Anatomy and Physiology Exam Review
(Newest material) Updated Fall
2024/2025.
Characteristics of the Spinal Cord
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?
Cell bodies
What are the two spinal roots of the PNS?
Dorsal (sensory) roots and ventral (motor) roots
What are the three spinal cord horns (gray matter)?
dorsal horns
ventral horns
lateral horns
Describe dorsal horns.
Sensory pathway cell bodies
Describe ventral horns.
Motor pathway cell bodies
Describe lateral horns.
Sympathetic motor cell bodies
What are the variations in internal structures?
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?
Myelinated axon tracts headed in the same direction
divided into ascending and descending tracts
What are Ascending tracts?
carries sensory information upward
mainly dorsal and superficial
, What are descending tracts?
carries motor information downward
mainly ventral and deep
List the three Ascending pathways.
Posterior column
Spinothalamic tracts
Spinocerebellar tracts
What do posterior columns consist of?
Touch, vibration, and proprioception to the cerebrum
Lower body information medially and upper body laterally
3 neurons
Characteristics of Spinothalamic tracts.
pain and temperature to the brain
Characteristics of spinocerebellar tracts.
proprioceptive feedback to cerebellum
What are the three basic somatic sensory pathways?
First order neurons
second order neurons
third order neurons
Describe the first order neurons (pseudounipolar).
sensory receptor to spinal cord or brainstem
cell bodies lie in DRG
Describe the second order neurons (multipolar).
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).
Thalamus to cerebral cortex
Cell bodies in thalamus
What is the primary sensory cortex?
the cerebral region that begins processing general senses
Parts of the primary sensory cortex.
Somatotopic map
Sensory homunculus
What is somatotopic map?
each body region has a dedicated region of the primary sensory cortex, from head to toes
(Newest material) Updated Fall
2024/2025.
Characteristics of the Spinal Cord
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?
Cell bodies
What are the two spinal roots of the PNS?
Dorsal (sensory) roots and ventral (motor) roots
What are the three spinal cord horns (gray matter)?
dorsal horns
ventral horns
lateral horns
Describe dorsal horns.
Sensory pathway cell bodies
Describe ventral horns.
Motor pathway cell bodies
Describe lateral horns.
Sympathetic motor cell bodies
What are the variations in internal structures?
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?
Myelinated axon tracts headed in the same direction
divided into ascending and descending tracts
What are Ascending tracts?
carries sensory information upward
mainly dorsal and superficial
, What are descending tracts?
carries motor information downward
mainly ventral and deep
List the three Ascending pathways.
Posterior column
Spinothalamic tracts
Spinocerebellar tracts
What do posterior columns consist of?
Touch, vibration, and proprioception to the cerebrum
Lower body information medially and upper body laterally
3 neurons
Characteristics of Spinothalamic tracts.
pain and temperature to the brain
Characteristics of spinocerebellar tracts.
proprioceptive feedback to cerebellum
What are the three basic somatic sensory pathways?
First order neurons
second order neurons
third order neurons
Describe the first order neurons (pseudounipolar).
sensory receptor to spinal cord or brainstem
cell bodies lie in DRG
Describe the second order neurons (multipolar).
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).
Thalamus to cerebral cortex
Cell bodies in thalamus
What is the primary sensory cortex?
the cerebral region that begins processing general senses
Parts of the primary sensory cortex.
Somatotopic map
Sensory homunculus
What is somatotopic map?
each body region has a dedicated region of the primary sensory cortex, from head to toes
