Unit 3: Motor Systems Flashcards Preview

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Flashcards in Unit 3: Motor Systems Deck (25):
1

L1: _____ are collagen structures at the junction between a muscle and tendon and detect muscle stretch.

Golgi Tendon Organs

2

L1: _____ are mapped in the motor cortex.

Movements

3

L1: _____ are present in intrafusal muscle fibers and detect muscle stretch.

Muscle spindles

4

L1: _____ motor units are recruited first.

Smaller

5

L1: Motor unit: ______ alpha motor neuron(s) innverating _______.

a single; muscle fibers

6

L1: Which fiber type? Activate quickly, fatigue rapidly

Fast-twich glycolytic

7

L1: Which fiber type? Activate quickly, have many fibers, and fatigue moderately slowly

Fast-twitch oxidative

8

L1: Which fiber type? Fatigue very slowly due to high amounts of myoglobin and many mitochondria

Slow-twitch

9

L1: Which fiber type? Shorten extremely slowly and create isometric tension with low fatiguability

Tonic

10

L2: ______ can sense muscle stretch during muscle contraction via _______ innervation.

Muscle spindles; gamma-motor neuron

11

L2: ______ cannot detect muscle stretch during passive movement

Golgi Tendon Organs

12

L2: ______ neurons are not recruited in reflex pathways.

Gamma-motor

13

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

14

L2: Golgi Tendon Organis are oriented in ______ with muscle fibers and are innervated by group ______ afferents.

series; Ib

15

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

16

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

17

L2: Muscle spindles are oriented in ______ with muscle fibers and are innervated by group _____ afferents.

parallel; Ia and II

18

L2: Smaller motor neurons have _____ input resistance, such that the same stimulation elicits _____ voltage change.

increased; increased

19

L2: Smaller motor units tend to activate more _______-twitch fibers.

Slow

20

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

21

L2: Which brain structure? Involved in self-cued movements; highly activated during mental rehearsal of movement

Supplementary motor cortex

22

L2: Which brain structure? Involved when movement is initiated by an external cue

Premotor cortex

23

L2: Which brain structure? Invovled in anticipatory responses to a voluntary movement that help control posture and balance.

Reticular formation

24

L2: Which brain structure? Merges auditory and visual information onto a body coordinate system

Superior colliculus

25

L2: Which brain structure? Receives input from mesencephalic motor nucleus to regulate locomotor speed

Reticular formation