Lecture Three Flashcards
(52 cards)
what is the function of a muscle
generate force, allows for movement
what is the function of a motor neuron
signal muscle to contract allows for voluntary control
why are muscles and motor neurons important for exercise
exercise requires coordinated movements involving multiple muscle groups and varied amounts of force
what are the parts of a muscle
muscle- fasicle- fiber- myofibril- sarcomere- thick/thin
what are the structures in a muscle fiber
sarcolemma transverse tubules sarcoplasmic reticulum mitochondria nucleus
what is a muscle fiber that is enclosed by a plasma membrane called
sarcolemma
what in the muscle stores calcium
sarcoplasma reticulum
what is the purpose of calcium in the muscle
moves troponin off, allowing tropomyosin to dissociate and expose the actin for binding
what is a thin filament
actin
what is a thick filament
myosin
facts of sarcomere
smallest functional unit of a muscle composed of thick and thin filament
2/3 of all muscle protein is made of
myosin
what are thin filament proteins
actin troponin tropomyosin
what are the thick filament proteins
myosin
what is the function of an alpha motorneuron
conduct impulse signals from CNS to muscle and initiate a contraction
where are motorneurons grouped together
spinal cord
motor neurons innervates what fibers
alpha motorneurons
what composes a motor unit
neuron and muscle it innervates
smaller motor unit size is used for
dexterity
larger motor unit size is used for
force
what is the neuromuscular junction
area where nerve “connects” to muscle fiber
what signals are used in the neuromuscular junction
acetylcholine
what maximizes contact for ACh release and capture in neuromuscular junction
shape and structure
what are the four muscle fiber types
Type 1 : slow twitch Type 2a Type 2b Type 2x