Final answer:
Smooth muscle tissue is typically organized into two layers, known as single-unit and multiunit smooth muscle.
Step-by-step explanation:
In the human body, smooth muscle tissue is typically arranged in two layers when it occurs in the walls of hollow organs and passages. These two arrangements are known as single-unit and multiunit smooth muscle.
The more commonly found single-unit type has its muscle fibers connected through gap junctions, allowing the muscle to contract as a cohesive unit.
Multiunit smooth muscle cells are not electrically coupled through gap junctions, as such, they depend on autonomic nerves or hormones for stimuli, and these cells are found around large blood vessels, in respiratory airways, and in the eyes.
Single-unit smooth muscle is prevalent in the walls of visceral organs such as the intestines, stomach, and urinary bladder, and in pathways including the respiratory and circulatory systems. This type is essential for the gradual and rhythmic contractions that facilitate the passage of substances through the body.
It possesses the ability to stretch and maintain tension even as the organ's size changes, which is critical for continuous functioning.
It is important to note that smooth muscle cells are spindle-shaped, tapering at both ends, and contain a single nucleus. The arrangement of smooth muscle ensures effective functioning throughout various systems by maintaining organ size and contractility.
Muscle tone is preserved even as organs expand and contract, which is particularly important for functions such as digestion and urinary retention.