ACTUAL EXAM COMLETE 200 QUESTIONS ND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY
GRADED A
Characteristics of the Spinal Cord - ANSWER: Spans from foramen magnum to L1
17 inches long and 3/4 inches thick
Major somatic and autonomic reflex center
communication center between brain and body
connected to PNS via 31 paired spinal nerves
what is the dorsal root ganglion? - ANSWER: Cell bodies
What are the two spinal roots of the PNS? - ANSWER: Dorsal (sensory) roots and
ventral (motor) roots
What are the three spinal cord horns (gray matter)? - ANSWER: dorsal horns
ventral horns
lateral horns
Describe dorsal horns. - ANSWER: Sensory pathway cell bodies
Describe ventral horns. - ANSWER: Motor pathway cell bodies
Describe lateral horns. - ANSWER: Sympathetic motor cell bodies
What are the variations in internal structures? - ANSWER: cervical and lumbar
enlargements
more white matter superiorly and less inferiorly (most pass through neck)
lateral horns found only in thoracolumbar regions
What is white matter in the spinal cord? - ANSWER: Myelinated axon tracts headed
in the same direction
divided into ascending and descending tracts
What are Ascending tracts? - ANSWER: carries sensory information upward
mainly dorsal and superficial
What are descending tracts? - ANSWER: carries motor information downward
mainly ventral and deep
List the three Ascending pathways. - ANSWER: Posterior column
Spinothalamic tracts
Spinocerebellar tracts
, What do posterior columns consist of? - ANSWER: Touch, vibration, and
proprioception to the cerebrum
Lower body information medially and upper body laterally
3 neurons
Characteristics of Spinothalamic tracts. - ANSWER: pain and temperature to the brain
Characteristics of spinocerebellar tracts. - ANSWER: proprioceptive feedback to
cerebellum
What are the three basic somatic sensory pathways? - ANSWER: First order neurons
second order neurons
third order neurons
Describe the first order neurons (pseudounipolar). - ANSWER: sensory receptor to
spinal cord or brainstem
cell bodies lie in DRG
Describe the second order neurons (multipolar). - ANSWER: Spinal cord to a sorting
center in the thalamus or cerebellum
Cell bodies in gray matter of spinal cord or medulla
Describe the third order neurons (multipolar). - ANSWER: Thalamus to cerebral
cortex
Cell bodies in thalamus
What is the primary sensory cortex? - ANSWER: the cerebral region that begins
processing general senses
Parts of the primary sensory cortex. - ANSWER: Somatotopic map
Sensory homunculus
What is somatotopic map? - ANSWER: each body region has a dedicated region of
the primary sensory cortex, from head to toes
What is the sensory homunculus? - ANSWER: represents the proportion of sensory
neurons in each body region
What are the three somatic sensory pathways? - ANSWER: posterior column tracts
spinothalamic tracts
spinocerebellar tracts
What role do the basic somatic sensory pathways play in the posterior column
tracts? - ANSWER: 1st order neuron: stimuli causes AP through nerve and ascends in
posterior column. Decussates in medullary
2nd neuron (crosses sides): ascends to synapse in thalamus
3rd neuron: delivers signal to sensory cortex