Spinal Cord Flashcards
spinal cord extends from
foramen magnum to second lumbar vertebrae
spinal cord produces responses through
reflex mechanisims
spinal nerves exit vertebral column through
intervertebral and sacral foremina
spinal nerve is
bundle of axons
shwann cells
connective tissue sheath
spinal cord is _______ in diameter are superior end and _______at inferior end
larger; smaller
How many pairs of spinal nerves are there
31
cervical enlargement
inferior cervical region
nerves supply upper limbs
lumbosacral region
inferior thoracic, lumbar and superior sacral region
supplies lower limbs
conus medullaris
cone like region immediately inferior to lumbosacaral region
tip is inferior end of spinal cord
cauda equina
origin of spinal nerves from lumbosacral and conus medullaris
resembles a horses tail
superficial to deep layers of meninges and their spaces (6)
- epidural space
- dura mater
- subdural space
- arachnoid matter
- subarachnoid space
6.pia matter
epidural space
between bone and dura matter
location of epidural anesthesia
contains blood vessels, areolar connective tissue and fat
dura mater
thickest membrane
forms sac called thecal sac
continuous with dura of brain and epinerium spinal nerves
thecal sac
sac around vertebral cord
starts at foramen magnum and ends at 2nd sacral vert
arachnoid mater
very thin and delicate
subdural space
between arachnoid space and dura space
contains small amount of serous fluid
subarachnoid space
between arachnoid and pia matter
contains network or arachnoid mater, blood vessels and CSF
pia matter
bound very tightly to spinal cord
denticulate ligament
connective tissue septa extending from lateral side of spinal cord to dura matter to help limit lateral movement
attaches to spinal cord by TOOTH like processes
filum terminale
connective tissue strand that limits superior movement of spinal cord
anchors conus medullaris and thecal sac to first coccygeal vert
superficial portion of cord is ______mater and _________ is deep
white; gray
white mater made of
myelinated axons called Tracts
white matter divided into 3 columns called
- ventral
- drosal
- lateral
each column is divided into
tracts; pathways
can be ascneding (towards brain)
or descending (away from brain)
gray matter is made of
neuron cell bodies, dendrites and axons
gray matter is divided into 3 HORNS called
- anterior (ventral)
- Posterior (dorsal)
3.lateral (associated with ANS)
Anetiror median fissure and posteiror suculus
two deep clefts partially separating the two halves of spinal cord
gray and white commissures
contain axons that cross from one side of spinal cord to another
connects left and right halves
central canal
inside the gray commissure
helps circulate CSF of the ventricles
spinal nerves arise as ____ and combine to become ____
rootlets; roots
ventral root
axons of motor neurons
innervates muscles and glands
axons pass into spinal nerves
ventral HORN
cell bodies of multipolar somatic neurons
called motor horn
dorsal root
axons of SENSORY neurons
axons pass into dorsal horn to synapse with interneurons
or pass into white matter to tracts
dorsal root ganglia
cell bodies of sensory neurons
psuedo unipolar
ventral root and dorsal root combine to form
spinal nerve
