What is the structure and function of smooth muscle?
Smooth muscle is a type of muscle tissue which is used by various systems to apply pressure to vessels and organs. Smooth muscle is composed of sheets or strands of smooth muscle cells. These cells have fibers of actin and myosin which run through the cell and are supported by a framework of other proteins.
Are smooth muscle simple in structure?
The smooth muscle cell is 3-10 µm thick and 20-200 µm long. As opposed to skeletal muscle fibers these bundles do not run strictly parallel and ordered but consist in a complex system. Thus the cells can contract much stronger than striated musculature.
What are the characteristics of smooth muscle?
Four characteristics define smooth muscle tissue cells: they are involuntarily controlled, not striated, not branched, and singly nucleated. The unconscious regions of the brain control visceral muscle through the autonomic and enteric nervous systems.
What are the 5 characteristics of smooth muscle?
Smooth Muscle Characteristics
- Smooth muscle cell shape. The smooth muscle cell is fusiform in shape.
- The filaments.
- Single nucleus.
- Elasticity.
- Contractility.
- Lack of sarcomeres.
- Lack of a tropomyosin complex.
What is the shape of smooth muscle cells?
Smooth muscle cells are spindle shaped, have a single, centrally located nucleus, and lack striations.
What is one function of the smooth muscle?
The primary function of smooth muscle is contraction. Smooth muscle consists of two types: single-unit and multi-unit. Single-unit smooth muscle consists of multiple cells connected through connexins that can become stimulated in a synchronous pattern from only one synaptic input.
Where is smooth muscle found in the body?
Smooth muscle fibers are located in walls of hollow visceral organs (such as the liver, pancreas, and intestines), except the heart, appear spindle-shaped, and are also under involuntary control. Skeletal muscle fibers occur in muscles which are attached to the skeleton.
What are the 3 characteristics of smooth muscle?
Smooth muscle is typically non-striated, uni-nucleated, and involuntary or reflexive. This muscle type is slow twitch and often rhythmic in contraction.
What are three functions of smooth muscles?
For simplicity, the basic functions of smooth muscle in the organ systems appear listed below.
- Gastrointestinal tract – propulsion of the food bolus.
- Cardiovascular – regulation of blood flow and pressure via vascular resistance.
- Renal – regulation of urine flow.
- Genital – contractions during pregnancy, propulsion of sperm.
Which of the following body parts has smooth muscles?
Smooth muscle (so-named because the cells do not have striations) is present in the walls of hollow organs like the urinary bladder, uterus, stomach, intestines, and in the walls of passageways, such as the arteries and veins of the circulatory system, and the tracts of the respiratory, urinary, and reproductive …