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
