ch 13- sec 1
posterior root ganglion
a swelling that contains the cell bodies of the sensory nerve
transmit nerve impulses to and from brain and house the spinal reflexes
2 functions of the spinal cord
meninges
3 layers of specialized membranes surrounding the brain and spinal cord.
dura, arachnoid, pia
3 layers of the meninges
dura mater
The most superficial layer of connective tissue, composed of dense irregular ct
arachnoid mater
avascular middle meninx; arrangement of collagen and elastic fibers
roots
bundles of axons that connect each spinal nerve to a segment of the nerve
conus medullaris
conical tapering of sc
subdural/subarchnoid space
contains csf/ interstitial fluid
posterior (dorsal) root
contains only sensory axons
cranial meninges
encircle the brain
rootlets
even smaller bundles of axons
Filum terminate
extension of pia mater that helps anchor cord in place
denticulate ligaments
extensions of the pia mater that anchor the sc
lumbar enlargement
in the lower back, t9- t12, a thickening in the spinal cord; gives off nerves to lower limbs
cervical enlargement
in the neck region, c4- t1, a thickening in the spinal cord; supplies nerves to upper limbs
pia mater
innermost meninx composed of ct; contains bv that supply oxygen and nutrients
csf
serves as shock absorber and suspension system
epidural space
space between sc and the vertebral canal
roots and rootlets
spinal nerves are composed of (2)
spinal meninges
surround the spinal cord
cauda equina
the lumbar, sacral and coccygeal nerves descend beyond the end of the cord, forming a structure called ______________ (horses tail)
medulla oblongata
the spinal cord begins at the ______ and terminates between the 1st and 2nd lumbar vertebrae
31
the spinal cord consists of ______ segments, each of which gives rise to a pair of spinal nerves
spinal nerves
these nerves connect the cns to pns