Anatomy: CH 9: Spinal Cord and Meninges

An area of cell bodies within the CNS. Contains enlargements known as the dorsal horns (sensory) and the ventral horns (motor)

Gray matter of the spinal cord

An area of fibers (mainly axons) within the CNS. divided into posterior, lateral, and anterior funiculi.

White matter of the spinal cord

__________ are columns of nerve bundles containing tracts that course up and down, to and from the brain. This includes tracts like the corticospinal tract for voluntary movement

funiculi

Arises from the dorsal surface of the spinal cord. contains sensory neruons only

dorsal root

An enlarged portion of the dorsal root. contains cell bodies of sensory neurons

dorsal root ganglion

A ________ is defined as an area of cell bodies outside of the CNS.

ganglion

Arising from the ventral surface of the spinal cord. Contains axons of motor neurons only

ventral root

The ventral root joins with the dorsal root to form the ________. This divides into the ventral and dorsal rami

spinal nerve

The larger _____________ supplies the entire anterior trunk, as well as the appendages. This contains both sensory and motor neurons

ventral ramus

The smaller ___________ supplies structures of the back. This contains both sensory and motor neurons

dorsal ramus

Sensory neurons are also known as

afferent neurons

Motor neurons are also known as

efferent neurons

enable communication between sensory and motor neurons within the CNS

interneurons

The spinal cord is a long cylindrical mass of nervous tissue that occupies the upper __________ of the vertebral canal

two-thirds

The spinal cord is connected to the brain superiorly, where it is continuous with the medulla oblongata. It extends inferiorly to the level of ____________

LV2

The lower end of the spinal cord has a conical shape and is termed the ________

conus medullaris

The spinal cord presents enlargements in the cervical and lumbar regions, where the cell bodies of the neurons for the ____________ and _____________ are located

upper limb; lower limb

The cervical enlargement of the spinal cord is located from _______ to ________ spinal segments

CV5 to TV1

The lumbosacral enlargement of the spinal cord is located from the __________ to _________ spinal segments

LV1 to SV3

below the vertebral level of LV2, the vertebral canal is occupied by the __________

cauda equina

The cauda equina consists of the long roots of the lower spinal nerves and the ____________, which descend in a bundle from the conus medullaris

filum terminale

Because of the difference in length of the spinal cord and the vertebral canal, the level of attachment of the spinal root to the cord is _________ than the level of emergence of the spinal nerve

higher

At each segment, the dorsal root and the ventral root join to form the spinal nerve. There are __________ pairs of spinal nerves

31 pairs

The first pair of spinal nerves (C1) emerges between the ______ and the _________

atlas and skull

The C2 to C7 nerves emerge __________ the corresponding numbered vertebrae

above

The C8 pair emerges ___________ CV7

below

The remaining spinal nerves (T1-Cx1) emerge ________ the correspondingly numbered vertebrae

below

Number of nerve pairs in the cervical region:

8; C1-C8

Number of nerve pairs in the thoracic region:

12; T1-T12

Number of nerve pairs in the lumbar region

5; L1-L5

Number of nerve pairs in the sacral region

5; S1-S5

Number of nerve pairs in the coccygeal region

1; Cx1

Arteries supplying the spinal cord include one _____________ and two _____________

1) one anterior spinal artery

2) two posterior spinal arteries

The brain and spinal cord are surrounded and protected by three layers of connective tissue, collectively termed ____________

meninges

From external to internal, the meninges consist of:

1) dura mater

2) arachnoid mater

3) pia mater

The __________ is the outermost meninx. It is composed of dense, tough, fibrous connective tissue

dura mater

The dura of the spinal cord extends from the foramen magnum, where it is continuous with the dura mater that surrounds the brain down to the _____________ at SV2 and further to its inferior attachment to the coccyx called the ________________

dural sac; filum of the dura

The space external to the spinal dura mater is termed the _____________

epidural space

The epidural space contains _____________ in the form of globules of fat

adipose tissue

In addition to fat, the epidural space contains the _________________

vertebral venous plexus

The vertebral venous plexus, clinically referred to as ____________, connect superiorly with the dural sinuses of the cranial cavity

Batson's veins

Batson's veins communicate with veins external to the vertebrae via ___________.

intervertebral veins

Due to their close proximity, if an intervertebral vein becomes dilated it may compress a ______________

spinal nerve

The __________ is the intermediate meninx

arachnoid mater

The arachnoid mater is a delicate, loose, netlike membrane that surrounds the brain, courses, extends through the foramen magnum, through the vertebral column to ______

S2

The arachnoid mater is separated from the pia mater by the _____________, which is the space containing cerebrospinal fluid

subarachnoid space

The ____________ is the innermost layer of the meninges

pia mater

The pia mater is delicate connective tissue that adheres to the _________ of the brain and spinal cord

surface

The pia mater extends from the foramen magnum, where it is continuous with the _____________ inferiorly through the vertebral column to the end of the spinal cord, the conus medullaris, and further as an inferior extension

cerebral pia mater

There are two extensions of the pia mater:

1) denticulate ligament

2) filum terminale

The _____________ forms a series of toothlike lateral extensions of the pia from the lateral surface of the spinal cord

denticulate ligament

denticulate ligament: these extensions attach at intervals along the internal surface of the _______ and __________ of the cord

dura; arachnoid

Denticulate ligament: These extensions are made up of pia mater and are clinically important because they separate the _______ of the spinal nerves from __________

ventral roots; dorsal roots

In addition, a single inferior extension of the pia mater is found from the conus medullaris inferiorly through the vertebral column embedded within the roots of the cauda equina. This extension is called the ________________

filum terminale

The filum terminale attaches inferiorly at the _________

coccyx