3.5 Muscle Tissue

• Muscle tissue is capable of powerful contractions that shorten its cells along the longitudinal axis
• Sarcoplasm is the cytoplasm of a muscle cell
• Sarcolemma is the plasma membrane
• Skeletal muscle tissue contains large (size) cells
• Muscle fibers are long and slender individual skeletal muscle cells
• Muscle cells are multinucleate (refers to nucleus)
• Myosatellite cells are a type of stem cells
• Actin and myosin contractile filaments are arranged in a parallel pattern, look banded or striated
• The skeletal muscle is also called striated voluntary muscle
• Areolar connective tissue binds skeletal muscle together, blending to tendons and aponeurosis
• Cardiac muscle is found in the heart.
• Cardiac muscle cell is smaller than skeletal muscle fibers and has only one nucleus
• Intercalated discs are regions where cardiac muscle cells form extensive connections for communication
• Cardiac muscle cannot divide and lack myosatellite cells so they cannot regenerate
• Cardiac muscle does not reply on the nervous system
• Pacemaker cells are specialized cardiac muscle cells that establish a regular rate of contraction
• The nervous system can alter the cardiac muscle but it does not control it, which is why it is known as the striated involuntary muscle
• Smooth muscle is found in the walls of blood vessels around hollow organs
• Smooth muscle tissue can divide and regenerate
• Smooth muscle pattern is non-striated
• Smooth muscle can contract with pacemaker cells and the nervous system
• Smooth muscle tissue has no voluntary control so it is called nonstriated involuntary muscle