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Muscles & muscle tissue

List the characteristics and functions of muscle tissue.

  • skeletal: multinucleated, striated, voluntary

    • movement of body, maintain posture, stabilize joints, great heat

  • cardiac: uninucleated, striated, involuntary

  • smooth: uninucleated, unstriated, involuntary

  • all muscles are excitable, contract, extensible, & elastic

Discuss the organization of muscle tissue and its components.

  • myofilament→sarcomere→myofibril→muscle fiber→fascilce→muscle

  • the epimysium covers the outside of the muscle as an organ, the endomysium surround/seperate the individual muscle fibers, the perimysium wraps each fascicle

Discuss the anatomy of the muscle (cell) fiber and the microscopic anatomy of the muscle cell including the sarcomere as the basic unit of muscle contraction.

  • A muscle fiber is basically the cell of a muscle. It contains many nuclei and mitochondria that produce ATP for contraction. The mitochondria creates its own ATP so it doesn’t rely on another structure.

  • In a muscle fiber, there are myofibrils, the part of the muscle fiber that’s inside & rod-shaped. In this, the sliding filament occurs

  • In the H-zone of the A band, it appears less dense

  • the z discs lie in the I band, & they anchor the thins filaments

  • Troponin is a protein that controls the myosin-actin interactions in contraction along with tropomyosin

  • Sarcoplasmic reticulum: regulates intracellular levels of ionic Ca

  • T-tubules: allows changes in membrane potential to penetrate deep into the muscle rapidly fiber

  • ion channels (chemically gated): transfers substance such as acetylcholine

  • ion channels (voltage gated): opens/closes due to changes in membrane potential (depolarized)

Discuss the sliding filament theory of muscle contraction.

  • An axon & sarcolemma

Discuss the structure and function of the neuromuscular junction.

Describe the movement of the action potential in skeletal muscle.

Describe the ATP needs and the energy sources used by skeletal muscle.

Explain concepts in muscle physiology such as twitch, motor unit, and tetanus, as well as types of muscle fibers and muscle contractions.

Describe the relationship between bones and skeletal muscles in producing body movements.

Discuss selected muscle disorders.