Functies van gladde spieren

Smooth muscles facilitate the involuntary movements of internal organs, such as the movement of food through the gut or the regulation of blood flow.

All hollow organs, except the heart, largely comprise visceral smooth muscle tissue organized into layers of tightly packed fibers connected by gap junctions, allowing contraction as a single unit.

For instance, visceral muscle in the intestinal walls is arranged in longitudinal layers along the length and circular layers around the circumference.

The contraction of longitudinal layers shortens the intestinal length, while the circular layers facilitate constriction of the inner cavity.

By alternately contracting and relaxing, these layers facilitate the mixing of substances in the cavity and their movement through the intestinal passage.

However, organs such as the eye and walls of large arteries have multi-unit smooth muscle fibers with individual nerve endings which stimulate specific areas of the organ.

For example, multi-unit smooth muscles in large pulmonary arteries regulate their lumen diameter to precisely redirect blood to well-ventilated lung regions, allowing enhanced oxygenation based on physiological demands.