Back Flashcards
Vertebral column movements are limited by:
IV discs, articular facets, back muscles, ligamenta flava, posterior longitudinal ligament, thoracic cage attachments
vertebral column movements
flexion, extension, lateral flexion, rotation
ventral roots:
efferent (motor)
dorsal roots:
afferent (sensory)
cutaneous innervation of the back
dorsal primary rami
deep back muscles are innervated by:
dorsal primary rami
superficial extrinsic back muscles are innervated by:
ventral primary rami of cervical nerves (because the superficial back muscles act on upper limbs) (exception: trapezius innervated by accessory nerve CN XI)
skeletal muscles (other than deep back) are innervated by:
ventral primary rami
location of cell body in efferent nerves
CNS
location of cell body in afferent nerves
dorsal root ganglion
nerve leaving intervertebral foramen is:
mixed spinal nerve
white rami exist at what levels?
T1-L2/L3
function of superficial extrinsic back muscles
movement of upper limb
trapezius innervation
accessory nerve (CN XI)
superficial extrinsic back muscles:
trapezius, latissimus dorsi, levator scapulae, rhomboid major, rhomboid minor
intermediate extrinsic back muscles:
serratus posterior superior, serratus posterior inferior
function of intermediate extrinsic back muscles
superficial respiratory, proprioceptive
latissimus dorsi inntervation
Thoracodorsal N. (C6-C8)
levator scapulae innervation
dorsal scapular (C5), cervical nerves (C3-C4)
erector spinae origin
posterior sacrum, iliac crest, sacrospinous ligament, supraspinous ligament, spinous processes of lower lumbar and sacral vertebrae
iliocostalis insertion
angles of lower ribs, cervical transverse processes
longissiumus insertion
between tubercles and angles of ribs, transverse processes of thoracic and cervical vertebrae, mastoid process
spinalis insertion
spinous processes of upper thoracic and midcervical vertebrae
erector spinae innervation
dorsal rami of each region
erector spinae actions
extends and laterally bends vertebral column and head
cervical portions of erector spinae blood supply
occipital, deep cervical, and vertebral arteries
thoracic portions of erector spinae blood supply
dorsal branches of posterior intercostal, subcostal, and lumbar arteries
sacral portions of erector spinae blood supply
dorsal branches of lateral sacral arteries
interspinales origin
spinous processes
interspinales insertion
adjacent spinous process
interspinalis innervation
dorsal rami of spinal nerves
interspinales action
aids in extension of vertebral column
interspinales blood supply (cervical portions)
occipital, deep cervical, and vertebral arteries
interspinales blood supply (thoracic portions)
dorsal branches of posterior intercostal arteries
interspinales blood supply (lumbar portions)
dorsal branches of lumbar arteries
intertransversarii origin/insertion
extend between adjacent transverse processes of vertebrae
intertransversarii innervation
dorsal and ventral rami of spinal nerves
intertransversarii actions
assist in lateral flexion of vertebral column
intertransversarii blood supply (cervical portions)
occipital, deep cervical, and vertebral arteries
intertransversarii blood supply (thoracic portions)
dorsal branches of posterior intercostal, subcostal, and lumbar arteries
intertransversarii blood supply (lumbar portions)
dorsal branches of lateral lumbar arteries
latissimus dorsi origin
spinous processes T7-L5, thoracolumbar fascia, iliac crest, and last 3 ribs
latissimus dorsi insertion
humerus (intertubercular sulcus)
latissimus dorsi action
“swimmer’s muscle” - extension, adduction, and medial rotation of humerus
latissimus dorsi blood supply
thoracodorsal artery
levator scapulae origin
posterior tubercles of transverse processes of C1-C4
levator scapulae insertion
medial border of scapular from superior angle to spine
levator scapulae innervation
ventral rami of C3-C4 and dorsal scapular nerve
levator scapulae action
elevate scapula medially, inferiorly rotates glenoid cavity
levator scapulae blood supply
dorsal scapular artery, transverse cervical artery, ascending cervical artery
multifidus origin
sacrum, ilium, transverse processes of T1-T12, and articular processes of C4-C7
multifidus insertion
spinous processes of vertebrae above, spanning 2-4 segments
multifidus innervation
dorsal rami of each region
multifidus action
stabilizes spine
multifidus blood supply (cervical portion)
occipital, deep cervical, and vertebral arteries
multifidus blood supply (thoracic portion)
dorsal branches of posterior, intercostal, subcostal, and lumbar arteries
multifidus blood supply (sacral portion)
dorsal branches of lateral sacral arteries
obliquus capitis inferior origin
spine of axis
obliquus capitis inferior insertion
transverse process of atlas
obliquus capitis inferior innervation
suboccipital nerve
obliquus capitis inferior action
rotates atlas to turn face to same side
obliquus capitis inferior blood supply
vertebral artery, descending branch of occipital artery
obliquus capitis superior origin
transverse process of atlas
obliquus capitis superior insertion
occipital bone
obliquus capitis superior innervation
suboccipital nerve
obliquus capitis superior action
extends and bends head laterally
obliquus capitis superior blood supply
vertebral artery, descending branch of occipital artery
rectus capitis posterior major origin
spine of axis
rectus capitis posterior major insertion
inferior nuchal line
rectus capitis posterior major innervation
suboccipital nerve
rectus capitis posterior major action
extends and rotates head to same side
rectus capitis posterior major blood supply
vertebral artery, descending branch of occipital artery
rectus capitis posterior minor origin
tubercle of posterior arch of atlas
rectus capitis posterior minor insertion
median inferior nuchal line
rectus capitis posterior minor inervation
suboccipital nerve
rectus capitis posterior minor action
extends head
rectus capitis posterior minor blood supply
vertebral artery, descending branch of occipital artery
rhomboid major origin
spinous processes of T2-T5
rhomboid major insertion
medial border of scapula below base of spine of scapula
rhomboid major innervation
dorsal scapular nerve (C4, C5)
rhomboid major action
fixes scapula to thoracic wall and retracts and rotates it to depress glenoid cavity
rhomboid major blood supply
dorsal scapular artery
rhomboid minor origin
ligamentum nuchae, spines of C7 and T1
rhomboid minor insertion
medial border of scapula at spine of scapula
rhomboid minor innervation
dorsal scapular nerve (C4, C5)
rhomboid minor action
fixes scapula to thoracic wall and retracts and rotates it to depress glenoid cavity
rhomboid minor blood supply
dorsal scapular artery
rotatores origin
transverse processes of cervical, thoracic, and lumbar regions
rotatores insertion
lamina and transverse process of spine above, spanning 1-2 segments
rotatores innervation
dorsal rami of spinal nerves
rotatores action
stabilize, extend, rotate spine
rotatores blood supply
dorsal branches of segmental arteries
semispinalis origin
transverse processes of C4-T12
semispinalis insertion
spinous processes of cervical and thoracic regions
semispinalis innervation
dorsal rami of spinal nerves
semispinalis action
extend head, neck, and thorax and rotate them to the opposite side
semispinalis blood supply (cervical portions)
occipital, deep cervical, and vertebral arteries
semispinalis blood supply (thoracic portions)
dorsal branches of posterior intercostal arteries
serratus posterior inferior origin
spinous processes of T11-L2
serratus posterior inferior insertion
inferior aspect of ribs 9-12
serratus posterior inferior innervation
ventral rami of lower thoracic nerves
serratus posterior inferior action
depresses ribs
serratus posterior inferior blood supply
posterior intercostal arteries
serratus posterior superior origin
ligamentum nuchae, spinous processes of C7-T3
serratus posterior superior insertion
superior aspect of ribs 2-4
serratus posterior superior innervation
ventral rami of upper thoracic nerves
serratus posterior superior action
elevates ribs
serratus posterior superior blood supply
posterior intercostal arteries
splenius capitis origin
nuchal ligament, spinous processes of C7-T3
splenius capitis insertion
mastoid process of temporal bone, lateral third of superior nuchal line
splenius capitis innervation
dorsal rami of middle cervical nerves
splenius capitis action
bilaterally: extend head. unilaterally: laterally bends (flexes) and rotates neck toward same side
splenius capitis blood supply
descending branch of occipital artery, deep cervical artery
splenius cervicis origin
spinous process of T3-T6
splenius cervicis insertion
transverse processes C1-C3
splenius cervicis innervation
dorsal rami of lower cervical nerves
splenius cervicis action
bilaterally: extend neck. unilateally: laterally bends (flexes) and rotates neck toward same side
splenius cervicis blood supply
descending branch of occipital artery, deep cervical artery
trapezius origin
superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes of C7-T12
trapezius insertion
lateral third of clavicle, acromion, spine of scapula
trapezius action
elevates, retracts, and rotates scapula; lower fibers depress scapula
trapezius blood supply
transverse cervical artery, dorsal perforating branches of posterior intercostal arteries
C5 dermatome
clavicles
C5, C6 dermatomes
lateral sides of upper limbs
C8, T1 dermatomes
medial sides of upper limbs
C6 dermatome
digit I (thumb)
C6, C7, C8 dermatomes
hand
C8 dermatome
digits IV and V (ring and little fingers)
T4 dermatome
level of nipples
T10 dermatome
level of umbilicus
L1 dermatome
inguinal region
L1, L2, L3, L4 dermatomes
anterior and inner surfaces of lower limbs
L4, L5, S1 dermatomes
foot
L4 dermatome
medial side digit I (great toe)
L5, S1, S2 dermatomes
lateral and posterior surfaces of lower limbs
S1 dermatome
lateral margin of foot and digit V (little toe)
S2, S3, S4 dermatomes
perineum
deep back muscles action
maintain posture, control movement of vertebral column
cervical movements
flexion, extension, rotation, lateral flexion
chief extensors of vertebral column
erector spinae muscles (iliocostalis, longissimus, spinals)
transversospinalis muscles:
semispinalis (capitis, cervicis, thoracis), multifidus, rotatores
levatores costarum origin
tips of transverse processes of C7-T11
levatores costarum insertion
inferolaterally to rib between tubercle and angle
levatores costarum innervation
posterior rami of C8-T11 spinal nerves
levatores costarum action
elevate ribs, assist respiration, aid lateral flexion of vertebral column
intrinsic deep muscles:
interspinalis, intertransversarii, levatores costarum
annulus fibrosis
outer layer of intervertebral disc
nucleus pulposus
hydrophilic, jelly-like inner layer of intervertebral disc
primary curvatures of spine
thoracic and sacral kyphoses
secondary curvatures of spine
cervical and lumbar lordoses
facet joints innervation
articular branches from medial branches of posterior rami spinal nerves
facet joints function
limit movement of vertebral column
ligaments that limit spinal extension
anterior longitudinal ligament
ligaments that limit spinal flexion
posterior longitudinal ligament, ligamentum flavum, supraspinous and interspinous ligaments
ligaments that limit lateral bending
intertransverse ligaments
median atlantoaxial joint function
“no” movement
lateral atlanto-occiptal joints
“yes” movement
most common cause of back pain
strain of erector spinae muscles
suboccipital triangle borders
rectus capitis posterior major (superomedially), obliquus capitis superior (superolaterally), obliquus capitis inferior (inferolaterally), posterior atlanto-occipital membrane and posterior arch of C1 (floor), semispinalis capitis (roof)
suboccipital triangle contents
suboccipital nerve (C1), vertebral artery
suboccipital triangle muscles
rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, obliquus capitis inferior
ganglion
collection of nerve cell bodies
demyelinating diseases
multiple sclerosis in CNS, guillain-barre syndrome in PNS
gray matter is composed of:
nerve cell bodies
white matter is composed of:
axons
meninges:
dura mater (outer layer), subarachnoid mater, pia mater (inner layer)
functional organization of peripheral nervous system
somatic (voluntary) and autonomic (involuntary/visceral)
somatic sensory
connective tissue; sensations (pain, temperature, pressure), muscle spindles (proprioception), golgi tendon organs, pleura, peritoneum, skin, joints
visceral sensory
sensations (poorly localized; pain may seem like hunger or nausea)
somatic motor
exclusive to skeletal muscle
visceral motor
heart, smooth muscles, glands
visceral motor neuron
2 neurons between CNS and motor tissue; preganglionic neuron cell body in CNS, postganglionic neuron cell body in autonomic ganglion
somatic motor neuron
1 neuron between CNS and motor tissue; cell body in CNS
dorsal root ganglion
contains cell body of sensory neuron
ventral horn
contains cell bodies of motor neurons
sympathetic division
thoracolumbar (T1-L2/3); catabolic (fight or flight) effects on autonomic nervous system
parasympathetic division
craniosacral (CN III, CN VII, CN IX, CN X, S2, S3, S4); anabolic (rest and digest) effects on autonomic nervous system
dorsal scapular nerve
C5
suboccipital nerve
C1
greater occipital nerve
C2
thoracodorsal nerve
C6-C8
neurotransmitter used in sympathetic division
norepinephrine (except in sweat glands - acetylcholine)
neurotransmitter used in parasympathetic division
acetylcholine
location of presynaptic neurons of sympathetic division
intermediolateral (IML) cell columns
interomediolateral cell columns (IMLs)
lateral horns; part of gray matter from T1-L2/3; location of presynaptic neurons of sympathetic division
paravertebral ganglia
form right and left sympathetic trunks on sides of vertebral column
prevertebral ganglia
located in the plexuses that surround the origins of main branches of abdominal aorta
cervical enlargement
C4-T1; forms brachial plexus, innervates upper limbs
lumbosacral (lumbar) enlargement
L1-S3; forms lumbar and sacral plexuses, innervates lower limbs
pairs of spinal nerves
31 (8C, 12T, 5L, 5S, 1Co)
posterior rami supply:
zygapophysial joints, deep muscles of back, and overlying skin
anterior rami supply:
muscles, joints, and skin of limbs, and remainder of trunk
filum terminale internum consists mainly of
pia mater
filum terminale externum consists of
dura mater
filum terminale externum passes through _________ to ultimately attach to coccyx posteriorly
sacral hiatus
characteristics of typical thoracic vertebrae
round vertebral foramen, demifacets/costal facets, heart-shaped v. body
characteristics of typical cervical vertebrae
transverse foramen, bifid spinous process, large v. foramen, uncinate process
characteristics of typical lumbar vertebrae
large v. body, kidney-shaped body, transverse processes protrude more laterally, spinous process is hatchet-shaped
characteristics of atlas (C1)
no spinous process, no body, anterior and posterior arches, posterior tubercle, lateral masses, no IV disc
characteristics of axis (C2)
strongest cervical v., has dens
functions of ligamentum flavum
resist separation of lamina, limit abrupt flexion (prevents injury to IV disc), assist with straightening column after flexing
uncovertebral joints (clefts of Luschka)
located between uncinate processes of C3-C6. synovial joint-like. frequent site of bone spur formation
scotty dog fracture
fracture at pars interarticularis (part of lamina)
hangman’s fracture
fracture of both pedicles or pars interarticularis of the axis
spondylolysis
a defect or fracture of the pars interarticularis of the vertebral arch; most common cause of spondylolisthesis
spondylolisthesis
the forward displacement of a vertebra (typically L5), most commonly occurring after a fracture
Jefferson or Burst fracture
C1 fx; vertical forces to head lead to fx of anterior and/or posterior arch; not necessarily resulting in spinal cord inj. If transverse lig. ruptures, spinal cord inj. more likely
rupture of transverse ligament of atlas
leads to atlanto-axial subluxation (dens is free)
lumbar cistern
L2-S2; contains CSF and cauda equina
arteries supplying spinal cord are branches of:
vertebral a., ascending cervical a., deep cervical a., intercostal a., lumbar and lateral sacral a.
arterial supply of neck region
vertebral and ascending cervical a.
arterial supply of thorax region
posterior intercostal a.
arterial supply of abdominal region
subcostal and lumbar a.
arterial supply of pelvic region
iliolumbar and lateral and medial sacral a.
internal vertebral venous plexus (IVVP)
AKA epidural plexus. inside vertebral canal. drains into segmental vein via intervertebral vein
external vertebral venous plexus
outside vertebral canal: communicates with internal vertebral venous plexus via intervertenral vein and basivertebral vein
spina bifida occulta
laminae of L5 and/or S1 fail to develop normally and fuse
degenerative disc disease (DDD)
structure and chemistry of IV disc changes over time; loss of water content and proteoglycan; making disc less resilient to stress and strain
osteophytes (bone spurs)
bony overgrowths caused by hypertrophy of v. bodies adjacent to a degenerating disc.
central spinal stenosis
narrowing of the central part of the spinal canal
foraminal spinal stenosis
narrowing of the foramen, resulting in pressure on the exiting nerve root
far lateral recess spinal stenosis
narrowing of the lateral part of the spinal canal
myelopathy
spinal cord compression
cauda equina syndrome
caused by central disc herniation. damage to the cauda equina causes loss of function
