Spinal Tracts And Reflexes

1. Not all descending tracts decussate before synapsing at the level of the spinal cord.

True

False

The Lateral Vestibular Tract descends ipsilaterally the entire way from the vestibular nucleus to the spinal cord.

Explanation

The Lateral Vestibular Tract descends ipsilaterally the entire way from the vestibular nucleus to the spinal cord.

2. Because the Ventral/Anterior corticospinal tract descends ipsilaterally, it only affects the ipsilateral side.

True

False

It does descend ipsilaterally, but then it has a bilateral projection at the leve of the spinal cord causing it to synapse with LMN bilaterally.

Explanation

It does descend ipsilaterally, but then it has a bilateral projection at the leve of the spinal cord causing it to synapse with LMN bilaterally.

3. The Lateral Corticospinal Tract mostly synapses with interneurons in the spinal cord.

True

False

The LCT synapses with LMNs also, but mostly with interneurons.

Explanation

The LCT synapses with LMNs also, but mostly with interneurons.

4. The cell bodies of all descending spinal tracts are in the Motor Cortex.

True

False

The cell bodies of the Rubrospinal tract are in the red nucleus of the midbrain

Explanation

The cell bodies of the Rubrospinal tract are in the red nucleus of the midbrain

5. Which tract(s) descends through the Lateral Funiculus?

Spinalthalamic

Anterior (ventral) Corticospinal

Rubriospinal

Lateral Corticospinal

C & D

It is not B because thee Spinothalamic tract actually ASCENDS through the anterolateral column. The Anterior (ventral) Corticospinal Tract descends through the anterior funiculus. Both the Lateral Corticospinal and Rubio spinal descend through the lateral funiculus.

Explanation

It is not B because thee Spinothalamic tract actually ASCENDS through the anterolateral column. The Anterior (ventral) Corticospinal Tract descends through the anterior funiculus. Both the Lateral Corticospinal and Rubio spinal descend through the lateral funiculus.

6. The Lateral Corticospinal Tract exits the spinal cord at the...

Ventral Root

Dorsal Root

Dorsal Root Ganglion

It does not exit the spinal cord

Because the Lateral Corticospinal Tract is a motor tract, it will synapse with a motor neuron that exits the spinal cord at the ventral horn.

Explanation

Because the Lateral Corticospinal Tract is a motor tract, it will synapse with a motor neuron that exits the spinal cord at the ventral horn.

7. Which tract(s) decussates at the Medulla?

The Dorsal Column Medial Lemniscus

The Spinothalamic

The Rubrospinal

The Lateral Corticospinal

A & D

The STT(B) decussates at the level of the spinal cord. The Rubrospinal tract decussates at the midbrain. And while the Lateral corticospinal is descending and the DCML is ascending, they both decussate at the Medulla. The DCML crosses after synapsing at the nucleus cuneatus or gracilis. The Lateral Corticospinal crosses after passing through the medulla pyramid.

Explanation

The STT(B) decussates at the level of the spinal cord. The Rubrospinal tract decussates at the midbrain. And while the Lateral corticospinal is descending and the DCML is ascending, they both decussate at the Medulla. The DCML crosses after synapsing at the nucleus cuneatus or gracilis. The Lateral Corticospinal crosses after passing through the medulla pyramid.

8. Spinal Reflexes are the result of involuntary communication between Lower Motor Neurons and Upper Motor Neurons.

True

False

Spinal Reflexes are the results of involuntary communication between Lower Motor Neurons and SENSORY neurons, not Upper Motor Neurons. Upper Motor neurons may work to inhibit spinal reflexes, but they do not cause them.

Explanation

Spinal Reflexes are the results of involuntary communication between Lower Motor Neurons and SENSORY neurons, not Upper Motor Neurons. Upper Motor neurons may work to inhibit spinal reflexes, but they do not cause them.

9. Which statement is TRUE about the dorsolateral system tracts?

They travel through the anterior funiculus.

Their function includes limb flexion and fine movements

Includes the Lateral and Anterior Corticospinal Tracts

Terminates at the Anterior Funiculus

Affects mostly Extensor muslces

The correct answer is that the function of the dorsolateral system tracts includes limb flexion and fine movements. This means that these tracts are involved in controlling and coordinating the movements of limbs, allowing for precise and delicate movements as well as flexion of the limbs.

Explanation

The correct answer is that the function of the dorsolateral system tracts includes limb flexion and fine movements. This means that these tracts are involved in controlling and coordinating the movements of limbs, allowing for precise and delicate movements as well as flexion of the limbs.

10. Children with Cerebral Palsy display strong ATNR and STNR may be due to...

Damage to Lower Motor Neurons that occured in gestation

A hemisection spinal cord lesion caused by a genetic mutation

Bilateral symmetric malformation or swelling in the motor cortex

Loss of Dopamine in the Basal Ganglia

The swelling or malformation in the motor cortex may prevent the cortex from inhibiting the ATNR and STNR. Damage to the lower motor neurons would affect spinal cord reflexes. A hemisection lesion in spinal cord would not affect ATNR or STNR. While certain types of CP are a result of damage to the Badal Ganglia, it is typically not related to the loss of dopamine.

Explanation

The swelling or malformation in the motor cortex may prevent the cortex from inhibiting the ATNR and STNR. Damage to the lower motor neurons would affect spinal cord reflexes. A hemisection lesion in spinal cord would not affect ATNR or STNR. While certain types of CP are a result of damage to the Badal Ganglia, it is typically not related to the loss of dopamine.

11. The function of the Medial Longitudinal Fasciculus is

Trunk Postural Adjustments

Neck Postural Adjustments

Controls eye movements

Discrimintive Touch

Fast Pain

The MLF's function is to control eye motion. The Medial Vestibulospinal tract controls neck postural adjustments. The Lateral vestibulospinal tract controls trunk postural adjustments. The DCML is responsible for discriminitive touch and the STT is responsible for fast pain.

Explanation

The MLF's function is to control eye motion. The Medial Vestibulospinal tract controls neck postural adjustments. The Lateral vestibulospinal tract controls trunk postural adjustments. The DCML is responsible for discriminitive touch and the STT is responsible for fast pain.

12. Which statement is NOT true about the Symmetrical Tonic Neck Reflex (STNR)?

The STNR presents in typcial development until about 8-11 months of post-natal life

The STNR is a type of spinal cord reflex

The STNR is a precusor to crawling

In the STNR if the head is flexed, the arms flex and legs extend.

In the STNR if the head is extended, the arms extend & legs flex

A,C,D, and E are all true, however the STNR is actually a type of brain stem reflex which is why B is false.

Explanation

A,C,D, and E are all true, however the STNR is actually a type of brain stem reflex which is why B is false.

13. Which statement is true about the Myotatic Stretch Reflex?

This polysynaptic reflex starts with the lengthening of a muscle.

The lengthening of the muscle causes the Ia and II sensory axons to fire.

This ultimately results in the inhibition of the antagonist.

The Ia excites motor neurons (Gamma) to the same muscle, causing a contraction that opposes lengthening

A)is false because the MSR is a monosynaptic reflex, not polysynaptic. B) is false because only Ia sensory axons are fired. D) is false because the motor neurons are Alpha not Gamma. So C is the only true answer.

Explanation

A)is false because the MSR is a monosynaptic reflex, not polysynaptic. B) is false because only Ia sensory axons are fired. D) is false because the motor neurons are Alpha not Gamma. So C is the only true answer.

14. You encounter a patient with Brown-Sequard Syndrome. His hemisection lesion is at the C6 level (right side). Which of the deficits listed below would you expect to see with this individual? Select all that apply.

Paralysis in his left lower extremeties

Paralysis in his right lower extremeties

Loss of pain and temperature sensation on his left side below the lesion

Loss of discriminative touch on his left side below the lesion

Loss of discriminative touch on his right side below the lesion

Paralysis occurs on the ipsilateral side of the lesion, in this case the right side. Loss of pain and temperature occurs on the side contralateral to the lesion (in this case the left side). Loss of discriminative touch occurs on the ipsilateral side (in this case the right side).

Explanation

Paralysis occurs on the ipsilateral side of the lesion, in this case the right side. Loss of pain and temperature occurs on the side contralateral to the lesion (in this case the left side). Loss of discriminative touch occurs on the ipsilateral side (in this case the right side).

Submit

15. Select all the tracts that are in the Ventralmedial System, which travel through the anterior funiculus. You can select more than one answer.

Lateral Corticospinal

Medial Recticulospinal

Corticobulbar

Lateral Recticulospinal

Vestibulospinal

A, C, and D are all part of the Dorsolateral system and pass through the lateral funiculus.

Explanation

A, C, and D are all part of the Dorsolateral system and pass through the lateral funiculus.

Submit