Lecture 11

Question 1

How are sensory inputs in the face broken down

Answer 1

three regions: V1, V2, V3

Question 2

Nerve for sensory imputs from the face and branches

Answer 2

trigeminal nerve (CN V), sensory info from face, also have motor branch for chewing (mastication)

Question 3

Where do branches of trigeminal nerve travel to

Answer 3

Come back to large ganglion where cell bodies of primary sensory neurons are located- trigeminal ganglion sits in merkels cave
Axons travel from these cell bodies and travel back to brainstem (at level of pons) where they synapse on nuclei situated throughout brainstem and upper spinal cord

Question 4

3 different nuclei that make up trigeminal nucleus

Answer 4

mesocephalic trigeminal nucleus, chief trigeminal nucleus, spinal trigmeninal nucleus

Question 5

Describe mesocephalic trigeminal nucleus

Answer 5

sits in midbrain, receives info from proprioception of jaw (mastication/chewing)

Question 6

Describe chief trigmeninal nucleus

Answer 6

receives nerve axons from receptors related to fine touch, corollary of PCML pathwa in face

Question 7

Pathway of chief trigmeninal nucleus

Answer 7

Nerves sits at rostal pons, synapse on cell bodies for second order sensory neurons which then cross midline and ascend to contralateral thalamus, 3rd order sensory neurons travel to face region of somatosensory cortex

Question 8

Describe spinal trigeminal nucleus

Answer 8

receives info for crude touch, pain and temp, corollary of anterolateral pathway

Question 9

Pathway of spinal trigeminal nucleus

Answer 9

axons enter at level of pons and descend to caudal medulla and rostal spinal cord, synapse on cell bodies in these region for second order sensory neurons, cross midline to opposite thalamus to face region of cortex

Question 10

result of damage to trigeminal nerve

Answer 10

ipsilateral damage

Question 11

Result of damage to somatosensory cortex of thalamus

Answer 11

contralateral damage

Question 12

Identify this

Answer 12

mesencephalic tract of CN V

Question 13

Identify this

Answer 13

Trigeminal ganglion

Question 14

Identify this

Answer 14

Primary snesory neurons

Question 15

Identify this

Answer 15

Chief sensory nucleus of CN V

Question 16

Identify this

Answer 16

Spinal tract of CN V

Question 17

Identify this

Answer 17

Spinal nucleus of CN V

Question 18

Describe damage with loss of pain and temp info on left face and right side of body

Answer 18

Damage to lateral pons affecting trigmeminal nerve and anterolatetal pathway. Body has already crosse over, face cross at higher cervical levels

Question 19

Describe damage to right side of face and right side of body

Answer 19

Damage to the thalamus, where body and face fibers converge, or damage to entire comatosensory cortex on contralateral side (unlikely if purley sensory symptoms)

Question 20

Describe what spinal cord sydomes can include

Answer 20

can include motor loss, sensory losss or both!

Question 21

What does spinal cord syndomes loss depend on

Answer 21

areas affected by injury, and pathways affected. Kinds of symptoms/ levels affected dependant on level and location of injury

Question 22

Damage to various areas of SC results

Answer 22

dorsal horn where primary sensory afferents come in, posterior column carry vibration an position sense, damage these areas sensory loss. Damage to anterolateral pathways, affect pain and temp sense, damage to anterior horn, motor losses

Question 23

Causes of transverse cord lesion

Answer 23

trauma, tumors, multiple sclerosis

Question 24

Describe degree/area of damage of transverse cord lesion

Answer 24

entire cord, both sides

Question 25

Describe symptoms for transverse cord lesion

Answer 25

Motor: -LMN symptoms for muscles innervated at level of injury, bilaterally -Damage to lateral corticospinal tract UMN symptyoms for muscles innervated below level of injury Sensory: -damage to posterior column and dorsal horn- loss of proprioception, vibration and light touch at mytome at level of injury and below level of injury bilaterally -damage to anterolateral pathways and commisure- loss of pain, crude touch, temp at level of injury and below level of injury bliaterally

Question 26

Causes of central cord syndrome

Answer 26

syringomyelia (fluid filled cavity in spinal cord), tumors, multiple sclerosis

Question 27

Describe degree area of damage of central cord syndrome

Answer 27

small lesion in central part of cord as gets larger involves other areas. Effects posterios column, amnd anterior horn as well as anterior commisure (affects second order sensory neurons anteriorlateral pathway) one/2 segments below.

Question 28

Causes of posterior cord syndrome

Answer 28

trauma e.g. compression of post cord, tumors in post column, multiple sclerosis (damage to white mater), Vit b12 deficiency (if severe enough can lead to degeneration of axons that run in posterior column), tabes dorsalis (disease causing degeneration of fibers)

Question 29

Describe symptoms fpr posterior cord syndrome

Answer 29

If purely damage to PCML pathways, loss of proprioception and light touch. Affects level of injury and levels below injury bilaterally. If have trauma dorsal horn may be affected too. Motor function, pain and temp function normal

Question 30

Causes of anterior cord syndrome

Answer 30

trauma, tumors, multiple sclerosis, infarct

Question 31

Describe area degree/ area of damage of posterior cord

Answer 31

damage to posterior cord, including posterior columns bilaterally

Question 32

Degree/area of damage of anterior cord syndrome

Answer 32

affects anterior part of cord, bilaterally

Question 33

Symptoms of anterior cord syndrome

Answer 33

motor: - LMN symtoms at level of injury bilaterally - Damage to corticospinal tracts , UMN sumyoms for muscles innervated below level of injury bilaterally Sensory: -damage to anterior lateral pathway and anterior commisure loss of pain, temp, crude touch 1 level below injury and all levels below that (preserved sensation at level of injury) - proprioception, light touch function preserved, comes in dorsal horn.

Question 34

Causes of hemicord lesion

Answer 34

-associated with brown-sequard syndrome: damage to one half of spinal cord Causes: penetrating trauma, compression from tumors, multiple sclerosis

Question 35

Symptoms of Hemicord lesion

Answer 35

Motor: - damage to anterior horn, LMN symptoms for muscle innervated at level of injury on ipsilateral side - Damage to corticospinal tract, UMN symptoms for all muscles below level of injury on ipsilateral side Sensory: - loss of proprioception, light touch at level of injury and below level of injury ipsilaterally - Damage to primary sensory neuron and second order sensory neuron, Loss of pain and crude touch for strip of dermatomes at level of injury and one segment below on ipsilateral side - loss of pain and temp for dermatomes 2 segments and below on contralateral side