Descending Motor Tracts

Question 1

Hypertonia

Answer 1

increased rigidity

caused by upper motor neuron lesions

Question 2

Hyperreflexia

Answer 2

increased muscle reflexes

caused by upper motor neuron lesions

Question 3

Clonus

Answer 3

involuntary, rhythmic muscle contractions

caused by upper motor neuron lesions

Question 4

Babinski sign

Answer 4

test of reflex on bottom of foot

babies: flex toes up
adults: curl tores (normal); flex toes = upper motor neuron injury

Question 5

Flaccid Paralysis

Answer 5

paralysis accompanies by loss of muscle tone

lower motor neuron damage

Question 6

Pyramidal Tracts

Answer 6

• corticospinal
• corticobulbar
• originate in CEREBRAL CORTEX
• responsible for VOLUNTARY control of muscles

Question 7

Extrapyramidal Tracts

Answer 7

• vestibulospinal
• reticulospinal
• rubrospinal
• tectospinal
• original in BRAINSTEM
• responsible for INVOLUNTARY control of muscles

Question 8

Corticospinal Tracts

Answer 8

• supply muscles of the body below the neck
• cerebral cortex –> internal capsule –> brainstem (medulla)
• anterior corticospinal tract
• lateral corticospinal tract

Question 9

Anterior Corticospinal Tract

Answer 9

PROXIMAL (trunk) MUSCLES

• stays ipsilateral until decussates right before it exist the spinal cord
• terminates in cervical / upper thoracic

Question 10

Lateral Corticospinal Tract

Answer 10

DISTAL (limb) MUSCLES

• decussates to contralateral brainstem in medulla before it enters spinal cord
• via decussation of the pyramids

Question 11

Corticobulbar Tracts

Answer 11

• supply muscles of head, neck and face
• only tract that terminates within brainstem (never enters spinal cord)
• bilateral innervation

Question 12

Reticulospinal Tracts

Answer 12

• automatic/ involuntary movements of locomotion / posture control
• do not decussate, IPSILATERAL INNERVATION @ ALL LEVELS

Question 13

Medial Reticulospinal Tract

Answer 13

• EXTENSOR motor neurons (for postural support and patterned movements)
• from reticular formation in PONS

Question 14

Lateral Reticulospinal Tract

Answer 14

• FLEXOR motor neurons, enables modulation of stretch reflex

- from reticular formation in medulla

Question 15

Vestibulospinal Tracts

Answer 15

• control balance and posture

Question 16

Medial Vestibulospinal Tract

Answer 16

• control head movements

medial vestibular nuclei –> descends BILATERALLY –> terminates in cervical spinal cord

Question 17

Lateral Vestibulospinal Tract

Answer 17

• controls body posture

lateral & inferior vestibular nuclei –> descends IPSILATERALLY –> terminates @ all levels

Question 18

Tectospinal Tract

Answer 18

• movements of the head in relation to visual stimuli

begins at SUPERIOR COLLICULUS –> DECUSSATES @ MIDBRAIN –> terminates in upper cervical levels

Question 19

Rubrospinal Tract

Answer 19

• fine motor control of hand movements

originates from RED NUCLEUS –> DECUSSATE @ Midbrain –> terminates in cervical level w/ contralateral innervation

Question 20

Primary Motor Cortex

Answer 20

execution of movement

Question 21

Supplemental Motor Area

Answer 21

Execution of Sequences of movement

Question 22

Premotor cortex

Answer 22

planning of movement