Unit 3: Motor Systems Flashcards
L1: _____ are collagen structures at the junction between a muscle and tendon and detect muscle stretch.
Golgi Tendon Organs
L1: _____ are mapped in the motor cortex.
Movements
L1: _____ are present in intrafusal muscle fibers and detect muscle stretch.
Muscle spindles
L1: _____ motor units are recruited first.
Smaller
L1: Motor unit: ______ alpha motor neuron(s) innverating _______.
a single; muscle fibers
L1: Which fiber type? Activate quickly, fatigue rapidly
Fast-twich glycolytic
L1: Which fiber type? Activate quickly, have many fibers, and fatigue moderately slowly
Fast-twitch oxidative
L1: Which fiber type? Fatigue very slowly due to high amounts of myoglobin and many mitochondria
Slow-twitch
L1: Which fiber type? Shorten extremely slowly and create isometric tension with low fatiguability
Tonic
L2: ______ can sense muscle stretch during muscle contraction via _______ innervation.
Muscle spindles; gamma-motor neuron
L2: ______ cannot detect muscle stretch during passive movement
Golgi Tendon Organs
L2: ______ neurons are not recruited in reflex pathways.
Gamma-motor
L2: Flexion-extension coupling is mediated by __ afferent input from ______ that result in activation of excitatory and inhibitory interneurons in the spinal cord
Ib; Golgi Tendon Organs
L2: Golgi Tendon Organis are oriented in ______ with muscle fibers and are innervated by group ______ afferents.
series; Ib
L2: In overestimating force needed to lift an object the extrafusal fibers shorten ___ than the muscle spindle fibers, triggering a _____ firing rate of the muscle spindle, and feedback that _____ muscle tension.
more; decreased; decreases
L2: In underestimating force needed to lift an object the extrafusal fibers shorten ___ than the muscle spindle fibers, triggering a _____ firing rate of the muscle spindle, and feedback that _____ muscle tension.
less; increased; increases
L2: Muscle spindles are oriented in ______ with muscle fibers and are innervated by group _____ afferents.
parallel; Ia and II
L2: Smaller motor neurons have _____ input resistance, such that the same stimulation elicits _____ voltage change.
increased; increased
L2: Smaller motor units tend to activate more _______-twitch fibers.
Slow
L2: Stretching of _____ afferent fibers causes activation of alpha-motor neurons in the stretch muscle and ______ of alpha-motor neurons in the antagonist muscle
Ia; inhibition
L2: Which brain structure? Involved in self-cued movements; highly activated during mental rehearsal of movement
Supplementary motor cortex
L2: Which brain structure? Involved when movement is initiated by an external cue
Premotor cortex
L2: Which brain structure? Invovled in anticipatory responses to a voluntary movement that help control posture and balance.
Reticular formation
L2: Which brain structure? Merges auditory and visual information onto a body coordinate system
Superior colliculus
L2: Which brain structure? Receives input from mesencephalic motor nucleus to regulate locomotor speed
Reticular formation
