731 Foundational Neuroanatomy: The Spinal Cord

how many cervical spinal segments are there

8

how many thoracic spinal segments are there

12

how many lumbar spinal segments are there

5

how many sacral spinal segments are there

5

how many coccygeal spinal segments are there

1

cervical enlargement

C4-T1 nerves supporting the upper limb

lumbar enlargement

T9-T12 nerves serving lower limb

meninges

a set of 3 protective layers that surround the brain and spinal cord

dura mater

the outermost and toughest layer of the meninges

meningeal layer

the inner layer of the dura mater that covers the brain and spinal cord

arachnoid mater

the delicate layer that lies beneath the dura mater

subdural space

the space between the dura mater and the arachnoid mater

subarachnoid space

the space between the arachnoid matter and the pia matter that contains CSF

pia matter

the thin, delicate layer that adheres to the surface of the brain and spinal cord

anterior (ventral) horn

contains cell bodies of motor neurons that send signals to skeletal muscles and are responsible for initiating voluntary movements and controlling muscle tone

posterior (dorsal) horn

contains cell bodies of interneurons and the terminations of sensory neurons responsible for processing incoming sensory info and before transmitting the processed information to the brain

lateral horn

only in thoracic lumbar segments and contains cell bodies of preganglionic sympathetic neurons which are involved in the autonomic nervous system

gray commissure

thin band of gray matter that connects the left and right sides of the spinal cords and contains CSF and plays a role in transmitting nerve signals across the spinal cords midline

posterior gray matter horn

sensory

anterior gray matter horn

somatic motor

lateral gray matter horn

autonomic motor

anterior white column

contains both ascending and descending tracts

contains anterior corticospinal tract

lateral white column

contains a mix of ascending and descending tracts

contains lateral corticospinal tract

contains spinothalamic tract

posterior white column

contains primarily ascending tracts such as dorsal column medial leminscus