Newark: University of Delaware, Biological Sciences. How do muscles grow? Len Kravitz, Ph. Muscle Attachment and Actions. Muscular System Pathologies.
When you select "Subscribe" you will start receiving our email newsletter. Use the links at the bottom of any email to manage the type of emails you receive or to unsubscribe. See our privacy policy for additional details. Learn Site. Artery walls include smooth muscle that relaxes and contracts to move blood through the body 3.
Get our awesome anatomy emails! About News Contact. Explanation: Shape of skeletal muscle fibre is cylindrical: that of cardiac muscle fibre is ribbon like. Mohan M. Structurally cardiac muscles are striated muscles. But cardiac muscles are involuntary. Explanation: Majority of striated muscles act quickly. Related questions Why do muscles work in pairs? How do muscles and bones work together? How do muscle cells differ from nerve cells? What are some examples of muscles?
What are muscles? Myocytes and their numbers remain relatively constant throughout life. Skeletal muscle tissue is arranged in bundles surrounded by connective tissue. Under the light microscope, muscle cells appear striated with many nuclei squeezed along the membranes.
The striation is due to the regular alternation of the contractile proteins actin and myosin, along with the structural proteins that couple the contractile proteins to connective tissues.
The cells are multinucleated as a result of the fusion of the many myoblasts that fuse to form each long muscle fiber. Cardiac muscle forms the contractile walls of the heart. The cells of cardiac muscle, known as cardiomyocytes, also appear striated under the microscope.
Unlike skeletal muscle fibers, cardiomyocytes are single cells with a single centrally located nucleus. A principal characteristic of cardiomyocytes is that they contract on their own intrinsic rhythm without external stimulation. Cardiomyocytes attach to one another with specialized cell junctions called intercalated discs.
Intercalated discs have both anchoring junctions and gap junctions. Attached cells form long, branching cardiac muscle fibers that act as a syncytium, allowing the cells to synchronize their actions.
The cardiac muscle pumps blood through the body and is under involuntary control. Smooth muscle tissue contraction is responsible for involuntary movements in the internal organs.
It forms the contractile component of the digestive, urinary, and reproductive systems as well as the airways and blood vessels. Each cell is spindle shaped with a single nucleus and no visible striations Figure 4. Watch this video to learn more about muscle tissue. In looking through a microscope how could you distinguish skeletal muscle tissue from smooth muscle? The three types of muscle cells are skeletal, cardiac, and smooth. Their morphologies match their specific functions in the body.
Skeletal muscle is voluntary and responds to conscious stimuli.
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