4.1 neuromuscular function carter
Transcript of 4.1 neuromuscular function carter
Neuromuscular Function
Disclaimer – Mrs. Rowe did NOT create this – but I am sharing it.
Movement Analysis
Neuromuscular Function:I. The Motor Unit:
II. The Structure of Muscle Tissue:
III. The Role of Neurotransmitters in stimulating skeletal muscle contraction:
A. Acetylcholine (Ach): increases the post-synaptic membrane’s permeability to sodium and potassium ions spreading the impulse over the entire muscle fiber.
B. Cholinesterase: enzyme that breaks down Ach repolarizing the muscle fiber to await another nerve impulse.
IV. Skeletal Muscle Contraction:
A. The sliding filament theory:
Steps of a muscle contraction:
*Ca++ are released by the sarcoplasmic reticulum.
*Ca++ binds to troponin preventing the blocking action of tropomyosin.
Sliding filament cont.
*myosin heads can now attach to active sites on the actin filament.
*myosin heads pulls on the actin filament, decreasing the width of the sarcomere.
*myosin head releases the actin when a new ATP is formed.
V. Types of Muscle Fibers:
A. Slow Twitch: (type 1)*smaller in diameter*reddish color*use aerobic resp. for ATP
supply*contain more mitochondria*fire slowly, but take long to
fatigue.
B. Fast Twitch: used for short explosive movements, stop and go sports.
Type IIA:*large diameter*white in color*less mitochondria*uses both anaerobic and
aerobic energy transfer
Type IIB: *same physical
characteristics as Type IIA, but strictly uses the glycolytic anaerobic system.