Neuromusculoskeletal Systems

Question 1

A group of cell bodies in the CNS is called?

Answer 1

Nucleus i.e. basal ganglia, thalamus

Question 2

A group of axons in the CNS is called?

Answer 2

Tract i.e. corticospinal tract

Question 3

A group of cell bodies in the PNS is called?

Answer 3

Ganglion i.e. dorsal root ganglion

Question 4

A group of axons in the PNS is called?

Answer 4

A nerve i.e. femoral nerve

Question 5

What are the 3 somatosensory pathways?

Answer 5

Dorsal Column System (DCS)
Anterolateral System (ALS)
Trigeminal System (TS)

Question 6

Draw and label the DCS.

What does it do?

Answer 6

XXX
Delivers somatosensory information from the periphery to the contralateral cerebral cortex for conscious awareness of SS stimuli, specifically touch and proprioception.

Question 7

Draw and label the ALS.

What does it detect?

Answer 7

XXX

Transmits nociceptive information such as touch and temperature.

Question 8

Draw and label the TS.

What does it do?

Answer 8

XXX

Delivers info from face to cerebral cortex.

Question 9

State 2 differences between the DCS and ALS (SS pathways).

Answer 9

DCS primary afferent neuron axons are thicker in diameter and myelinated.

DCS crosses midline in brainstem, ALS crosses midline in spinal cord (or at close level to where it enters).

Question 10

What are the 4 motor pathways and what do they control?

Answer 10

Corticospinal tract - Voluntary movement/muscle fibers at NMJ
Corticobulbar tract - Voluntary movement of facial muscles
Reticulospinal tract - Postural control/muscle fibres of limb and trunk
Vestibulospinal tract - Postural control/muscle fibres of limb and trunk

Question 11

Draw the corticospinal tract and corticobulbar tract.

What is the difference between it and the corticobulbar tract?

Answer 11

XXX

Corticospinal UMNs synapse in the spinal cord whereas corticobulbar UMN synapse in the brainstem.

Question 12

Draw the reticulospinal tract and vestibulospinal tract.

What is the difference between it and the vestibulospinal tract?

Answer 12

XXX
The reticulospinal tract UMN originate in the reticular formation (in the brainstem) whereas the vestibulospinal tract UMN originates in the vestibular nucleus of brainstem.

Question 13

Draw a cerebral cortex and locate the below, and what happens here/what info comes here:

• Primary somatosensory cortex
• Primary motor cortex
• Primary visual cortex
• Posterior parietal cortex
• Pre-motor area

Answer 13

• Primary somatosensory cortex - front of parietal lobe in the post central gyrus, receives sensory info from DCS and ALS (medially) and TS (laterally) and sends to PPC for interpretation.
• Primary motor cortex - frontal lobe, at the back, in the pre-central gyrus. Motor plan execution occurs, corticospinal tract more medially (hand and limb), corticobulbar tract more laterally (face).
• Primary visual cortex - occipital lobe, recieves visual info and sends to PPC for interpretation.
• Posterior parietal cortex (PPC) - parietal lobe, interprets sensory info into psychologically meaningful information (perception) and generates plan with pre-motor area.
• Pre-motor area - frontal lobe, generates a movement plan along with PPC.

Question 14

Where does a motor/movement plan go for ‘review and modification’?

Answer 14

Basal ganglia and cerebellum.

Goes to either, then back to the cerebral cortex via the thalamus.

Question 15

Draw and label the vestibular pathway.

What are the SS receptors?

Answer 15

XXX

Hair cells, located in the utricle, saccule and semicircular canals.

Question 16

Draw and label the visual pathway.

Answer 16

XXX

Photoreceptors in the retina.

Question 17

Draw a ‘normal’ muscle stretch reflex going from the spinal cord to a calf muscle.

Answer 17

XXX

Question 18

What would you typically expect to see in UMN injury vs LMN injury?

Answer 18

UMN injury - typically stiff gait

LMN - typically floppy gait

Question 19

What are common sources of input to LMN’s?

Answer 19

UMNs (voluntary motor control), primary afferent neurons (reflex motor control) and interneurons.