Cervical mets

Question 1

Myotomes for shoulder abduction

Answer 1

C5,C6

Question 2

Myotomes for shoulder adduction

Answer 2

C6-C8

Question 3

Myotomes for elbow flexion

Answer 3

C5,C6

Question 4

Myotomes for elbow extension

Answer 4

C7-C8

Question 5

Myotomes for wrist flexion

Answer 5

C6,C7

Question 6

Myotomes for wrist extension

Answer 6

C7,C8

Question 7

Myotomes for finger flexion

Answer 7

C7,C8

Question 8

Myotomes for finger extension

Answer 8

C7,C8

Question 9

Myotomes for finger abduction

Answer 9

C8,T1

Question 10

Myotomes for finger adduction

Answer 10

C8,T1

Question 11

Myotomes for triceps reflex

Answer 11

C7,C8

Question 12

Myotomes for biceps reflex

Answer 12

C5,C6

Question 13

Dermatomes for C4

Answer 13

Deltoid

Question 14

Dermatomal distribution for C5

Answer 14

Lateral aspect of upper arm

Question 15

Dermatomal distribution for C6

Answer 15

Lateral aspect of forearm, thenar eminence

Question 16

Dermatomal distribution for C7

Answer 16

Middle finger and a bit of mid-palm region

Question 17

Dermatomal distribution for C8

Answer 17

Medial aspect of forearm, pinkie, ring finger, hypothenar eminence

Question 18

Dermatomal distribution for T1

Answer 18

Medial aspect of upper forearm

Question 19

Dermatomal distribution for T2

Answer 19

Medial aspect of upper forearm and axilla

Question 20

Describe the spinothalamic tract

Answer 20

Sensory, ascending tract, 3-order neuron pathway
Function: pain, temperature and fine touch
1st order neuron: DRG

2nd order neuron: synapses a couple levels above at the substantia gelatinosa –> decussates @ anterior white commissure and ascends to the thalamus

3rd order: synapses at the ventroposterolateral nucleus and then towards the post-central gyrus in the cortex - primary somatosensory cortex

Question 21

Describe the corticospinal tract

Answer 21

Motor, descending tract, 2-order neuron pathway
Function: coordinate and voluntary movements

1st order: pre-central gyrus - primary motor cortex descends

90% pyramidal decussation - lower limbs - lateral corticospinal tract
The rest are upper limbs - anterior corticospinal tract
- anterior horn commissure decussation at level of innervation

2nd order: NMJ - innervates muscle

Question 22

Describe the dorsal column medial lemniscus tract

Answer 22

Sensory, ascending tract, 3-order neuron pathway
Function: crude touch, proprioception and vibration

1st order: DRG peripherally
2rd order: cuneate (Lateral - above T6); gracile nucleus (medial - T6 and below)

pyramidal decussation
3rd order: ventroposterolateral nucleus at the thalamus

Ends - post-central gyrus of the primary somatosensory cortex

Question 23

Describe UMN lesions clinically

Answer 23

UMN lesion - damage to neurons originating from brain cortices (internal capsule included) and spinal cord

Lesions: muscle wasting, hyper-reflexia, hypertonia, clonus and +ve Babinski sign

Question 24

Describe LMN lesions clinically

Answer 24

LMN lesion - damage to the anterior horn, nerve roots/plexus, peripheral nerves

Lesions: hypotonia/flaccid, hypo-reflexia, no clonus, prominent muscle wasting, fasciculations

Question 25

Distinctive features of cervical vertebrae

Answer 25

Bifid spinous process, 3x foramina (1 vertebral, 2 transverse - vertebral arteries). Thick discs relative to vertebral body. Articular facets - posterosuperior, anteroinferior

Question 26

Distinctive features of thoracic vertebrae

Answer 26

Long spinous processes projecting inferiorly. Articular facets for ribs are present; oriented posteriolateral and anteromedial. Thin discs relative to vertebral body

Question 27

Distinctive features of lumbar vertebrae

Answer 27

Largest vertebral bodies, thickest discs, large transverse processes. Articular facets are oriented medially and laterally.