Extra MS stuff

Characteristics of Muscle Tissues:

  • Skeletal, smooth, and cardiac muscles

  • Voluntary (skeletal) vs. Involuntary (smooth, cardiac)

  • Striated (skeletal, cardiac) vs. Non-striated (smooth)

  • Multinucleated (skeletal) vs. Uninucleated (smooth, cardiac)

Membranes in Microscopic Muscle:

  1. Endomysium:

    • Location: Surrounds individual muscle fibers

    • Function: Supports and protects muscle fibers

  2. Perimysium:

    • Location: Surrounds bundles of muscle fibers (fascicles)

    • Function: Provides structure and carries blood vessels and nerves

  3. Epimysium:

    • Location: Surrounds the entire muscle

    • Function: Connects muscle to surrounding tissues, provides a pathway for nerves and vessels

Axon Terminal Channels:

  • Voltage-gated calcium channels (Ca2+ channels)

Ligaments vs. Tendons:

  • Ligaments:

    • Connect bone to bone

    • Provide joint stability

  • Tendons:

    • Connect muscle to bone

    • Transmit muscle force to bone for movement

Sliding Filament Theory Mechanisms:

  1. Cross-Bridge Formation:

    • Myosin binds to actin, forming a cross-bridge

  2. Power Stroke:

    • Myosin head pivots, pulling actin towards the center

  3. Cross-Bridge Detachment:

    • ATP binds to myosin, causing detachment

  4. Cocking of Myosin Head:

    • Energy from ATP hydrolysis cocks myosin head for the next cycle

ATP in Active Myosin:

  • 1 ATP needed for each cycle of myosin cross-bridge activity

Muscle Burning:

  • Lactic acid accumulation due to anaerobic metabolism during intense exercise

Rigor Mortis:

  • Calcium floods into muscles post-mortem

  • Lack of ATP prevents cross-bridge detachment

Neuromuscular Junction:

  • Ions:

    • Calcium (Ca2+)

    • Sodium (Na+)

    • Potassium (K+)

  • Neurotransmitters:

    • Acetylcholine (ACh)

Origins and Insertions of Muscles:

  • Origin:

    • Attachment site with less movement during contraction

  • Insertion:

    • Attachment site with more movement during contraction

Prime Mover vs. Antagonists:

  • Prime Mover:

    • Muscle primarily responsible for a specific movement

  • Antagonists:

    • Muscles opposing the prime mover, providing resistance

Purpose of Membranes:

  • Endomysium, Perimysium, Epimysium:

    • Provide structural support, carry blood vessels and nerves