Smooth muscle fibers are located in walls of hollow visceral organs, except the heart, appear spindle-shaped, and are also under involuntary control . Skeletal muscle fibers occur in muscles which are attached to the skeleton. They are striated in appearance and are under voluntary control.
Is smooth muscle contraction voluntary or involuntary?
Both cardiac and smooth muscle are involuntary while skeletal muscle is voluntary.
Why is smooth muscle involuntary?
Smooth muscle is not under voluntary control ; thus, it is called involuntary muscle. The triggers for smooth muscle contraction include hormones, neural stimulation by the ANS, and local factors. ... Also, visceral muscle in the walls of the hollow organs (except the heart) contains pacesetter cells.
Can smooth muscle be contracted voluntarily?
Smooth muscle is not under voluntary control ; thus, it is called involuntary muscle. The triggers for smooth muscle contraction include hormones, neural stimulation by the ANS, and local factors.
What are the two types of smooth muscle?
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.
What is another name for smooth muscle?
Smooth muscle, also called involuntary muscle , muscle that shows no cross stripes under microscopic magnification. It consists of narrow spindle-shaped cells with a single, centrally located nucleus. Smooth muscle tissue, unlike striated muscle, contracts slowly and automatically.
What is an example of smooth muscle?
Smooth Muscle Examples
They are found in the body’s hollow organs like the intestines , digestive tracts, urinary bladder, ureters, and the blood vessels of the circulating blood system. They are also found in the wall of the lungs and the reproductive system of both genders.
How is the smooth muscle controlled?
Smooth muscle cells distributed in the visceral organs are under the control of the autonomic nervous system , and contraction or relaxation of the muscle cells plays an important physiological role in the control of blood pressure, motility of the digestive, respiratory and urinary tracts and secretion.
How is cardiac muscle similar to smooth muscle?
The cardiac muscle cell has one central nucleus , like smooth muscle, but it also is striated, like skeletal muscle. The cardiac muscle cell is rectangular in shape. The contraction of cardiac muscle is involuntary, strong, and rhythmical.
What characteristic applies to 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. Thus, visceral muscle is involuntarily controlled.
What is the difference between multi unit smooth muscle and single unit smooth muscle?
Single-unit smooth muscle produces slow , steady contractions that allow substances, such as food in the digestive tract, to move through the body. Multi-unit smooth muscle, the second type of smooth muscle observed, are composed of cells that rarely possess gap junctions, and thus are not electrically coupled.
Which hormone is responsible for contraction of smooth muscle?
Smooth muscles are stimulated to contract by catecholamines released by nerves in the vicinity of the muscle, as well as by a number of other hormones. Smooth muscles are also stimulated by the catecholamines in the bloodstream that originate in the secretions of the adrenal medulla.
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.
How do you identify smooth muscle tissue?
Smooth muscle cells are spindle shaped, have a single, centrally located nucleus, and lack striations. They are called involuntary muscles. Cardiac muscle has branching fibers, one nucleus per cell, striations, and intercalated disks. Its contraction is not under voluntary control.
Where is the smooth muscle found?
Smooth muscle fibers are located in walls of hollow visceral organs, except the heart , appear spindle-shaped, and are also under involuntary control. Skeletal muscle fibers occur in muscles which are attached to the skeleton. They are striated in appearance and are under voluntary control.
What connective tissue joins muscle to bone?
A tendon is a fibrous connective tissue which attaches muscle to bone. Tendons may also attach muscles to structures such as the eyeball.
