Motor Control and Motor Unit Flashcards
Which muscle type does the following characterization describe?
Upper limit for twitch tension is low
Slow twitch
Which motor unit does the following description characterize?
Current threshold for activation is high
FF MU
Which type of movement occurs without any neural input?
Passive movement
Which muscle type does the following characterization describe?
Energy source is aerobic and anaerobic glycolysis
Oxidative glycolytic fast twitch
What is a fasciculation?
Visible twitches that result from the activation of an entire motor unit
True or False: Stereotyped movement does NOT depend on central pattern generators
FALSE.
Stereotyped movement depends on central pattern generators.
Define motor pool
alpha-motor neurons that innervate a single muscle
Which motor unit does the following description characterize?
Low upper limit for tetanic tension
S MU
What is the maximal duration of continuous activation of glycolytic fast twitch fibers
5 minutes or less
What is the maximal duration of continuous activation of FF motor units?
5 mins or less
How many motor neurons control a typical muscle?
100
Which muscle fiber makes up a motor unit that can be described as “fatigue-resistant”
Oxidative glycolytic fast twitch
What is the smallest division of movement?
Motor unit
Which motor unit does the following description characterize?
Input resistance is low
FF MU
Which muscle type does the following characterization describe?
Maintains force for short periods of time
Fast twitch
Which muscle type does the following characterization describe?
Less vascularized
Fast twitch
In the absence of neural input,
A) None of the fibers in the motor unit contract
B) Some of the fibers in the motor unit contract
C) All of the fibers in the motor unit contract
A) None of the fibers in the unit contract
Which motor unit does the following description characterize?
Intermediate upper limit for tetanic tension
FR MU
Which muscle type does the following characterization describe?
pale in color
Fast twitch
Which motor unit does the following description characterize?
Maximal duration of continuous activation is hours
S MU
Which muscle type does the following characterization describe?
Speed of contraction is intermediate
Oxidative glycolytic fast twitch
Gazing at a painting or gasping at a story told by a friend are both examples of what?
Self-generated actions
Which has more fast twitch fibers proportionally, the soleus or the orbicularis oculi?
Orbicularis oculi
Small, slow units are active during smooth control/poor control
Smooth control
What is a self-generated action?
Occurs in response to a stimulus, removed from a sensory input
Which motor unit does the following description characterize?
Current threshold for activation is low
S MU
Complete dysfunction in MN, NMJ, or muscle - muscles have no tone.
This description best characterizes which of the following?
A) Akinesia B) Spastic paralysis C) Volitional Paresis D) Flaccid Paralysis E) Emotional Paresis
D) Flaccid paralysis
Which muscle type does the following characterization describe?
Upper limit for twitch tension is high
Glycolytic fast twitch
Lack of movement, damage to the basal ganglia - seen in severe PD patients
This description best characterizes which of the following?
A) Akinesia B) Spastic paralysis C) Volitional Paresis D) Flaccid Paralysis E) Emotional Paresis
A) Akinesia
Define A-reflexia
Lack of reflexes
Which muscle type does the following characterization describe?
Can be large because force depends on cross sectional area
Fast twitch
Which motor unit does the following description characterize?
High upper limit for tetanic tension
FF MU
Which motor unit does the following description characterize?
Rise time is intermediate
FR MU
Which muscle type does the following characterization describe?
Speed of contraction is fast
Fast twitch fibers
Which muscle type does the following characterization describe?
Upper limit for twitch tension is intermediate
Oxidative glycolytic fast twitch
Which muscle type does the following characterization describe?
Requires oxygen to function
Slow twitch; oxidative glycolytic fast twitch CAN use oxygen, but does not require it.
Which type of movement involves the coordinated function of various muscles and motor commands to control for fatigue, balance, weight (load)
Smooth movement
Which muscle type does the following characterization describe?
Speed of contraction is slow
Slow-twitch
Small, slow units are active during low/high force contractions
Low force contractions
Why would fasciculations get larger after denervated muscle wasting?
Because the surviving motor neurons will rennervate the surviving fibers
When a motor unit fires,
A) None of the fibers in the unit contract
B) Some of the fibers in the unit contract
C) All of the fibers in the unit contract
C) All of the fibers in the unit contract
Which muscle type does the following characterization describe?
Contains glycogen stores
Fast twitch
What part of the brain does volitional action involve?
Central cortex