Ch. 13: The Spinal Cord, Spinal Nerves, and Spinal Reflexes

the *spinal cord* can be divided into __ segments

31

the *spinal cord* is a component of the ___

CNS

the *subarachnoid space* is filled with ___

CSF

the *dura mater* is *not attached* to the ____ _____ of the *vertebral column*

bony walls

just after passing through the *IVF*, a *spinal nerve* divides into ________

branches

________ ______: -*ventral rami* of *spinal nerve roots C1-C5* -supplies the *neck* ant parts of the *upper chest* and *shoulder*

cervical plexus

at *S2*, the *filum terminale* is now called the _________ ________

coccygeal ligament

the *coccygeal ligament* continues *inferiorly* to *anchor* at ______ _

coccyx 1

the *anterior and posterior gray horns* divide the *white matter* on *each side* into *three areas* called _______, with each area containing different *tracts*

columns (funiculi)

*spinal meninges* are __________ with the *cranial meninges*

continuous

the *spinal cord* ends at the _____ __________

conus medullaris

each ____ _______ gives rise to a pair of *spinal nerves*

cord segment

*superiorly*, the *spinal* dura mater is *continuous* with the *meningeal layer* of _______ ____ _____ at the *foramen magnum* of the *skull*

cranial dura mater

*spinal meninges* are *continuous* with the _______ ________

cranial meninges

each *spinal segment* is associated with a pair of ______ ___ _______ _____

dorsal and ventral roots

______ ____ ________: -an *enlarged* area of the *dorsal root* that contains *cell bodies* of *sensory neurons* -lies between the *pedicles* of *adjacent vertebrae*

dorsal root ganglion

______ ________: -small bundles of *axons* -arise from a single *dorsal root* (sensory) -enters the *spinal cord*

dorsal rootlets

______ _____: -contains *axons* of *sensory neurons* that conduct *sensory impulses* into the *CNS* -each one is associated with a *Dorsal Root Ganglion*

dorsal roots

____ _____ is the *outer layer* of the *spinal meninges*

dura mater

____ _____: -a single layer of tough *collagenous membrane* surrounded by *epidural space*

dura mater

at *S2*, the *filum terminale* pierces the *arachnoid mater* and becomes *invested* with the ____ _____

dura mater

the *ventral rami* of *spinal nerves T1-T11* are also known as ___________ __ ________ ______

intercostal or thoracic nerves

the *subdural space* contains ____________ _____

interstitial fluid

_______ ____ _____ contain: -*cell bodies* of *autonomic motor neurons* (*cardiac muscle, smooth muscle, and glands*)

lateral gray horns

the *coccygeal ligament* provides ____________ _______ to the *spinal cord*

longitudinal support

the *ventral rami* send *parasympathetic (S2-S4) visceral motor information* to form *pelvic splanchnic nerves* to _____ ______ ______

lower pelvic organs

*spinal nerves* are classified as _____ ______ because they contain *sensory and motor fibers*

mixed nerves

a _____ ______ is a complex of interwoven *nerve networks* that contain *sensory and motor fibers*

nerve plexus

the *pia mater* lies directly over the _____ _______ of the *spinal cord*

nerve tissue

the *spinal cord* can be divided into *31 segments* based on the _______ of the *spinal nerves*

origins

___________: coarse *connective tissue* that *bundles* axons into *fascicles*

perineurium

___ _____ is the *inner layer* of the *spinal meninges*

pia mater

___ _____: -a thin transparent *connective tissue* layer -adheres to the surface of the *spinal cord and brain*

pia mater

the *dorsal rami* have *no* ______ _________

plexus formation

_________ ____ ____ contain: -*cell bodies* of *interneurons* -*axons* of *somatic* and *autonomic sensory neurons* that enter the *cord* via *dorsal roots*

posterior gray horns

the *dura mater* is also connected via *numerous processes* to the _________ ____________ ________

posterior longitudinal ligament

the _________ ______ ______ is the *dorsal* groove of the *spinal cord*

posterior median sulcus

____ _____________: -contain *axons* associated with the *autonomic nervous system* -extends between the *ventral rami* and *sympathetic trunk ganglion*

rami communicantes

the *rami communicantes* is also known as the _____ ___________

ramus communicans

_____ are bundles of *axons* that connect each *spinal nerve* to a *segment* of the *spinal cord* by small bundles of *axons* called *rootlets*

roots

the *denticulate ligaments* help to ______ the *spinal cord*

secure

the *dorsal rami* receives *proprioception information* from the ________ _______ _______ ___ ______ of the *back*

skeletal muscles tendons and joints

the *dorsal rami* sends *visceral motor sympathetic nervous information* to the ____ of the *back*

skin (smooth muscles of blood vessels and glands)

the *dorsal rami* receives *sensory information* from the ____ ___ ________ _______ of the *back*

skin and skeletal muscles

the *subarachnoid space* being filled with *CSF* helps *protect* and *cushion* the ______ ____

spinal cord

______ ________ are *protective connective tissues* that encircle the *spinal cord*

spinal meninges

______ _____ ____: -the *union* of the *ventral* and *dorsal roots* within the *intervertebral foramen* -since a *spinal nerve* is formed by the merging of a *dorsal and sensory root*, it is classified as a *mixed nerve*

spinal nerve root

______ ______ __ -the *first* pair -exits the *vertebral canal* between the *occipital bone* and *atlas* (C1)

spinal nerves C1

______ ______ __ exit the *vertebral canal* between vertebrae *C7* and *T1*

spinal nerves C8

______ ______ _____ exit the *sacral canal* via the *4 pairs* of *sacral foramina*

spinal nerves S1-S4

______ ______ _____ ___ ___ *enter* the *sacral canal*

spinal nerves S1-S5 and Co1

______ ______ __ ___ ___ exit the *sacral canal* via the *sacral hiatus*

spinal nerves S5 and Co1

______ ______ _____ exit the *vertebral canal* *below* their *corresponding vertebrae*

spinal nerves T1-L5

the ____________ _____ is the space between the *arachnoid mater* and *pia mater*

subarachnoid space

the *ventral rami* of *spinal nerve T12* is also known as the _________ _____

subcostal nerve

the ________ _____ is a *narrow* space between the *dura mater* and *arachnoid mater*

subdural space

the *ventral rami* send *sympathetic (T1-L2) visceral motor information* to the *organs* of the ________ ___ ______________ ______

thoracic and abdominopelvic cavity

the *ventral rami* receive *visceral sensory (sympathetic T1-S2) information* from *organs* of the ________ ___ ______________ ______

thoracic and abdominopelvic organs

*lateral gray horns* are present *only* in ________ ___ ______ regions

thoracic and lumbar (T1-L2)

a _____ is a *bundle* of *axons* that carry the same type of information (sensory or motor) in the *same direction*

tract (fascicle or fasciculus)

_______ ________: -small bundles of *axons* -arise from the *spinal cord* -merge to form a single *ventral root* (motor)

ventral rootlets

_______ _____: -contains *axons* of *motor neurons* that conduct *motor impulses* to the *periphery* to control *somatic* and *visceral* effectors

ventral roots

*spinal nerves* are named according to the *region* and *level* of the _________ ______ from which they *emerge*

vertebral column

an *adult spinal cord* is about __ inches long

18

an *adult spinal cord* is about ___ inches wide

.55

*superiorly*, the *central canal* is *continuous* with the ___ _________ in the *medulla oblongata*

4th ventricle

*spinal nerves* are part of the ___

PNS

*filum terminale* and *denticulate ligments* ______ ___ ______ ____

anchor the spinal cord

________ ____ _____ contain: -*cell bodies* of *somatic motor neurons* whose *axons* exit the *cord* via *ventral roots*

anterior gray horns

the ________ ______ _______ is the *ventral* groove of the *spinal cord*

anterior median fissure

the *ventral rami* receive *proprioception information* from the *skeletal muscles, tendons, and joints* of the ________ _____ _______ _____ ___ ___________ ___________

anterior trunk lateral trunk and upper/lower extremities

the *ventral rami* receive *sensory information* from the *skin and skeletal muscles* of the ________ _____ _______ _____ ___ ___________ ___________

anterior trunk lateral trunk and upper/lower extremities

the *ventral rami* send *somatic motor information* to the *skeletal muscles* of the ________ _____ _______ _____ ___ ___________ ___________

anterior trunk lateral trunk and upper/lower extremities

the *ventral rami* send *sympathetic visceral motor information* to the *skin* of the ________ _____ _______ _____ ___ ___________ ___________

anterior trunk lateral trunk and upper/lower extremities

_________ _____ is the *middle layer* of the *spinal meninges*

arachnoid mater

_________ _____: -consists of 2 major components (membrane and trabeculae) -extends down to *S2*

arachnoid mater

arachnoid mater component: the _________ ________ is a thin layer of *connective tissue* in contact with the *dura mater*

arachnoid membrane

arachnoid mater component: the _________ __________ is a network of *collagen* and *elastic fibers* that extends from the *arachnoid membrane* to the outer surface of the *pia mater*

arachnoid trabeculae

the *width* of the *spinal cord* is *greater* in the ________ ___ ______ regions due to *spinal* nerves that emerge to supply the *upper* and *lower limbs*

cervical and lumbar

_____ ______: -the collection of *spinal nerve roots* from *L2* to the *1st coccygeal nerve* inferior to the *conus medullaris* -resembles a *horse's tail*

cauda equina

_______ _____: -a narrow *space* that contains *CSF* -extends the *entire* length of the *spinal cord*

central canal

the *dorsal rami* sends *somatic motor* information to ____ ________ _______ of the *back*

deep skeletal muscles

__________ _________: -extensions of *pia mater* that extend through the *arachnoid ater* to fuse with the *dura mater*

denticulate ligaments

a _________ is a specific *region* of the *skin* that provides *sensory input* to the *CNS* via a *single spinal nerve* or the *Trigeminal Nerve (CN V)*

dermatome

the *ventral rami* of *spinal nerves T2-T12* __ ___ ____ ________

do not form plexuses

___________: -loose *connective tissue* that wraps *individual axons*

endoneurium

________ __________ is utilized during *childbirth*

epidural anesthesia

________ _____: -space between the *vertebrae* and *spinal dura mater* -filled with *fat* and *blood vessels*

epidural space

__________: -a tough fibrous *connective tissue* that consists of *fibroblasts* and *collagen fibers* -covers the *entire nerve* -extends *deeply* to *fill* the spaces between the *fascicles* -blood vessels can penetrate to *supply* the *nerve*

epineurium

as the *spinal nerves* and their *roots* pass *laterally*, the *arachnoid and dura mater* fuse and become *continuous* with the __________ of the *spinal nerves*

epineurium

the *epidural space* is filled with ___ ___ _____ _______

fat and blood vessels

_____ _________: -a fine *connective tissue filament* closely united with the *pia mater* -extends from the *conus medullaris* -descends through the *vertebral canal* and *sacral canal* -*arachnoid mater* ends at *S2*

filum terminale

the *dura mater* is attached to the *circumference* of the _______ ______

foramen magnum

the *spinal cord* begins at the _______ ______

foramen magnum

____ ___________: -consists of *gray matter* -forms the *crossbar* of the *H* -connects the *gray matter* of the *right and left* sides of the *spinal cord* -the region where *axons* cross from *one side* of the *cord* to the *other* -encloses the *central canal*

gray commissures (anterior and posterior)

the ____ ____ _____________ reach *all spinal nerves*

gray rami communicantes

_____ ___________: -consist of *white matter* -the areas *anterior and posterior* to the *gray commissures* -connects the *white matter* of the *right and left* sides of the *spinal cord* -a region where *axons* cross from *one side* of the *cord* to the *other*

white commissures (anterior and posterior)

the _____ ____ _____________ reach *spinal nerves T1-L2*

white rami communicantes