10_LectureOutline

10_LectureOutline - An Introduction to Muscle Tissue Muscle...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: An Introduction to Muscle Tissue Muscle Tissue A primary tissue type, divided into Skeletal muscle Cardiac muscle Smooth muscle Skeletal Muscles Are attached to the skeletal system Allow us to move The muscular system Includes only skeletal muscles Functions of Skeletal Muscles Produce skeletal movement Maintain body position Support soft tissues Guard openings Maintain body temperature Store nutrient reserves Skeletal Muscle Structures Muscle tissue (muscle cells or fibers ) Connective tissues Nerves Blood vessels Organization of Connective Tissues Muscles have three layers of connective tissues Epimysium: exterior collagen layer connected to deep fascia Separates muscle from surrounding tissues Perimysium: surrounds muscle fiber bundles (fascicles) contains blood vessel and nerve supply to fascicles Endomysium: surrounds individual muscle cells (muscle fibers) contains capillaries and nerve fibers contacting muscle cells contains myosatellite cells (stem cells) that repair damage Muscle attachments Endomysium, perimysium, and epimysium come together: at ends of muscles to form connective tissue attachment to bone matrix i.e., tendon (bundle) or aponeurosis (sheet) Nerves Skeletal muscles are voluntary muscles, controlled by nerves of the central nervous system (brain and spinal cord) Blood Vessels Muscles have extensive vascular systems that Supply large amounts of oxygen Supply nutrients Carry away wastes Skeletal Muscle Fibers Are very long Develop through fusion of mesodermal cells ( myoblasts ) Become very large Contain hundreds of nuclei Internal Organization of Muscle Fibers The sarcolemma The cell membrane of a muscle fiber (cell) Surrounds the sarcoplasm (cytoplasm of muscle fiber) A change in transmembrane potential begins contractions Transverse tubules (T tubules) Transmit action potential through cell Allow entire muscle fiber to contract simultaneously Have same properties as sarcolemma Myofibrils Lengthwise subdivisions within muscle fiber Made up of bundles of protein filaments ( myofilaments ) Myofilaments are responsible for muscle contraction Types of myofilaments: thin filaments : made of the protein actin thick filaments : made of the protein myosin Sarcoplasmic reticulum (SR) A membranous structure surrounding each myofibril Helps transmit action potential to myofibril Similar in structure to smooth endoplasmic reticulum Forms chambers ( terminal cisternae ) attached to T tubules Triad Is formed by one T tubule and two terminal cisternae Cisternae: concentrate Ca 2+ ( via ion pumps) release Ca 2+ into sarcomeres to begin muscle contraction Sarcomeres The contractile units of muscle Structural units of myofibrils...
View Full Document

Page1 / 15

10_LectureOutline - An Introduction to Muscle Tissue Muscle...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online