Intrinsic back muscles and vasculature Flashcards
Proximal attachments of splenius capitus?
Spinous processes of vertebrae C7-T3, nuchal ligament
Distal attachments of splenius capitus?
Mastoid process
Proximal attachments of splenius cervicis?
Spinous processes of T3 – T6 vertebrae
Distal attachments of splenius cervicis?
Transverse processes of C1 – C3 vertebrae
What are intrinsic back muscles innervated by?
Dorsal rami
Main actions of splenius capitis and cervicis?
Bilateral: Extends head/neck
Unilateral: Lateral flexion and rotation of head (ipsilateral)
Erector spinae is made up of what three muscles?
- Spinalis
- Spinalis thoracis, cervicis, capitis
2. Longissimus - Longissimus thoracis, cervicis, capitis
3. Iliocostalis
Iliocostalis lumborum, thoracis and cervicis
- Spinalis thoracis, cervicis, capitis
Proximal attach for spinalis?
c7-L2 approx
Proximal attach for longissimus?
C4 - posterior iliac crest
Iliocostalis proximal attach?
ribs 3-12 down to medial end of iliac crest
Distal attach for spinalis?
Occipital bone to spinous process of t8
Distal attach for longissimuss?
mastoid process to L5, ribs 7-12 also
Distal attach for Iliocostalis?
Transverse process of C4 to L4, also ribs 5-12
Main actions of spinalis?
Extends trunk concentrically
Main actions of longissimus?
Extends trunk, head and neck
Main actions of Iliocostalis?
Extends and ipsilaterally laterally flexes trunk and neck
Muscles that make up transversospinalis?
Semispinalis, multifidus and rotatores
What direction do the fibres of transversopspinalis muscles go in?
Oblique angle from inferior TP to superior SP
How many vertebral segments do semispinalis span?
5-7
Proximal attachments of semispinalis?
- Articular processes of vertebrae C4-C7, transverse processes of vertebrae T1-T6
Distal attachments of semispinalis?
Between superior and inferior nuchal lines of occipital bone
Spinous processes of vertebrae C2-C5
Main actions of semispinalis?
Extend and contralaterally rotates trunk, neck and head
How many spinal segments do multifidus cross?
2-5 vertebral column
proximal attachments of multifidus?
Transverse processes of cervical, thoracic, and lumbar vertebrae
Distal attachments of multifidus?
Lateral aspect and tips of the spinous processes of vertebrae 2-5 levels above origin
Action of multifidus?
Extends, contralaterally rotates and ipsilaterally laterally flexes trunk and neck
How many spinal segments to rotatores span?
1
Proximal attach of rotatores
Transverse processes of thoracic vertebrae
Distal attachments of rotatores
Laminae/Spinous process of vertebra 1 or two levels above origin
Actions of rotatores?
Stabilizer, local extension, rotation
Interspinales actions?
Extension of cervical and lumbar spine
Intertransversarii proximal and distal attachments?
Lumbar region
Actions of Intertransversarii?
Assists lateral flexion of the spine; Stabilizes spine
Levatores costarum proximal and distal attachments?
Proximal: Transverse processes of the C7 – T11
Distal: Superior border/external surface of rib one level below origin
Actions of levatores costarum?
Elevation of the ribs
Rotation of thoracic spine
Proximal attachments of Rectus capitis posterior major?
Spinous process of C2 (Axis)
Distal attachments of Rectus capitis posterior major?
Lateral part of occipital bone (inferior nuchal line)
Actions of Rectus capitis posterior major?
Extends and rotates head to the ipsilateral side
Proximal attach of Rectus capitis Posterior minor
Posterior tubercle of C1 (Atlas)
Distal attach of Rectus capitis Posterior minor
Medial part of occipital bone (inferior nuchal line)
Action of Rectus capitis Posterior minor
Extends head (stabilizes atlanto-occipital joint)
Proximal attachments of Oblique capitis Inferior
Spinous process of C2 (Axis)
Distal attachments of Oblique capitis Inferior
Transverse process of C1 (Atlas)
Action of Oblique capitis Inferior
Rotates atlas (C1) and head to the ipsilateral side
Proximal attachments Oblique capitis Superior
Transverse process of C1 (Atlas)
Distal attachments Oblique capitis Superior
Occipital bone (between superior/inferior nuchal lines)
Actions of Oblique capitis Superior
Extends head and lateral flexion to ipsilateral side
What makes the suboccipital triangle?
Rectus capitis posterior major, oblique capitis superior and oblique capitis inferior
Intrinsic back muscles (unisegmental group) is msotly for?
stabilise one segment, postural purposes
extensors of neck or head from superficial to deep
- Trapezius
- Splenius and levator scapulae
- semispinalis
- Suboccipital muscles x 4
What nerve and arteries is visible from suboccipital triangle?
Vertebral artery and suboccipital nerve (c1 posterior ramus)
What’s the two nerves below the suboccipital triangle in order?
Greater occipital nerve (c2 posterior ramus) very close to obliquus capitis inferior and 3rd occipital nerve very close to semispinalis cervicis and capitis.
Thoracolumbar fascia
- 3 layers of fascia
- connection between vertebral bodies, abdominal muscles, upper and lower limbs
- dynamic stability of lumbar spine and sacroiliac joint
What makes up the abdominal cavity?
diaphragm top, abdominal muscles side, gluteal muscles at back, pelvic floor and hip girdle below.
How is lumbar stiffened and prevented from bucking under compressive loads?
Intraabdominal pressure in abdominal cavity
Dorsal rami has two branches, medial supplies almost all muscles except two. This is supplied by the lateral branch. Which two muscles is it?
Iliocostalis and longissimus
Blood supply hierarchy for spinal cord?
- Segmental spinal arteries, exist at every spinal level
- Anterior and posterior radicular arteries
- branch off segmental at every vertebral level, supply nerve roots - Segmental medullary arteries:
- branches from segmental spinal
- appear one some levels
- Reinforce spinal arteries to supply spinal cord (booster arteries)
Vertebral venous plexuses
Internal and external vertebral venous plexuses are valveless
IVVP inside vertebral canal, EVVP outside
Both drain via intervertebral vein, exits out of intervertebral foramen and drain into segmental veins
IVVP and EVVP communicates with each other
If disc protrusion occurs between L5 and S1, what nerve root will be affected?
S1 (the nerve root one level lower will be affected)
If IV disc protrudes at c3/c4, which nerve affected?
C3, for cervical it is one level higher (nerve roots exist above their respective vertebrae)
