Deep muscles of the back Flashcards
another name for EOP
Inion
the landmark of the nuchal ligament is…
the nuchal groove
hyoid bone is located at the level of
C3
Thyroid cartilage is located at the level of…
C4-C5
the first cricoid ring is located at the level of…
C6
The level of the iliac crests is located at level…
L4 (supracristal plane)
the dimples in the back indicate…
the posterior superior iliac crests
Bony structures of the scapula
acromion coracoid process glenoid cavity neck angles and borders supra and infraglenoid tubercles suprascapular notch subscapular fossa spine supraspinous fossa infraspinous fossa
Bony structures of humerus
head anatomical neck surgical neck (more important for Fx) greater tubercle lesser tubercle intertubercular sulcus deltoid tuberosity
the deep muscle layers are layers…
4-6
A little about the spinal accessory nerve
It stems from CN X (vagus). the vagus rami goes ventrally and there is also a dorsal rami that splits off into the cranial root and the spinal accessory nerve (XI)
the spinal accessory nerve innervates which two muscles?
Trapezius and sternocleidomastoid–if the nerve is damaged you would see downward and lateral displacement of the scapula.
the dorsal scapular nerve innervates which two muscles?
the rhomboids and the levator scapulae (so it elevates, rotates, retracts and holds the scapula to the wall). if it is damaged you will have scapular winging.
Intrinsic muscles maintain…
posture
intrinsic muscles are innervated by the ____ rami
dorsal primary rami of the spinal nerves
there are four groups of intrinsic back muscles
spinotransversales, erector spinae, transversospinalis, intersegmental muscles-span one vertebra to adjacent vertebra (ie. interspinalis, levator costae, intertransversarii)
the extrinsic back muscles are innervated by the ___rami
ventral primary rami of spinal nerves
the spinotransversales muscles are the…
splenius capitis and cervicis (make up the one muscle called the splenius)
splenius capitis (O, I, N, A)
O: lower half of nuchal ligament, spinous processes of C7-T3 (like the serratus posterior superior)
I: transverse prcoesses of C1-C3 (so should be deep to levator scapulae)
N: dorsal primary rami
A: extends the head and neck, cervical rotation to same side, cervical lateral flexion
the erector spinae group
spinalis, logissimus, iliocostalis
erector spinae O I N A
O: sacrum, iliac crest
I: spinous processes (spinalis)
transverse processes and skull (longissimus)
ribs (iliocostalis)
N: dorsal rami of spinal nerves
A: extend (erect) the spine, bend laterally if contract one side
the 3 parts of the spinalis
thoracis, cervicis, and capitis
the 3 parts of the longissimus
thoracis, cervicis, capitis
the 3 parts of the iliocostalis
lumborum, thoracis, cervicis
the transversospinalis group
semispinalis, multifidus, rotatores
transversospinalis OINA
O&I: between spinous processes and transverse processes and skull (semispinalis capitis)
N: dorsal rami
A: stabilize the vertebral column if they all contract. or rotate or lateral bending of vertebrae if only one segment contracts
other deep muscles
levator costarum, intertransversarii, interspinales (mostly function as postural and proprioceptive transducers)
suboccipital triangle boundaries
rectus capitis posterior major, obliquus capitis superior and obliquua capitis inferior. (contents: vertebral artery and C1)
rectus capitis posterior major and oblique capitis inferior attach to…
the spine of the axis
rectus capitis posterior minor attaches at…
posterior tubercle of atlas
obliquus capitis superior and inferior attach at…
transverse process of atlas
more about the lesser occipital nerve
Arises from cervical plexus, conveying fibers from ventral primary rami of second and third cervical nerves; supplies skin of posterior surface of auricle and adjacent portion of the scalp posterior to auricle.
