Module E-01

Question 1

Lower Motor neuron

Answer 1

Motor neurons that communicate directly with somatic

muscle.

Question 2

Upper Motor neuron

Answer 2

– Motor neurons arising from motor centers in the brain
that communicate either directly with lower motor neurons or indirectly via local interneurons
-

Question 3

Plegia?

Answer 3

Paralysis.

Question 4

Pariesis

Answer 4

Subparalytic muscle weakness

Question 5

Hemipariesis

Answer 5

Paralysis on one side of the body

Question 6

Pyramidal motor system aka

Answer 6

corticospinal tracts

Question 7

Where do lower motor neurons arise from?

Answer 7

either the spinal cord (contributing to spinal nerves) or the brainstem (contributing to cranial nerves).

Question 8

Rubrospinal tract starts from ___________

Answer 8

the red nucleus

Question 9

Name 4 Voluntary Motor pathways

Answer 9

1) Corticospinal
2) Corticobulbar
3) Rubrospinal
4) the 2 Reticulospinal

Question 10

______________ is an involuntary pathway receive sensory input from the vestibular nuclei

Answer 10

VetsibuloSpinal

Question 11

The motor systems receive somatosensory feedback from

Answer 11

1) the dorsal column/medial lemniscal pathways,
2) the anterolateral system (ALS),
3) the somatosensory cortex
4) the spinoreticular tracts

Question 12

What is the purpose of Decussation of the Upper motor neurons?

Answer 12

Allows many motor centers exert either bilateral or contralateral muscular control

Question 13

What is Start point of Lateral corticospinal Tract?

Answer 13

Pyramidal cells (layer 5) of Brodmann’s area 4

Question 14

What is Start point of Corticobulbar Tract?

Answer 14

Pyramidal cells (layer 5) of Brodmann’s area 4

Question 15

What is Start point of Rubrospinal Tract?

Answer 15

Red nucleus (midbrain)

Question 16

What is Start point of Lateral vestibulospinal Tract?

Answer 16

Lateral vestibular nucleus (largely pontine)

Question 17

What is Start point of Medial vestibulospinal Tract?

Answer 17

Medial vestibular nucleus in pons & medulla

Question 18

What is Start point of Pontine (medial) reticulospinal Tract?

Answer 18

Oral and caudal reticular nuclei in pons (Pontine reticular formation)

Question 19

What is Start point of Medullary (lateral) reticulospinal Tract?

Answer 19

Gigantocellular reticular nucleus in medulla (Medullary reticular formation)

Question 20

3 Pathways that end Ventromedial tracts

Answer 20

1) Pontine (medial) reticulospinal
2) Lateral vestibulospinal
3) Medial vestibulospinal

Question 21

3 Pathways that end Lateral tracts

Answer 21

1) Lateral corticospinal
2) Rubrospinal
3) Medullary (lateral) reticulospinal

Question 22

Flexor and adductor neurons lie _________ in the ventral horn

Answer 22

dorsal

Question 23

Extensor and abductor neurons lie _________ in the ventral horn

Answer 23

Ventral

Question 24

Neurons for distal muscles lie ________ to those for truncal structures (i.e., proximal muscles)

Answer 24

Lateral

Question 25

Lateral pathways are biased for _______ of the limbs and their SPINAL neurons lie in the _________ of the ventral horn

Answer 25

flexion; dorsal portion

Question 26

Medial (Ventromedial) Pathways are Biased for ________ of the Limbs and their SPINAL neurons lie in the _________ of the ventral horn

Answer 26

Extension; ventral portion

Question 27

Disease that affects Lower Motor Neurons

Answer 27

ALS

Question 28

ALS

Answer 28

Amyotrophic Lateral Sclerosis

Question 29

What is ALS

Answer 29

a progressive neuromuscular disease that initially affects and later destroys lower motor neurons and eventually also parts of the corticospinal/corticobulbar tracts and the primary motor area (precentral gyrus and anterior paracentral lobule).

Question 30

Symptoms of ALS

Answer 30

– atrophy, weakness, fasciculations, spasms, and cramping of affected muscles; 50% of cases begin in one or both hands – loss of muscle bulk in thenar, hypothenar, interossei, arm and shoulder – reduction of cough reflex => risk of aspiration pneumonia – involvement of bulbar motor nuclei => difficulty in swallowing, coughing, and speaking. – weakness, atrophy, and fasciculations in tongue – involvement of pharyngeal and laryngeal muscles – death occurs from respiratory insufficiency and aspiration pneumonia

Question 31

What are Fasciculations?

Answer 31

random contraction of denervated muscle

Question 32

Cause of Anterior Spinal Artery Syndrome

Answer 32

-Anterior spinal arterial infarction -Less common causes include tumors and epidural spinal abscesses

Question 33

Where is the Anterior Spinal artery located?

Answer 33

the anterior median fissure

Question 34

Symptoms of Anterior Spinal Artery Syndrome

Answer 34

– spastic paraparesis – bilateral extensor plantar response – bilateral loss of pain and temperature below lesion – touch, vibration, proprioception intact – retention of urine – sexual functions impaired

Question 35

Most common cause of Central Medullary Syndrome

Answer 35

Syringomyelia | other causes include tumors and hemorrhages

Question 36

Cause of Syringomyelia

Answer 36

a longitudinal cyst that develops along the central canal. The cyst usually expands ventrally and compresses the ventral horns and the ventral white commissure

Question 37

Which area does Syringomyelia most commonly occur?

Answer 37

Cervical cord

Question 38

Symptoms of Syringomyelia

Answer 38

segmental muscular atrophy (most frequently, muscles of hand are affected due to cervical involvement) and also a loss of pain and temperature senses due to destruction of the anterior white commissure