Motor Systems/LMNs
Help!
|
|
||||
|---|---|---|---|---|---|
| What structure is said to be involved in "gating of volitional movements?" | basal ganglia
🗑
|
||||
| What is the relation of flexor to extensor motoneuron pools? | flexors are more dorsal within the ventral horn
🗑
|
||||
| What is the relation of proximal to distal muscle motoneuron pools? | proximal muscles are medial to distal muscles within ventral horn
🗑
|
||||
| Would one expect muscles of the medial rectus to have a high or low muscle fiber:motor unit ratio? | low (10 fibers per unit)
🗑
|
||||
| Would one expect muscles of the vastus lateralis to have a high or low muscle fiber:motor unit ratio? | high (1000 fibers per unit)
🗑
|
||||
| What type of neurons innervate intrafusal fibers? | gamma motoneurons
🗑
|
||||
| How much synaptic current is required to intiate repetitive firing of a motoneuron? | 1.5x the amount needed to recruit the neuron
🗑
|
||||
| Which type of muscle maximally contracts at higher frequencies (relative to the other muscle types)? | fast fatigable
🗑
|
||||
| Explain the concept of motor unit plasticity. | persistent changes in motor neuron activity can over time induce changes in muscle fiber type
🗑
|
||||
| How might an experimenter achieve more force from the muscles in the cats he is testing? | increase the firing rate of active units and recruit more units
🗑
|
||||
|
🗑
|
|||||
| Which type of muscle's nerve fibers will have the lowest threshold? | small motoneurons
🗑
|
||||
| If a firing rate of 20 Hz is needed to fully recruit all motor units of the soleus muscle, will a lower or higher frequency be needed to fully recruit a lateral rectus muscle? | lower freq
🗑
|
||||
| Explain the size principle of motoneurons. | Small motoneurons have a larger input resistance and thus a smaller current can is needed to successfully initiate a depolarization. Large motoneurons require more current to depolarize due to their small effective resistance
🗑
|
||||
| A 25 yr old pt with spinal muscular atrophy, a LMN disorder, should have what characteristic findings on exam? | focal atrophy or diffuse muscle wasting, fasciculations, muscle weakness, decreased DTRs
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
sirprakes
Popular Neuroscience sets