Where is muscular tissue located

Cardiac muscle fibers cells also are extensively branched and are connected to one another at their ends by intercalated discs. An intercalated disc allows the cardiac muscle cells to contract in a wave-like pattern so that the heart can work as a pump. 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 systems Figure 7.

Smooth muscle is also present in the eyes, where it functions to change the size of the iris and alter the shape of the lens; and in the skin where it causes hair to stand erect in response to cold temperature or fear. Although they do not have striations and sarcomeres, smooth muscle fibers do have actin and myosin contractile proteins, and thick and thin filaments. Skip to main content. Chapter 7: The Muscular System. Search for:. Types of Muscle Tissues.

Overview of Muscle Tissues. 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. The cells are striated and multinucleated appearing as long, unbranched cylinders. Cardiac muscle is involuntary and found only in the heart.

Each cell is striated with a single nucleus and they attach to one another to form long fibers. Cells are attached to one another at intercalated disks.

The cells are interconnected physically and electrochemically to act as a syncytium. Artery walls include smooth muscle that relaxes and contracts to move blood through the body.

The heart wall is composed of three layers. Cardiac muscle, found only in the myocardium, contracts in response to signals from the cardiac conduction system to make the heart beat.

Cardiac muscle is made from cells called cardiocytes. Like skeletal muscle cells cardiocytes have a striated appearance, but their overall structure is shorter and thicker. Cardiocytes are branched, allowing them to connect with several other cardiocytes, forming a network that facilitates coordinated contraction.

See more from our free eBook library. Newark: University of Delaware, Biological Sciences. How do muscles grow? Len Kravitz, Ph.

Muscle Attachment and Actions. Muscular System Pathologies.