spinal cord

dura mater

the tough outermost membrane enveloping the brain and spinal cord

arachnoid mater

a fine, delicate membrane, the middle one of the three membranes or meninges that surround the brain and spinal cord, situated between the dura mater and the pia mate

pia mater

the delicate innermost membrane enveloping the brain and spinal cord; like cling wrap

central canal

a hollow channel filled with cerebrospinal fluid (CSF), which provides mechanical protection and cushioning to the spinal cord, and helps in nutrient and waste transport to the nervous tissue within

dorsal horn

interneurons; sensory fibers; acts as the main relay and processing center for sensory information from the body, including touch, temperature, and pain

ventral horn

motor neurons; control voluntary muscle movements by housing motor neuron cell bodies that send signals to skeletal muscles, enabling contraction and movement

lateral horn

controls autonomic (involuntary) functions like heart rate and digestion by relaying commands from the brain to the sympathetic nervous system, preparing the body for stress or activity

dorsal root ganglion

sensory neurons; act as a relay station for incoming sensory signals from the body to the central nervous system

ventral root

carries motor signals from the central nervous system (brain and spinal cord) to the skeletal muscles

cervical plexus

serves the head, shoulders, neck, and diaphragm

phrenic nerve

diaphragm

brachial plexus

serves the arms, chest, and shoulders

radial nerves

arm, forearm, wrist

ulnar nerves

flexor carpi radialis

lumbar plexus

serves the anterior lower limbs

femoral nerve

anterior thigh

sacral plexus

serves the posterior lower limbs

sciatic nerve

posterior thigh

spinal cord is a continuation of the brain stem

medulla oblangata

foramen magnum

most superior boundary of the spinal cord

conus medullaris

spinal cord terminus

what is a lumbar puncture?

medical procedure that involves inserting a needle into the lower back to collect cerebrospinal fluid (CSF). 

where can you do a lumbar puncture?

between L3/L4 or L4/L5

why can you do a lumbar puncture below L3

the spinal cord ends at L2 so there is a lesser chance of of damaging it

filum terminale

meningeal extension beyond the spinal cord terminus

cauda equina

collection of spinal nerves traveling in the vertebral canal below the terminus of the spinal cord

cervical nerves

C1-C8

thoracic nerves

T1-T12

lumbar nerves

L1-L5

sacral nerves

S1-S5

coccygeal nerves

taibone; 31st and final pair