through the gut.