Back Flashcards
What are the superficial extrinsic back muscles?
1) . trapezius
2) . latissimus dorsi
3) . rhomboids
4) . levator scapulae
What are the intermediate extrinsic back muscles?
S/I serratus posterior
where is the serratus posterior superior located?
deep to the rhomboids
where is the serratus posterior inferior located?
deep to latissimus dorsi
what do the intermediate extrinsic back muscles do?
rib cage proprioception (innervated by intercostal nerves)
what is the general action of the intrinsic (deep) back muscles?
maintain posture (balance) and extend, ab-/adduct, and rotate the vertebral column
which layer of the intrinsic back muscles is longer?
superficial and intermediate layers (span 5-8 segments)
intrinsic back muscles (superficial layer)
Splenius (capitis and cervicis)
prox attachment of splenius capitis
nuchal ligament
distal attachment of splenius capitis
mastoid process
prox attachment of splenius cervicis
lower C and upper T spinous processes
distal attachment of splenius cervicis
superior cervical transverse process
innervation of splenius capitis and splenius cervicis
dorsal rami
intrinsic back muscles (intermediate layer)
Erector spinae muscles
erector spinae muscles
1) . Iliocostalis
2) . Longissimus
3) . Spinalis
all erector spinae have how many parts?
3
what are the 3 parts of the Iliocostalis?
lumborum, thoracis, cervicis
what are the 3 parts of the longissimus?
thoracis, cervicis, and capitis
what are the 3 parts of the spinalis?
thoracis, cervicis, capitis
origin of Iliocostalis
pelvis and lumbar spinous processes
insertion of Iliocostalis
ribs & lower cervical transverse processes
origin of longissimus
vertebral column spinous processes
intrinsic back muscles (deep layer)
1) . semispinalis
2) . multifidus
3) . Rotatores
intrinsic back muscles (deep layer) location?
“gutter” between spinous and transverse processes
what is the intrinsic deep layer also called?
Transversospinalis muscle group
what are the 3 parts of the semispinalis?
thoracis, cervicis, and capitis
origin of semispinalis
lower cervical & thoracic transverse processes
insertion of semispinalis
thoracic, cervical spinous processes & occipital/nuchal lines 4-6 segments above origin
3 parts of the multifidus
lumborum, thoracis, cervicis
where is multifidus largest?
lumborum lordotic curve
origin of multifidus
pelvis, lumber, thoracic, lower cervical transverse processes
insertion of multifidus
spinous process 2-4 segments above origin
where are the rotatores mostly located?
thoracic region
rotatores origin
transverse process of thoracic vert
rotatores insertion
spinous process of lamina 1 (brevis) or 2 (longus) segements above origin
muscles in the minor deep layer
1) . Interspinales
2) . Intertransversari cervicis; lumborum
3) . Levatores costarum, thoracicis
unique feature of minor deep layer
cross 1 intervertebral joint
what is the function of the minor deep layer?
stabilize vertebral column (posture)
Interspinales attachments
spinous processes to spinous process
Intertransversari attachments
transverse process to transverse process
Levatores costarum/thoracicis attachment
thoracic transverse process -> adjacent rib
what is the function of the Levatores costarum:thoracicis?
functions in respiration to assist in lifting the rib cage for inspiration
Suboccipital muscles
1) . rectus capitis posterior major
2) . rectus capitis posterior minor
3) . obliquus capitis inferior
4) . Obliquus capitis superior
innervation of all suboccipital muscles
suboccipital nerve (dorsal rami C1)
Rectus capitis post major attachments
C2 spinous p -> occipital bone/lateral nuchal line
Rectus capitis post min attachments
C1/post tubercle of posterior arch -> occipital bone/medial nuchal line
Obliquus capitis inf attachments
C2/spinous process -> C1 transverse process
Obliquus capitis superior attachments
C1/transverse process -> occipital bone/lateral nuchal lines
Superior/medial boundary of the suboccipital triangle
rectus capitis post major
Inferolateral boundary of the suboccipital triangle
obliquus capitis inf
superolateral boundary of the suboccipital triangle
obliquus capitis superior
Floor of the suboccipital triangle
post altanto-occipital membrane
Roof of the suboccipital triangle
semispinalis capitis
Suboccipital triangle contents
vertebral artery/vein and suboccipital nerve
Nerves around the suboccipital triangle
Cutaneous nerves (greater occipital; lesser occipital; great auricular) dorsal rami of C3-C7
layers of protective covering in the spinal cord
1) . epidural space
2) . dura mater
3) . arachnoid mater
4) . pia mater
what is the epidural space?
lipid filled space between wall of vertebral canal and dura mater
what is the dura mater layer?
CT membrane covering of spinal cord. Runs from foramen magnum to sacral hiatus. Also called dural sac.
What is the dural sac?
continuous with epineurium, covering dorsal/ventral roots & spinal nerves; and dural covering of the brain
what is between the dura mater and arachnoid mater?
subdural space/dura-arachnoid interface
what is in the subdural space?
interstitial fluid
what is the arachnoid mater?
CT membrane (thinner than dura) covering the spinal cord, roots, and dorsal root ganglion
what is between the arachnoid mater and pia mater?
subarachnoid space
what is in the subarachnoid space?
CSF and CT traceculae connecting arachnoid and pia maters
what is the pia mater?
thin, translucent, covering adhering to spinal cord
2 components of pia mater in spine
1) . denticulate ligaments
2) . filum terminal
what are the denticulate ligaments?
lateral sheets of pia running from sacrum to foramen magnum, attach laterally to the arachnoid and help hold the spinal cord in place
what is the filum terminal?
an inferior continuation of pia connecting the conus medullaris to the coccyx
length of spinal cord
2/3 of vert column. Runs from foramen magnum thru vert canal to level of L1/2 ending in the conus medullaris
components of a spinal cord segment
dorsal root/dorsal root ganglion and ventral root. These exit the spinal cord then fuse to form proximal spinal nerves
where do spinal nerves exit the vertebral column?
intervertebral foramena
after spinal nerves exit how do they divide further?
distally in to ventral and dorsal rami
how many spinal cord segments are there?
31 (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal)
how many total spinal nerves?
62 (all 31 are paired R/L)
what is the cauda equina?
structure in lumbosacral vertebral canal consisting of roots from lumbosacral spinal cord segments
what is the filum terminal?
continuation of pia matter attaching the conus meduallaris to the coccyx
what are the main arteries supplying the spinal cord?
1) . vertebral, subclavian arteries
2) . intercostal arteries
3) . lumbar arteries
4) . lateral sacral arteries
segmental branches from the main arteries form what?
longitudinal arteries that run anterior and posterior
how many posterior spinal arteries are there?
2