Contraction and expansion of intestinal wall involuntarily is a perfect example of physiological description rather than an anatomical description.
Anatomical description of an object or an organism is defined as the study of internal organs and their properties. where is physiological description deals with the outer and physical description of an organism or thing.
For a physiological description one has not to cut the organism to study the internal organs. In the case of intestinal wall expansion and contraction it can be seen physically from outside but it is a function of internal organ therefore it is a physiological description rather than an anatomical description
