Lab 4 Flashcards
Define skeletal muscles
muscles attached to bones
T/F Each skeletal muscle is composed of 10 individual muscle fibers
F, it is composed of thousands of individual muscle fibers
What are motor units composed
a motor axon and all the muscles it innervates
T/F a single action potential in one motor axon leads to the synchronous excitation and contraction of all muscle fibers in that motor unit
T
Electromyogram
measures the extracellular recording of electrical activity in a whole muscle
where does the neural stimulus begin to contract skeletal muscles?
motor cortex
T/F skeletal muscles usually contract even without a triggering stimulus from the nervous system
F, they do not contract unless they receive a triggering stimulus from the nervous system
Voluntary movement
conscious intent to generate a specific skeletal muscle contraction
what is an example of an involuntary, reflex action that will be tested on this lab
Achilles tendon
stretch reflex pathway
the contraction of a muscle in response to its passive stretching that increases its contractility
define involuntary, reflex action
the contraction of a muscle in response to a stimuli , not a conscious intent
where can the motor neurons that control calf muscle function be found
lumbar and sacral levels
synaptic delay
is the time necessary for chemical neurotransmission associated with reflex synapses to occur
what is the equation for conduction velocity
( total length of reflex pathway X 2)/ (reflex latency - 2 msec)
antagonistic movement is
a second muscle that opposes the movement of the first muscle contraction
