anatomy of back region
TRANSCRIPT
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Arteries of the Back
Artery Source Branches Supply to Notes
anteriorradicular
they arise asmultiple
branches ofseveral vessels
(vertebral,
posterior
intercostal,lumbar, and
lateral sacral
aa.)
they accompanythe ventral rootlets
to reach the spinalcord
meninges;spinal cord;
spinal nerve;ventral rootlets
anterior radicularaa. anastomose
with the anteriorspinal a.
anterior spinal contributionsreceived fromseveral arteries
(vertebral,
posterior
intercostal,subcostal,
lumbar, lateral
sacral aa.)
pial arterial plexus meninges;spinal cord;medulla (dorsal
motor nucleus
of cranial nerve
X, nucleusambiguus,
spinal accessory
nucleus andhypoglossal
nucleus)
anterior spinal a.anastomoses withthe anterior
radicular brs. of
the spinal rami of
the vertebral,posterior
intercostal,
subcostal, lumbarand lateral sacral
aa.
axillary subclavian a.(axillary a. is
the continuationof the
subclavian
lateral to the 1strib)
1st part: superiorthoracic a.; nd
part:thoracoacromial a.,
lateral thoracic a.;
!rd part: anteriorhumeral circumflex
a., posterior
humeral circumflex
a., subscapular a.
pectoral region,shoulder region
and upper limb
pectoralis minorm. crosses
anterior to theaxillary artery
and is used to
delineate the !parts mentioned
at left
cervical,ascending
inferior thyroida.
unnamed muscularbranches
deep muscles ofthe nec"
ascendingcervical a.ascends on the
anterior surface
of the anterior
scalene m. besidethe phrenic n.
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cervical, deep costocervicaltrun"
unnamed muscularbranches
deep muscles ofthe posterior
nec"
deep cervical a.anastomoses with
the occipital a.
near the occipitalbone
cervical,
transverse
thyrocervical
trun"
unnamed muscular
branches, possiblythe dorsal scapular
a.
trape#ius muscle
and surroundingtissues
transverse
cervical a. givesrise to the dorsal
scapular a. $!%&
of the time
costocervical
trun"
subclavian a.,
nd part
deep cervical a.,
highest intercostala.
deep muscles of
the posteriornec"; posterior
ends of the first
intercostalspaces
costocervical
trun" is locatedbetween the
anterior scalene
m. and the middlescalene m.; it
arches posteriorly
over the cervicalparietal pleura
deep cervical costocervical
trun"
unnamed muscular
branches
deep muscles of
the posteriornec"
deep cervical a.
anastomoses withthe occipital a.
near the occipital
bone
dorsalscapular subclavian a.,!rd part unnamed muscularbranches levator scapulaem.,rhomboideus
ma'or m.,
rhomboideusminor m.
dorsal scapular a.anastomoses withthe suprascapular
a. and the
subscapular a. toform the scapular
anastomosis;
dorsal scapular a
is a branch of thetransverse
cervical a. in
$!%& of casesgreat anterior
radicular
the spinal br. of
the lower
posteriorintercostal a.,
subcostal a., or
upper lumbar a.,
no named branches lower spinal
cord
great anterior
radicular a.
anastomoses withthe anterior spinal
a. at lower
thoracic or upper
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usually on left lumbar spinalcord levels
intercostal,posterior
highestintercostal
(upper intercostal
spaces),descending
thoracic aorta
(!rd11thintercostal
spaces)
posterior br., spinalbr., anterior br.,
collateral br.,lateral cutaneous
br.
intercostalmuscles, spinal
cord andvertebral
column, deepbac" muscles,
s"in and
superficialfascia overlying
the intercostal
spaces
posteriorintercostal aa.
supply the lateraland posterior
portions of theintercostal space;
anterior
intercostal aa.supply the
anterior portions
of the intercostalspaces
lateral sacral internal iliac a.,posterior
division
spinal brs. sacrum, sacralnerve rootlets,
meninges,
ad'acentmuscles
there are usually lateral sacral aa.
on each side, a
superior one andan inferior one
lumbar abdominal aorta anterior br.,
posterior br., spinalbr.
psoas ma'or m.,
psoas minor m.,uadratus
lumborum m.,
spinal cord andvertebral
column, deepbac" muscles
the * lumbar
arteries on eachside arise from
the posterior
surface of theaorta at the level
of vertebrae +1+*; they course
posterior to thepsoas ma'or m.
median sacral abdominal aorta th lumbar aa. sacrum median sacral a.
appears to be the
continuation of
the abdominalaorta in the
median plane,
although it ismuch smaller in
si#e
posteriorradicular
they arise asmultiple
branches of
several vessels
no named branches meninges;spinal cord;
spinal nerve;
dorsal rootlets
posteriorradicular aa.
accompany the
dorsal rootlets;
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(vertebral,posterior
intercostal,
lumbar, andlateral sacral
aa.)
they anastomosewith the posterior
spinal aa.
posteriorspinal
contributionsreceived from
several arteries
(posteriorinferior
cerebellar,
vertebral,posterior
intercostal,
subcostal,lumbar, lateralsacral aa.)
pial arterial plexus spinal cord,especially the
dorsal columns;
medulla(nucleus
cuneatus and
nucleus gracilis)
paired; posteriorspinal aa.
anastomose with
the posteriorradicular brs. of
the spinal rami of
the vertebral,posterior
intercostal,
subcostal, lumbarand lateral sacralaa.
radicular,
anterior
they arise as
multiple
branches of
several vessels(vertebral,
posterior
intercostal,lumbar, and
lateral sacral
aa.)
they accompany
the ventral rootlets
to reach the spinal
cord
meninges;
spinal cord;
spinal nerve;
ventral rootlets
anterior radicular
aa. anastomose
with the anterior
spinal a.
radicular,
great anterior
the spinal br. of
the lower
posteriorintercostal a.,
subcostal a., or
upper lumbar a.,usually on left
no named branches lower spinal
cord
great anterior
radicular a.
anastomoses withthe anterior spinal
a. at lower
thoracic or upperlumbar spinal
cord levels
radicular,
posterior
they arise as
multiple
branches ofseveral vessels
(vertebral,
posterior
intercostal,
no named branches meninges;
spinal cord;
spinal nerve;dorsal rootlets
posterior
radicular aa.
accompany thedorsal rootlets;
they anastomose
with the posterior
spinal aa.
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lumbar, andlateral sacral
aa.)
sacral, lateral internal iliac a.,
posteriordivision
spinal brs. sacrum, sacral
nerve rootlets,meninges,
ad'acentmuscles
there are usually
lateral sacral aa.on each side, a
superior one andan inferior one
sacral, median abdominal aorta th lumbar aa. sacrum median sacral a.appears to be the
continuation of
the abdominalaorta in the
median plane,
although it ismuch smaller in
si#e
scapular,circumflex
subscapular a. unnamed muscularbranches
teres ma'or m.,teres minor m.,
infraspinatus m.
circumflexscapular a.
anastomoses with
the suprascapulara. and the dorsal
scapular a. to
form the scapularanastomosis
scapular,dorsal
subclavian a.,!rd part
unnamed muscularbranches
levator scapulaem.,
rhomboideus
ma'or m.,rhomboideus
minor m.
dorsal scapular a.anastomoses with
the suprascapular
a. and thesubscapular a. to
form the scapular
anastomosis;
dorsal scapular ais a branch of the
transverse
cervical a. in$!%& of cases
spinal,
anterior
contributions
received fromseveral arteries
(vertebral,
posterior
pial arterial plexus meninges;
spinal cord;medulla (dorsal
motor nucleus
of cranial nerve
the anterior spinal
a. anastomoseswith the anterior
radicular brs. of
the spinal rami of
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intercostal,subcostal,
lumbar, lateral
sacral aa.)
X, nucleusambiguus,
spinal accessory
nucleus andhypoglossal
nucleus)
the vertebral,posterior
intercostal,
subcostal, lumbarand lateral sacral
aa.
spinal,posterior
contributionsreceived from
several arteries
(posteriorinferior
cerebellar,
vertebral,posterior
intercostal,
subcostal,lumbar, lateralsacral aa.)
pial arterial plexus spinal cord,especially the
dorsal columns;
medulla(nucleus
cuneatus and
nucleus gracilis)
paired; posteriorspinal aa.
anastomose with
the posteriorradicular brs. of
the spinal rami of
the vertebral,posterior
intercostal,
subcostal, lumbarand lateral sacralaa.
thoracodorsal subscapular a. unnamed muscular
branches
latissimus dorsi
m.
thoracodorsal a.
accompanies the
thoracodorsal n.
transverse
cervical
thyrocervical
trun"
unnamed muscular
branches, possibly
the dorsal scapulara.
trape#ius muscle
and surrounding
tissues
transverse
cervical a. gives
rise to the dorsalscapular a. $!%&
of the time
trun",
costocervical
subclavian a.,
nd part
deep cervical a.,
highest intercostal
a.
deep muscles of
the posterior
nec"; posteriorends of the first
intercostal
spaces
costocervical
trun" is located
between theanterior scalene
m. and the middle
scalene m.; it
arches posteriorlyover the cervical
parietal pleura
trun",thyrocervical
subclavian a.,1st part
inferior thyroid a.,transverse cervical
a., suprascapular a.
lower nec",posterior
shoulder,
thyroid gland
thyrocervicaltrun" does not
give rise to the
ascendingcervical a. it is a
branch of the
inferior thyroid a.
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vertebral subclavian a.(1st part)
spinal brs.,muscular brs.,
anterior spinal a.,
posterior inferiorcerebellar a.,
medullary brs.,meningeal brs.,basilar a.
deep nec",cervical spinal
cord, spinal
cord; medulla(dorsal motor
nucleus ofcranial nerve X,nucleus
ambiguus,
spinal accessory
nucleus andhypoglossal
nucleus)
vertebral a.anastomoses with
the internal
carotid a. in thecerebral arterial
circle (of -illis);it courses throughthe transverse
foramina of
vertebrae 1/
Bones of the Back Region - Listed in Superior to Inferior
Order
Bone Structure Description Notes
occipital
the bone forming the
posterior surface of
the s"ull
it articulates superolaterally with
the parietal bones through the
lambdoid suture, anteroinferiorlywith the temporal bone and
anteriorly with the body of the
sphenoid bone
external
occipital
protuberance
a low process on the
external surface of the
occipital bone in the
it is an attachment site for the
ligamentum nuchae; the superior
nuchal lines of the two sides meet
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midline in the midline at the externaloccipital protuberance; also "nown
as: inion
inferior nuchal
line
a low ridge that runs
transversely on theexternal surface of the
suamous part of theoccipital bone inferior
to the superior nuchal
line
it is an attachment site for deep
nec" muscles
superior nuchal
line
a low ridge that runs
transversely on theexternal surface of the
suamous part of the
occipital bone
it is an attachment site the for the
trape#ius and splenius mm.
occipital
condyle
a low, wide pro'ection
from the inferior
surface of the lateralpart of the occipital
bone
paired; it articulates with the atlas
vertebra one of a series of
irregular bones that
form the spine
a vertebra has two parts: the
vertebral body and the vertebral
arch; there are !! vertebrae total: 0cervical, 1 thoracic, lumbar,
fused to form the sacrum, *coccygeal; features of a typicalvertebra include: body, pedicles,
transverse processes, laminae,
articular processes, spinous process
vertebral body the largest part of the
vertebra
it is shaped li"e a short cylinder;
ad'acent vertebral bodies articulate
through a symphysis
vertebral arch the ring of bone
formed by the paired
pedicles and pairedlaminae of the
vertebra
the transverse processes and
spinous process are attached to the
neural arch; the neural arch protectsthe spinal cord
pedicle short strong process
that extends
posteriorly from theposterolateral surface
paired; it connects the body with
the transverse process; it is mar"ed
by superior inferior vertebralnotches;
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of the vertebral body
transverse
process
a lateral process the
extends from the'unction of the pedicle
and the lamina of thevertebra
a site for muscle attachment and rib
articulation
lamina a broad flat plats of
bone located between
the transverse processand the spinous
process of the vertebra
paired; it is flattened mar"edly in
the anteroposterior direction;
ligamenta flava span the intervalbetween the laminae of ad'acent
vertebrae
articular
processes
processed that pro'ect
inferiorly and
superiorly from the
'unction of the laminaand pedicle of the
vertebra
two pair on each vertebra (superior
and inferior); the superior articular
processes of one vertebra articulate
with the inferior processes of thead'acent vertebra through synovial
'oints
intervertebral
notch
a notch on the
superior and inferiorsurface of the
vertebral pedicle
the superior intervertebral notch of
one vertebra combined with theinferior intervertebral notch of the
ad'acent vertebra forms the
intervertebral foramen
intervertebral
foramen
an opening between
the pedicles of
ad'acent vertebrae
ad'acent intervertebral notches form
the intervertebral foramen; an
opening for passage of the spinalnerve
vertebral canal the opening formed bythe combination of the
body and the vertebral
arch
it contains the spinal cord,meninges, epidural fat and the
internal vertebral plexus of veins
spinous process a posterior midline
process arising from
the 'unction of the two
laminae of thevertebra
it pro'ects downward and inferiorly;
it is an important site of muscle
attachment; spinous processes of
cervical vertebra / are bifid
cervical
vertebrae
the seven vertebrae of
the nec"
cervical vertebrae have the features
of the typical vertebra plus all have
transverse foramina (for passage ofthe vertebral artery); / have
bifid spinous processes; cervical
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vertebrae have relatively smallbodies; several cervical vertebra are
named: atlas, axis, vertebra
prominens
atlas (1) the first cervicalvertebra it is called atlas in comparison the
mythological 2ree" 3itan 4tlas,
who bore the weight of the worldon his shoulders; it has no vertebral
body, only anterior posterior
arches; it articulates with the
odontoid process of the axis
axis () the second cervicalvertebra
the odontoid process (dens) pro'ectssuperiorly from its body; it
articulates with the anterior arch of
the atlas
vertebraprominens
the seventh cervicalvertebra
it has a long, nonbifid spinousprocess which is prominent at the
nape of the nec", hence its name
thoracic
vertebrae
the 1 vertebrae
associated with the
thoracic region
thoracic vertebrae have the features
of a typical vertebra plus they are
characteri#ed by long slender spinesthat pro'ect inferiorly; they have
facets for articulation with ribs;thoracic vertebrae have bodies ofintermediate si#e
costal articular
facet on thebody
small smooth areas at
the 'unction of thebody and the vertebral
arch
most thoracic vertebrae have
costal facets on each side (onesuperior and one inferior); the
superior costal facet of one vertebra
and the inferior costal facet of thead'acent vertebra both articulate
with the head of the same rib; also
"nown as demifacets
costal articular
facet on thetransverse
process
a small smooth area
on the transverseprocess of the thoracic
vertebra
it articulates with the articular facet
on the tubercle of the rib
lubar the vertebrae located lumbar vertebrae have the features
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vertebrae in the lumbar region of a typical vertebra plus they arecharacteri#ed by short, blunt spines
that pro'ect posteriorly; lumbar
spines do not overlap ma"ing thelumbar level a good one for spinal
tap; lumbar vertebrae are builtstrong and have the largest bodiesof all vertebrae
sacru a triangular bone that
is the posteriors"eletal element
forming the pelvis
it is formed by fused vertebrae;
the sacrum and two os coxae bonesform the pelvis
anterior sacral
foramina
an opening in the
anterior surface of the
sacrum
there are four pairs; each transmits
the ventral primary ramus of the
respective sacral spinal nerve;branches of the lateral sacral aa.
enter the sacral canal through these
openings
posterior sacral
foramina
an opening in the
posterior surface of
the sacrum
there are four pairs; each transmits
the dorsal primary ramus of the
respective sacral spinal nerve
promontory a pro'ection of the
superior part of thesacrum in an anterior
direction
the body of the fifth lumbar
vertebra sits on the sacralpromontory and articulates with it
through a symphysis
sacral canal the opening in the
center of the sacrum
it is the continuation of the
vertebral canal at sacral vertebral
levels
articular surface the roughened area
located on the lateralsurface of the sacrum
this surface articulates with the
ilium in the sacroiliac articulation
body the central portion of
the sacrum
the body is euivalent to the bodies
of the other vertebra
base the superior surface ofthe sacrum
the base of the sacrum articulateswith the fifth lumbar vertebrathrough an intervertebral dis"
sacral hiatus an opening in theposterior surface of
the sacrum in the
midline
it is a normal feature that resultsfrom the failure of fusion of the
laminae of the fifth sacral segment
(and sometimes the fourth) during
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development
ala the lateral portion of
the sacrum
paired; it pro'ects laterally from the
body of the sacrum; it representsthe fused costal and transverse
processes of the first sacral vertebra
coccy! the most inferior
portion of the
vertebral column
the coccyx results from the fusion
of the four coccygeal vertebrae; it
may be a single bone or the first
coccygeal vertebra may beseparated from the other three; it
articulates with the fifth sacral
segment; coccygeal vertebrae arereduced in complexity, having no
pedicles, laminae or spines
"asciae of the Back Region - Arranged Alphabetically
Structure Location#Description Notes
fascia,
infraspinatus
deep fascia covering the
superficial surface of theinfraspinatus m.
infraspinatus fascia attaches to the spine
of the scapula and the posterior surface ofthe scapula at the margins of the
infraspinatus fossa; it is a strong origin
for the infraspinatus m.
fascia, nuchal deep fascia covering the
muscles of the posterior nec"
nuchal fascia is part of the prevertebral
layer of deep cervical fascia
fascia,
thoracolumbar
deep fascia surrounding the
erector spinae muscle mass
thoracolumbar fascia in lumbar regions
serves as an origin for the latissimusdorsi m.
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$oints and Ligaents of the Back Region - Listed
Alphabetically
$oint or
ligaentDescription Notes
anteriorlongitudinal
ligament
a ligament that courses fromsuperior to inferior along the
anterior surfaces of allvertebral bodies
it lies directly posterior to the thoracicand abdominal viscera
interspinous
ligament
a ligament that connects the
spinous processes of two
ad'acent vertebra
a syndesmosis
intervertebral a fibrocartilaginous dis" a symphysis; it is composed of two
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disc between ad'acent vertebralbodies
parts: an outer anulus fibrosus and aninner nucleus pulposus; the nucleus
pulposus is the remnant of the
notochord; the intervertebral dis"s areimportant shoc" absorbers between
vertebrae
ligamenta flava a ligament formedpredominantly by elastic fibers
which 'oins the laminae of
ad'acent vertebrae
a syndesmosis; paired; the ligamentumflavum is penetrated by the needle
during spinal tap; the word flavum is
derived from the +atin word flavus,which means 5yellow5 a reference to
the predominance of yellow elastic
fibers which gives this ligament itsgrossly visible color
nuchal ligament a midline ligament that extendsposteriorly from the spinous
processes of cervical vertebrae
and extends from the base ofthe s"ull to the 0th cervical
vertebra
a syndesmosis; it provides muscleattachments to the cervical spinous
processes without the necessity of long
spinous processes that would hinderextension of the nec"
posteriorlongitudinal
ligament
a ligament that courses fromsuperior to inferior along the
posterior surfaces of all
vertebral bodies
it is broader at the intervertebral dis"sand narrow at the vertebral bodies
which gives it a scalloped edge; it is
located in the vertebral canal; it is 673penetrated by the needle during spinal
tap
supraspinous
ligament
a ligament that connects the
tips of the spinous processes of
thoracic and lumbar vertebrae
a syndesmosis; the supraspinous
ligament begins at the 0 vertebra and
ends at the midsacral segmental level;it serves as a muscle attachment site
#ygapophyseal
'oint
a small 'oint between the
articular processes of ad'acentvertebrae
a synovial plane 'oint
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Note: Although the back and extremities contain numerous lymphaticcapillaries, within these regions there are very few lymph nodesthat are large enough to be named.
Lyphatics of the Back - Listed Alphabetically
Structure LocationAfferents
fro
%fferents
to
Regions
drainedNotes
occipitalnodes
superiornuchal line,
along the
course of
lymphaticvessels from
the posterior
head and
accessorynodes
occipitalpart of the
scalp and
the
occipital nodes are or !nodes located between
the attachments of the
sternocleidomastoid m.
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the occipitala. and v.
nec" superiornec"
and the trape#ius m.
&uscles of the 'pper Lib that are dissected in the
Back Region
&uscle Origin Insertion Action Innervation Artery Notes
latissimusdorsi
vertebralspines from
30 to the
sacrum,posterior
third of the
iliac crest,
floor of theintertubercul
ar groove
extendsthe arm
and
rotatesthe arm
medially
thoracodorsal nerve
(0,8) from
the posteriorcord of the
brachial
plexus
thoracodorsal a.
theinserting
tendon
twists sothat fibers
originating
highest
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lower ! or* ribs,
sometimes
from theinferior
angle of thescapula
insertlowest
levator
scapulae
transverse
processes
of 1*vertebrae
medial
border of
the scapulafrom the
superior
angle to thespine
elevates
the
scapula
dorsal
scapular
nerve ();the upper
part of the
musclereceives
branches of
! *
dorsal
scapular a.
levator
scapulae is
named forits action
rhomboide
us ma'or
spines of
vertebrae33
medial
border ofthe scapula
inferior to
the spine of
the scapula
retracts,
elevatesand
rotates
the
scapulainferiorly
dorsal
scapularnerve ()
dorsal
scapular a.
named for
its shape
rhomboideus minor
inferior endof the
ligamentumnuchae,
spines ofvertebrae
0 and 31
medialborder of
the scapulaat the root of
the spine ofthe scapula
retracts,elevates
androtates
thescapula
inferiorly
dorsalscapular
nerve ()
dorsalscapular a
named forits shape
serratus
anterior
ribs 18 or
9
medial
border of
the scapulaon its costal
(deep)
surface
it draws
the
scapulaforward;
the
inferiorfibers
rotate the
scapulasuperiorl
y
long thoracic
nerve (from
ventral rami0)
lateral
thoracic a.
a lesion of
long
thoracicnerve will
cause
winging ofthe scapula
(i.e., the
medialborder of
the scapula
falls away
from the
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posteriorchest wall
and loo"s
li"e anangels
wing)
trape#ius medialthird of the
superior
nuchal line,external
occipital
protuberance,
ligamentum
nuchae,spinousprocesses
of
vertebrae031
lateral thirdof the
clavicle,
medial sideof the
acromion
and theupper crest
of the
scapularspine,tubercle of
the scapular
spine
elevatesand
depresses
thescapula
(dependi
ng onwhich
part of
themusclecontracts)
; rotates
thescapula
superiorl
y; retractsscapula
motor: spinalaccessory
(X),
proprioception: !*
transversecervical a.
named forits shape;
trape#ius is
an exampleof a muscle
that
migratesduring
developme
nt from itslevel oforigin
(cervical)
to its finalposition,
pulling its
nerve andartery
along
behind
&uscles of the Back Region - Listed Alphabetically
&uscle OriginInsertio
nAction
Innervatio
nArtery Notes
erector spinae iliac crest,
sacrum,
transverseand spinous
processes of
vertebraeand
supraspinal
ligament
angles of
the ribs,
transverse and
spinous
processes of
vertebrae
,posterior
extends
and
laterallybends
the
trun",nec"
and
head
segmentall
y
innervatedby dorsal
primary
rami ofspinal
nerves 1
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aspect ofthe s"ull
position andspinalis
medially; each
of thesecolumns has
multiplenamed parts
iliocostalis iliac crest
and sacrum
angles of
the ribs
extends
and
laterallybends
the
trun"and
nec"
dorsal
primary
rami ofspinal
nerves *
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andmastoid
process
nec"and
head
aa.,subcostal
aa.,
lumbar aa.
into thoracis,cervicis and
capitis
portions
multifidus sacrum,transverse
processes of!+
spinousprocesse
s *vertebral
levels
superiorto their
origin
extendand
laterallybend
trun"
andnec",
rotate to
opposite side
dorsalprimary
rami ofspinal
nerves 1
+
suppliedsegmentall
y by: deepcervical a.,
posterior
intercostalaa.,
subcostal
aa.,lumbar aa.
semispinalis,multifidus and
rotatores ma"eup the
transversospin
al musclegroup
obliuuscapitis inferior
spinousprocess of
the axis
transverse process
of atlas
rotatesthe
head to
thesame
side
suboccipital nerve
(=>? of
1)
occipital a. greateroccipital nerve
(=>? of )
passessuperiorly
around the
inferior
margin ofinferior
obliue
obliuus
capitis superior
transverse
process ofatlas
occipital
boneabove
inferiornuchal
line
extends
thehead,
rotatesthe
head to
thesame
side
suboccipita
l nerve(=>? of
1)
occipital a. the
suboccipitaltriangle is
formed byobliuus
capitis
superior andinferior and
rectus capitis
posteriorma'or
rectus capitisposterior ma'or spinousprocess of
axis
inferiornuchal
line
extendsthe
head,
rotate tosame
side
suboccipital nerve
(=>? of
1)
occipital a. none
rectus capitis posterior inferior extends suboccipita occipital a. rectus capitis
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posteriorminor
tubercle ofatlas
nuchalline
medially
thehead
l nerve(=>? of
1)
posteriorminor is
deeper and
inserts moremedial than
rectus capitisposteriorma'or
rotatores transverse
processes
long
rotatores: spines
vertebraeabove
origin;
shortrotatores: spines
1
vertebraeabove
origin
rotates
thevertebra
l
columnto the
opposit
e side
dorsal
primaryrami of
spinal
nerves 1+
supplied
segmentally by: deep
cervical a.,
posteriorintercostal
aa.,
subcostalaa.,lumbar aa.
semispinalis,
multifidus androtatores ma"e
up the
transversospinal muscle
group
semispinalis transverse
processes of
031
capitis:
bac" of
s"ullbetween
nuchal
lines;cervicis
thoracis:
spines */
vertebrae
aboveorigin
extends
the
trun"and
laterally
bendsthe
trun",
rotates
thetrun" to
the
opposite side
dorsal
primary
rami ofspinal
nerves 1
31
supplied
segmentall
y by: deepcervical a.,
posterior
intercostalaa.,
subcostal
aa.,
lumbar aa.
three parts are
named based
on theirinsertions:
capitis,
cervicis andthoracis;
semispinalis,
multifidus and
rotatores ma"eup the
transversospin
al musclegroup
serratusposterior
inferior
thoracolumbar fascia,
spines of
vertebrae
31131 and+1+
ribs 91,
lateral to
the
angles
pullsdown
lower
ribs
branchesof the
ventral
primary
rami ofspinal
nerves 39
31
lowestposterior
intercostal
a.,
subcostala., first
two
lumbar aa.
a respiratorymuscle, it
receives
ventral ramus
innervation;embryonically
related to the
intercostal
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muscles, notthe deep bac"
mm.
serratus
posteriorsuperior
ligamentum
nuchae,spines of
vertebrae 0and 313!
ribs 1*,
lateral tothe
angles
elevates
theupper
ribs
branches
of theventral
primaryrami of
spinal
nerves 313*
posterior
intercostalaa. 1*
a respiratory
muscle, itreceives
ventral ramusinnervation;
embryonically
related to theintercostal
muscles, not
the deep bac"mm.
spinalis spinousprocesses at
inferior
vertebrallevels
spinousprocesse
s at
superiorvertebral
levels
and base
of thes"ull
extendsand
laterally
bendstrun"
and
nec"
dorsalprimary
rami of
spinalnerves
+!
suppliedsegmentall
y by: deep
cervical a.,posterior
intercostal
aa.,
subcostalaa.,
lumbar aa.
most medialpart of the
erector spinae;
may besubdivided
into thoracis,
cervicis and
capitisportions
splenius ligamentum
nuchae andspines 0
3/
capitis:
mastoidprocess
superior
nuchal
linelaterally;
cervicis:
posteriortubercles
of 1
!vertebrae
extends
andlaterally
bendsnec"
and
head;rotates
head to
sameside
dorsal
primaryrami of
spinalnerves
/
supplied
segmentally by: deep
cervical a.,posterior
intercostal
aa.
splenius
meansbandage; it
gets its namefrom its broad,
flat shape
splenius capitis ligamentumnuchae and
spines of
03/
vertebrae
mastoidprocess
and
lateral
end of
extendsand
laterally
bends
the
dorsalprimary
rami of
spinal
nerves
suppliedsegmentall
y by: deep
cervical a.,
posterior
named for itsshape:
splenius
means
bandage and
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thesuperior
nuchal
line
nec"and
head,
rotateshead to
thesameside
/ intercostalaa.
capitis refersto the
insertion of
this portion ofthe muscle
splenius
cervicis
ligamentum
nuchae andspines of
03/
vertebrae
posterior
tuberclesof the
transvers
eprocesse
s of 1
!vertebrae
extends
andlaterally
bends
nec"and
head,
rotateshead tothe
same
side
dorsal
primaryrami of
spinal
nerves /
supplied
segmentally by: deep
cervical a.,
posteriorintercostal
aa.
named for its
shape:splenius
means
bandage andcervicis refers
to the
insertion ofthis portion ofthe muscle
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Nerves of the Back Region - Listed Alphabetically
Nerve Source Branches &otor Sensory Notes
accessory cranialroot:
medulla nucleus
ambiguus
; spinal
root:spinal
nucleus
of theupper
cervicalspinalcord
no namedbranches
2
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nerves
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nerve; location ofthe cell bodies of
somatic afferent
(sensory) neurons
dorsalscapular
n.
brachialplexus
(br. of ventral
primary
ramus)
no namedbranches
rhomboideusma'or and minor
mm.; levatorscapulae m.
none dorsal scapular n.passes through the
scalenus mediusm.
intercosta
l n.
ventral
primaryrami of
spinal
nerves31311
lateral
anteriorcutaneous
brs.
intercostal
muscles;abdominal wall
muscles (via 30
311); muscles ofthe forearm and
hand (via 31)
s"in of the
chest andabdomen
anterolaterall
y; s"in of themedial side of
the upper
limb (via 313)
intercostal
n.travels below theposterior
intercostal a. in
the costal groove
occipital,
greater
dorsal
primaryramus of
spinal
nerve (medial
br.)
no named
branches
posterior nec"
muscles
s"in of the
posteriorsurface of the
scalp
muscles
innervated by thisnerve develop
from epimeres in
the embryo
occipital,
lesser
ventral
primary
ramus ofspinal
nerve
no named
branches
none s"in behind
the ear
lesser occipital n.
arises from the
cervical plexus
occipitalis tertius
dorsalprimary
ramus of
spinal
nerve !(medial
br.)
no namedbranches
posterior nec"muscles
s"in of theposterior
surface of the
nec"
musclesinnervated by this
nerve develop
from epimeres in
the embryo
ramus,
dorsalprimary
first
branchoff of the
dorsal
numerous to the deep bac"
mm.; sympatheticinnervation to the
s"in
general sense
(touch,pressure,
pain, heat,
a mixed nerve
containing bothmotor and sensory
fibers
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side ofthe spinal
nerve
cold, etc.) tothe s"in of
the bac"
ramus,
ventralprimary
first
branchoff of the
ventralside of
the spinal
nerve
numerous to s"eletal mm. of
the nec", trun"and extremities;
sympatheticinnervation to the
s"in
general sense
(touch,pressure,
pain, heat,cold, etc.) to
the s"in of
the trun"(except the
bac") and
extremities;visceral pain
via the white
rami of thesympatheticnervous
system (31
+)
a mixed nerve
containing bothmotor and sensory
fibers
root,
dorsal
from the
dorsalhorn of
the spinal
cord tothe spinal
nerve
none none general sense
(touch,pressure,
pain, heat,
cold, etc.)
dorsal root is
entirely sensory infunction; it is
located dorsal to
the denticulateligament
root,ventral
from theventral
horn of
the spinalcord to
the spinal
nerve
none to s"eletal mm.;preganglionic
sympathetic (31
+)
none entirely motor infunction; located
ventral to the
denticulateligament; at all
spinal core levels
it contains 2
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spinal n. formed atthe point
where the
dorsaland
ventralrootletsmeet; it
ends
where the
dorsaland
ventral
primaryrami
diverge
dorsalprimary
ramus;
ventralprimary
ramus
to s"eletal mm.;some levels carry
preganglionic
sympathetic axons(31+)
general sense(touch,
pressure,
pain, heat,cold, etc.)
from theentire surfaceof the nec",
trun" and
extremities;
visceral pain(via the white
ramus
communicansand the
sympathetic
nervoussystem)
located at theintervertebral
foramen; there are
!1 pairs of spinalnerves 8
cervical, 1thoracic, lumbar, sacral, 1
coccygeal
ventral
primaryramus
first
branchoff of the
ventral
side ofthe spinal
nerve
numerous to s"eletal mm. of
the nec", trun"and extremities;
sympathetic
innervation to thes"in
general sense
(touch,pressure,
pain, heat,
cold, etc.) tothe s"in of
the trun"
(except the
bac") andextremities;
visceral pain
via the whiterami of the
sympathetic
nervoussystem (31
+)
a mixed nerve
containing bothmotor and sensory
fibers
ventral
root
from the
ventral
horn ofthe spinal
cord to
the spinalnerve
none to s"eletal mm.;
preganglionic
sympathetic (31+)
none entirely motor in
function; located
ventral to thedenticulate
ligament; at all
spinal core levelsit contains 2
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contains 2A@(preganglionic
sympathetic) for
blood vessels,sweat glands,
thoracic viscera,abdominal viscera,pelvic viscera
(opographical Anatoy of the Back - Listed
Alphabetically
Structure#Space Description#Boundaries Significance
external occipital a bump located in the midline on the the medial ends of the
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protuberance posterior surface of the occipital bone superior nuchal lines meetat the external occipital
protuberance; the
ligamentum nuchaeattaches here
lumbar triangle a triangle defined by the border of the
latissimus dorsi m. medially, the externalabdominal obliue m. laterally and the
iliac crest inferiorly; its floor is the
internal abdominal obliue m.
lumbar triangle may be
the site of an abdominalhernia; also "nown as:
triangle of >etit
natal cleft midline cleft between the buttoc"s natal cleft lies between the
gluteus maximus muscles
paravertebral line an imaginary line located lateral to the
midline on the posterior surface of the
body, parallel to the vertebral column
paravertebral line is used
as a descriptive landmar"
uadrangularspace
an area on the posterior surface of thebac" bounded by the teres minor m.
superiorly, the teres ma'or m. inferiorly,
the long head of the triceps brachii m.medially and the humerus laterally
the axillary n. and theposterior circumflex
humeral a. pass through
this space
triangle of
auscultation
a triangle located below the inferior angle
of the scapula bounded by the trape#iusm. medially, rhomboideus ma'or m.
superiorly and the latissimus dorsi m.
inferiorly; its floor is the posteriorthoracic wall
triangle of auscultation is
used to listen to(auscultate) the lungs
because the stethoscope
can be placed close to thethoracic wall at this
location
triangular interval the interval between the teres ma'or m.
superiorly, long head of the triceps brachii
m. medially and humerus laterally
the radial n. passes
through this interval to get
from the axilla to theposterior surface of the
humerus
triangular space the space bounded by the teres minor m.
superiorly, the teres ma'or m. inferiorlyand the long head of the triceps brachii m.
laterally
the circumflex scapular
vessels are located in thisspace as they pass from
the axilla to the dorsum ofthe scapula
vertebraprominens
the 0 vertebra, so named because itsspine is easily seen and palpated
vertebra prominens is aneasily palpable landmar"
which indicates the level
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of transition from cervicalto thoracic vertebra
vertebral furrow midline furrow down the bac" surface landmar" thatindicates the location of
the vertebral spines; theerector spinae muscle
masses lie on either sideof it