Descending Motor Pathways

Question 1

Damage to upper motor neurones can result in what 5 symptoms?

Answer 1

Paralysis
Paresis
Reflex loss
Fibrillations
Fasciculations

Question 2

In the ventral horn of the spinal cord, distal musculature controls what?

Answer 2

Fine movements (e.g fingers)

Question 3

In the ventral horn of the spinal cord, proximal and axial musculature controls what?

Answer 3

Positioning

Question 4

What is the function of the lateral corticospinal tract?

Answer 4

Voluntary control of distal musculature (controls fine movements)

Question 5

What is the function of the anterior corticospinal tract?

Answer 5

Voluntary control of proximal musculature (controls position)

Question 6

What is the function of the reticulospinal tract?

Answer 6

Regulate flexor muscle reflexes and initiate patterned activity (locomotion)

Question 7

What is the function of the rubrospinal tract?

Answer 7

Motor control; excitement of flexors

Question 8

What is the function of the tectospinal tract?

Answer 8

Mainly cervical termination, orientation to visual stimuli

Question 9

The superior caliculi is associated with what?

Answer 9

Visual

Question 10

The inferior caliculi is associated with what?

Answer 10

Auditory

Question 11

What is the function of the vestibulospinal tract?

Answer 11

Lateral controls anti-gravity muscles

Medial regulates head movements

Question 12

Where does the lateral corticospinal tract cross over?

Answer 12

At pyramidal decussation

Question 13

Where does the anterior corticospinal tract cross over?

Answer 13

At segmental level of spinal cord

Question 14

Corticobulbar tract innervates which cranial nerves?

Answer 14

V - Trigeminal
VII - Facial
XI - Accessory
XII - Hypoglossal

Question 15

How can upper motor neurones damage (corticospinal) be identified?

Answer 15

Positive Babinski Sign

Question 16

Describe the Babinski sign?

Answer 16

Abnormal fanning of toes and extension of big toe. Plantar flexion occurs as opposed to normal dorsiflexion

Question 17

Lesions above the red nucleus lead to which condition?

Answer 17

Decorticate posturing (hyper flexion of upper extremities)

Question 18

Lesions below the red nucleus lead to which condition?

Answer 18

Decerebrate posturing (hyper extension of upper extremities)

Question 19

Describe the route the Pontine recticulospinal tract takes?

Answer 19

Ipsilateral

Question 20

Describe the route the Medullary reticulospinal tract takes?

Answer 20

Both contralateral and ipsilateral