Muscle 2 Flashcards
What is the main function of skeletal muscle
MOVEMENT (work= force x distance)
Myoneural junction: neuron, NT, Receptor
Alpha motor neuron; Acetylcholine; Nicotinic
Where is the receptor located
Motor end plate
What passes through the receptor when Acetylcholine is bound? What does this create?
Na+; action potential
Most muscles have which type of contraction?
Titanic
The mechanical activity of muscle depends on 3 things
Activation: number of motor units
Load: the external load that the muscle contracts against
Length: the resting length of the muscle
T/F Motor units do no behave in an all-or-none matter
FALSE
How is more force of a muscle produced?
by activating more motor units
What type of fibers are being recruited at low intensity and higher intensities?
Slow twitch- Type I
Fast twich- IIa first, then IIb
Isometric contraction
the force of the muscle equals the counterforce of the weight
the force of the muscle contraction equals the counterforce of opposing muscle contraction
Isotonic contraction
greater force of muscle contraction than the counterforce of the weight- the movement occurs at different speeds!! (same force)
length remains constant which force develops
isometric
muscle force remains constant while the muscle shortens
isotonic
resting length
length at which the muscle is held during contraction
optimal length
muscle length at which force capability is greatest (usually similar to the length of muscle in the body)
