Gross Anatomy

  1. Extrinsic muscles of the back
    associated with the ribs or upper limbs superficially, not true back muscles
  2. Intrinsic back muscles
    deep and involved with axial skeleton
  3. Intrinsic back muscle properties
    • Action-move spine
    • Location-hollow space b/w vertebral spinous processes and angles of ribs
    • They are contained in a tube of fascia which extends whole vert column
    • In the neck- called prevertebral fascia
    • Inferior to the neck- called thoraco-lumbar fascia
  4. Intrinsic back muscle nerve supply
    dorsal rami of spinal nerves
  5. Muscle which runs form cervical and thoracic spinous processes to upper ribs and can pull these ribs upward
    Serratus posterior superior
  6. Muscles which runs from thoracic and lumbar spinous processes to lower ribs, and can pull these ribs downward
    Serratus posterior inferior
  7. Intrinsic back muscle which passes from one spine to the next and assist in extending the vertebral column
    Interspinalis mm
  8. Two most basic movements of the skeleton
    flexion and extension

    • flexion=fetal position
    • extension=opposite direction
  9. Intrinsic back muscle which passes from one transverse process tothe next and assist in laterally flexing the vertebral column
    intertranservarii mm
  10. Intrinsic back muscle which passes from transverse processes to ribs and assist in elevation of the ribs during respiration and lateral flexion of the vertebral column
    levatores costarum mm.
  11. What is proprioception?
    sensing force and position, allow stabilization; this is the function of the intrinsic back muscles
  12. What is the transversospinalis?
    Group of mm which run from transverse to spinous processes
  13. Name the transversospinalis
    • rotatores-attach inferiorly on transverse processes and superiorly on spinous processes (pass 1-2 intervert spaces)
    • multifidus- attach same as above, extended over more invert spaces, more prominent on lower spine
    • semispinalis-attach same as above, superior half of vert column, span more spaces (4-6), IMPORTANT in holding head up and neck straight
  14. Name the two parts of the semispinalis
    Semispinalis capitis-connects b/w transverse processes of upper thoracic vert and skull

    Semispinalis cervicis- inferiror attachments are on cervical and thoracic tranverse processes
  15. Name the muscles in the Erector spiane (also called sacrospinalis)
    iliocostalis- most lateral fibers, attaches superiorly to transverse processes and the angles of the ribs

    longissimus (the longest)- extends all the way to the skull

    spinalis- most medial, attaching superiorly and inferiorly on spinous processes
  16. Muscle which attaches spines of vert T6 and higher to the skull or to transverse processes of upper cervial vert. Acting bilaterally they extend the head and end, unilaterally they head/neck to the side
    Splenius capitis et cervicis
  17. ventral root carry?
    motor (efferent) signals
  18. Dorsal root carry only
    sensory (afferent) signals
  19. rami of spinal nerves carry
    both sensory and motor
  20. Describe signal transmission in somatic nervous system
    • 1)signal travels dorsol root-
    • 2)in gray matter of the cord synaptic transmission conveys the stim to a motor (efferent) nerve cell in ventral horn of g-matter
    • 3)signal passes through ventral root to skeletal
    • *Brain intervention is not necessary
  21. segment of skin recieving branches from one parin of spinal nerves is called
    dermatome- remember spinal nerves overlap in these areas
  22. Number of pairs of spinal nerves
    • 31
    • 8
    • 12
    • 5
    • 5
    • 1
  23. Cervical spinal nerves emerge
    above the number of the same vert; e.g. C1 emerges above C1(atlas) and skull except C8 emerges below C7 and above T1

    • Remember- each thoracic, lumbar, and sacral nerve pass through the intervert formamen below the vert the the same number
    • Remmeber- there are no intervert foramen below the last sacral vert, so S5 and Co1 pass through the sacral hiatus
  24. What is the posterior ramus of C1 called?
    suboccipital nerve- emerges in the center of the triangle and supplies the 3 muscles that form the suboccipital triangle, plus the rectus capitis minor m
  25. What is the posterior ramus of C2 called?
    greater occipital nerve- it passes throgh the superificial aspect of the suboccipital triangel en route to the skin on the back of the head.
  26. Waht is a spinal cord segment?
    is that part of the cord that gives rise to a particular spinal nerve (so there are 31 segments in the cord, numbered like the nerves), but the spinal cord level does not equal vertebral level
Card Set
Gross Anatomy
Muscles and Nerves of the Back