Spine

Question 1

What do spinal nerves do

Answer 1

innervate different regions of the body below the head

emerge in pairs from between the vertebrae that make up the spinal column from superior to inferior

Question 2

what are the areas of the spinal column (from superior to inferior)

Answer 2

cervical region
thoracic region
lumbar region
sacral region

Question 3

Where do nerve fibers leave from in the spinal column

Answer 3

the ventral and dorsal aspects of the spinal column

Question 4

where does sensory information come from

Answer 4

dorsal aspect of the spinal column
dorsal root fibers = afferent

Question 5

where does motor information come from

Answer 5

ventral aspect of the spinal column
ventral foot fibers = efferent

Question 6

what are dermatomes

Answer 6

regions of the body that are served or innervated by a specific spinal nerve

represent the arrangement of cutaneous innervation zones or skin bands innervated by spinal afferents

Question 7

what cranial nerve carries sensory information from the face?

Answer 7

CN V: trigeminal

Question 8

What are the three synapses that make up the pathway to reach the somatosensory cortex

Answer 8

cuneate nucleus, thalamus, primary somatosensory cortex

Question 9

How does sensory information travel to the brainstem and then the cortices? (write the path)

Answer 9

FROM HAND:
Mechanoreceptor in the hand → Travel along the dorsal column of the spinal cord (traveling ipsilaterally) to enter the spinal column → travels along the tract until the first synapse towards the cuneate nucleus where they will synapse on a new set of cell bodies (medial lemniscus) → the axons of the cell bodies leave the cuneate nucleus and crossover/desscuate (contralateral representation of somatosensory information) → travel up to the thalamus where they will synapse on a new set of cell bodies (internal capsule) → new cluster of cell bodies sends their axons to primary somatosensory cortex

FROM FOOT:
Mechanoreceptor in the foot → causes an action potential to travel along the sensory part of the spinal nerve → axons enter the dorsal root of the spinal column and travel up the dorsal columns of the spinal column (gracile fasciculus) → axons synapse on a new set of cell bodies in the gracile fasciculus (ipsilateral) → their axons leave the cell bodies of the gracile nucleus and crossover/decussate and travel up along the medial lemniscus to synapse on the thalamus → their axons leave and travel along the internal capsule to synapse on new cell bodies in the primary somatosensory cortex