Superficial and Deep Back Flashcards
What are the 3 groups of the muscles of the back? What is the function of each group?
- superficial - anchor upper limb to the axial skeleton
- intermediate - assist in respiration
- deep - maintain posture; act on vertebral column (raise and lower spine)
What is the innervation of the superficial back muscles?
ventral rami (due to embryological migration from ventrum)
What is the innervation of the intermediate back muscles?
ventral rami (due to embryological migration from ventrum)
What is the innervation of the deep back muscles?
dorsal rami (due to original dorsal embryological location)
To what group of back muscles does the trapezius belong?
superficial
To what group of back muscles does the latissimus dorsi muscle belong?
superficial
To what group of back muscles does the semispinalis capitis muscle belong?
deep
To what group of back muscles does the splenius capitis muscle belong?
deep
To what group of back muscles does the splenius cervicis muscle belong?
deep
To what group of back muscles does the levator scapulae muscle belong?
superficial
To what group of back muscles does the rhomboid minor muscle belong?
superficial
To what group of back muscles does the seratus posterior superior muscle belong?
intermediate
To what group of back muscles does the rhomboid major muscle belong?
superficial
To what group of back muscles does the serratus posterior inferior muscle belong?
intermediate
To what group of back muscles does the erector spinae muscles belong?
deep
What are the three erector spinae muscles?
- iliocostalis
- longissiumus
- spinalis
How do deep back muscles receive their innervation?
segmentally (at each spinal level in each region)
If an injury occurred in which 2 dorsal rami were lost, how would it affect the patient?
it wouldn’t; there is significant overlap between the dorsal rami nerves so there would be no clinical symptoms
True or false: Dorsal rami nerves are ipsilateral (do not cross at the midline).
true
Why is it helpful that the dorsal rami nerves are ipsilateral?
the midline represents a useful internervous plane for performing surgical procedures on the spine
What is the origin and insertion of the trapezius muscle?
- origin - superior nuchal line, nuchal ligament, C7-T12 spinous processes
- insertion - lateral clavicle, acromion, and spine of scapula
What is the action of the trapezius?
elevates, depresses, and retracts scapula
What is the vascular and nerve supply to the trapezius?
accessory nerve (CN XI) and transverse cervical vessels (and ventral rami of C3-C4 for proprioception)
What is the course of the accessory nerve to the trapezius muscle?
runs deep to the muscle posteroinferiorly from the jugular foramen
What is the course of the ventral rami of C3-C4 to the trapezius muscle?
runs deep to the muscle posteriorly from intervertebral foramen
What is the course of the transverse cervical artery and vein to the trapezius muscle?
runs deep to the muscle posterolaterally from thyrocervical trunk
What nerves make up the subtrapezial plexus? What is the function of each nerve?
- CN XI - motor to trapezius and SCM
- C3-C4 ventral rami - proprioception
What is proprioception?
ability to sense position, location, orientation, and movement of the body and/or parts of the body
What is the origin and insertion of the latissimus dorsi muscle?
- origin - T7-T12 spinous processes, TL fascia, and crest of the ilium
- insertion - intertubercular sulcus (bicipital groove) of humerus
What is the action of the latissimus dorsi muscle?
adducts, extends, and medially rotates humerus
What is the nerve and vascular supply of the latissimus dorsi muscle?
thoracodorsal nerve and vessels and intercostal vessels
What is the origin and insertion of the rhomboid minor and major muscles?
- origin - C7-T5 spinous processes
- insertion - medial border of scapula from spine to inferior angle
What is the action of the rhomboid muscles?
retract scapula
What is the nerve and vascular supply of the rhomboid muscles?
dorsal scapular nerves and vessels
What is the origin and insertion of the levator scapulae muscle?
- origin - transverse processes of the first 3-4 vertebrae
- insertion - upper medial border of the scapula
What is the action of the levator scapulae muscle?
elevates scapula
What is the nerve and vascular supply of the levator scapule muscle?
dorsal scapular nerves and vessels
What is the origin and insertion of the serratus anterior muscle?
- origin - lateral surface of first 8 ribs
- insertion - anterior surface of medial border of scapula
What is the action of the serratus anterior muscle?
protracts scapula and holds it to the body wall
What is the nerve and vascular supply of the serratus anterior muscle?
long thoracic nerve and lateral thoracic vessels
What are the boundaries of the triangle of auscultation?
- superior - trapezius muscle
- inferior - latissimus dorsi muscle
- lateral - rhomboid major muscle
- floor (deep) - 6th intercostal space (between 6th and 7th ribs)
What is the clinical significance of the triangle of auscultation?
allows for listening to the organs of thorax (via stethoscope) which has diagnostic importance
When is the triangle of auscultation accentuated?
when scapula is protracted
What are the boundaries of the lumbar triangle?
- medial - latissimus dorsi muscle
- lateral - external oblique muscle
- inferior - iliac crest
- floor (deep) - internal oblique muscle
What is the clinical significance of the lumbar triangle?
can become a site of lumar hernia
What is the origin and insertion of the serratus posterior superior muscle?
- origin - C7-T3 spinous processes
- insertion - superior border of ribs 2 through 4 (5)
What is the action of the serratus posterior superior muscle?
elevates upper ribs
What is the nerve and vascular supply of the serratus posterior superior muscle?
first 4 intercostal nerves and vessels
What is the origin and insertion of the serratus posterior inferior muscle?
- origin - T11-L2 spinous processes
- insertion - inferior border of ribs 8 (or 9) through 12
What is the action of the serratus posterior inferior muscle?
depresses lower ribs
What is the nerve and vascular supply of the serratus posterior inferior muscle?
last 4 intercostal nerves and vessels
What portion(s) of the back (cervical, thoracic, or lumbar) does the erector spinae muscles cover?
lumbar and thoracic
What portion(s) of the back (cervical, thoracic, or lumbar) does the splenius capitus and cervicis cover?
cervical
What portion(s) of the back (cervical, thoracic, or lumbar) does the semispinalis capitis and cervicis cover?
cervical
What portion(s) of the back (cervical, thoracic, or lumbar) does the multifidus cover?
lumbar
What portion(s) of the back (cervical, thoracic, or lumbar) does the rotatores cover?
thoracic
What is the origin and insertion of the erector spinae muscle?
- origin - posterior sacrum, ilium, and spinous processes
- insertion - spinous processes, transverse processes, and ribs
What is the action of the erector spinae muscles?
erect spine (postural muscles)
What is the nerve and vascular supply of the erector spinae muscles?
dorsal rami of spinal nerves and lumbar and intercostal vessels
What is the origin and insertion of the splenius capitis and cervicis muscles?
- origin (both) - nuchal ligament and upper spinous processes
- insertion (capitis) - occipital bone and mastoid process
- insertion (cervicis) - upper cervical transverse processes
What is the action of the splenius capitis and cervicis muscles?
extend and laterally rotate the head and neck
What is the nerve and vascular supply of the splenius capitis and cervicis muscles?
dorsal rami of spinal nerves and deep cervical vessels
What is the origin and insertion of the semispinalis capitis and cervicis muscles?
- origin (both) - upper thoracic transverse processes
- insertion (capitis) - occipital bone between nuchal lines
- insertion (cervicis) - upper cervical spines
What is the action of the semispinalis capitis and cervicis?
extend the head and neck
What is the nerve and vascular supply of the semispinalis capitis and cervicis?
dorsal rami of spinal nerves and deep cervical vessels
What is the origin and insertion of the multifidus muscle?
- origin - sacrum and lower transverse processes
- insertion - spinous processes (span 2-4 vertebrae)
What is the action of the multifidus muscle?
laterally flexes and rotates spine
What is the nerve and vascular supply of the multifidus muscle?
dorsal rami of spinal nerves and lumbar vessels
What is the origin and insertion of the rotatores muscle?
- origin - transverse processes
- insertion - spinous processes (span 1-2 vertebrae)
What is the action of the rotatores muscle?
rotate spine
What is the nerve and vascular supply of the rotatores muscle?
dorsal rami of spinal nerves and intercostal vessels
What are the 3 minor deep muscles of the back?
- interspinalis
- intertransversarius
- levator costarum
Where is the interspinalis muscle located? What is its function?
- between spinous processes
- minor extensors of spine
Where is the intertransversarius muscle located? What is its function?
- between transverse processes
- minor lateral flexors of spine
Where is the levator costarum muscle located? What is its function?
- from transverse process to ribs
- minor elevators of ribs