Somatic Motor 2 Flashcards
- Receptor
- Sensory neuron
- Integration center
- Motor neuron
- Effector
Reflex Arcs
Five Components of
site of stimulus
Reflex Arcs
Receptor
transmits the afferent impulse to the CNS
Reflex Arcs
Sensory neuron
either monosynaptic or polysynaptic region within the CNS
Reflex Arcs
Integration center
conducts efferent impulses from the integration center to an effector
Reflex Arcs
Motor Neuron
muscle fiber or gland that responds to the efferent impulse
Reflex Arcs
Effector
For skeletal muscles to perform in a normal coordinated fashion, the nervous system needs
___ types of information:
Reflex Component Anatomy
2
Length of the muscle: provided by the
Reflex Component Anatomy
muscle spindles
Amount of tension in the muscles: provided by the
Reflex Component Anatomy
Golgi tendon organs (proprioceptors)
Composed of modified muscle fibers called intrafusal muscle fibers that are wrapped in a
connective tissue capsule (the spindle = fusal) and serve as receptive surfaces.
Muscle Spindles
Only the ends of the ___ are contractile & are innervated by gamma (gamma) efferent fibers
Muscle Spindles
Contractile skeletal muscle fibers are extrafusal fibers & are innervated by alpha (α) efferent fibers
Muscle Spindles
signals from the brain cause the muscle spindles to be more taut (greater force of extrafusal contraction can be anticipated; e.g. high vertical jump) or to be
less taut, as the situation demands
Operation of the Muscle Spindles
Gamma / efferent
Stretching the muscles also activates the ____, which then sends afferent impulses to the spinal cord
Muscle spindles
The greater the rate and degree of stretch, the ___ the impulse frequency
Muscle spindles
higher
Stretch Reflex
Patellar Reflex Example
Tapping the patellar tendon quickly - stretches the quadriceps and starts the reflex action
yes