Smooth muscle tissue

A type of involuntary muscle that plays a critical role in various organ systems throughout the body.

Smooth muscle tissue is a form of non-striated muscle found in various internal structures. Unlike skeletal muscle, smooth muscle is not under voluntary control and is responsible for involuntary movements. This tissue is characterized by elongated, spindle-shaped cells that lack the striations seen in skeletal muscle, giving it a smooth appearance.

Terminologia Anatomica

tissue-musculi-smooth

System

Muscular system

Function

The primary function of smooth muscle tissue is to facilitate involuntary movements within various organ systems, such as the digestive, respiratory, and circulatory systems. In the digestive tract, smooth muscle contracts rhythmically to propel food through peristalsis, aiding in digestion and absorption. In blood vessels, it regulates blood flow by constricting and dilating the vessels, influencing blood pressure. Additionally, smooth muscle tissue plays a crucial role in the implementation of reflex actions, such as the contraction of the iris in response to changes in light levels. Overall, smooth muscle's involuntary nature allows it to maintain essential bodily functions without conscious effort, underpinning the efficiency and regulation of critical physiological processes.

Location

Smooth muscle tissue is located in various visceral organs throughout the body. It can be found lining the walls of hollow organs such as the stomach, intestines, bladder, and blood vessels. In the gastrointestinal tract, smooth muscle forms two main layers: an inner circular layer and an outer longitudinal layer, working in tandem to facilitate the movement of contents. Furthermore, smooth muscle is present in the uterus, where it plays a vital role during childbirth by enabling contractions. Overall, the widespread presence of smooth muscle tissue is integral to the functionality of numerous organ systems, allowing them to operate seamlessly in maintaining homeostasis.

Did You Know?

Smooth muscle can sustain contractions for extended periods without fatigue, allowing organs like the bladder to hold urine until ready to release.
Unlike other muscle types, smooth muscle can regenerate and adapt more readily in response to demands, making it unique in tissue repair.
Smooth muscle tissue accounts for approximately 10% of the total muscle mass in the human body.