Back Flashcards
Functions of the vertebral column
- Protection
- Support (the axial skeleton)
- Posture and locomotion
Limit vertebral column movements
- IV discs
- Facets
- Ligament flava, posterior longitudinal ligament
- Thoracic cage attachments
Extrinsic back muscles - Innervation
ventral rami - because responsible for limb movement
Trapezius is the exception
Superficial Extrinsic Back Muscles
- Trapezius
- Latissimus dorsi
- levator scapulae
- rhomboid: major and minor
Intermediate Extrinsic Back Muscles
-Serratus posterior superior
-Serratus posterior inferior
function as superficial respiratory (proprioceptive) muscles
Trapezius - actions
(superior and inferior fibers) cause superior rotation of scapula.
elevation, depression, retraction of scapula.
Latissimus Dorsi - actions
Extends, adducts, medial rotation of shoulder joint.
Swimmers’ muscle.
Lattissimus Dorsi - innervation
Thoracodorsal Nerve (C6, C7, C8)
Lattissimus Dorsi - irrigation
Thoracodorsal artery
Rhomboids - action
Inferior rotation of scapula
Levator scapulae - action
Elevates scapula
Levator scapulae - innervation
Dorsal scapular nerve (C5)
Cervical Spinal nerve (C3-C4)
Levator scapulae - irrigation
Dorsal scapular artery
Rhomboids - innervation
Dorsal scapular nerve (C4, C5)
Trapezius - innervation
Cranial nerve XI
Deep intrinsic back muscles
Actions: maintain posture, control movement of vertebral column
Innervation: Posterior (Dorsal) Rami Spinal Nerves
Cervical Movements
Flexion, Extension, Lateral flexion, rotation
Superficial Intrinsic Back Muscles
Splenius (Capitis, Cervicis)
Splenius (Capitis, Cervicis) - actions
alone: laterally flex neck, rotate head
together: extend head and neck
Splenius Capitis - insertions
Spinous process C7-T4, mastoid process occipital bone
Splenius Cervicis - insertions
Spinous processes T3-T6, Transverse processes C1-C3
Intermediate Intrinsic Back Muscles
Erector Spinae (Iliocostalis, longissimus, spinalis)
Erector Spinae - actions
Chief Extensors of Vertebral Column
Bilaterally- Extend vertebral column and head
Unilaterally- Laterally flex vertebra column
Erector Spinae muscles
Iliocostalis (lateral)
Longissimus (intermediate)
Spinalis (medial)
Transversospinalis Muscles
EXTENSION, ROTATION
Semispinalis (Capitis, cervicis, thoracis)
Multifidus
Rotatores
Semispinalis - actions
(Capitis, Cervicis, Thoracis)
Extend head, thorax and cervical region
Multifidus - action
Thickest in the lumbar region; stabilizes vertebrae
Rotatores
Thoracic region: Stabilizes vertebrae
Minor Deep Intrinsic Back Muscles
Interspinalis
Intertransversarii
Levatores Costarum
Interspinalis
Innervation: Posterior Rami Spinal Nerve
Action: aid in extension and rotation VC
Intertransversarii
Innervation: Anterior AND Posterior Rami Spinal Nerve
Action: aid in lateral flexion, bi-laterally stabilize VC
Levatores Costarum
Innervation: Posterior Rami Spinal Nerve
Actions: Elevate ribs, assist respiration, aid lateral flexion
Joints of the Vertebral Column
- Vertebral body joints - IV discs
- Vertebral arches joints - facet joints, uncovertebral joints
- Craniovertebral joints - Atlanto-axial, Atlanto-occipital
- Sacroiliac joints
Intervetebral discs
Symphyses, named for adjacent vertebrae
No discs between C1 and C2 (dens instead) or within saccrum/ coccyx
Annulus fibrosus
alternating laminae of fibrocartilage (of the IV discs)
Nucleus pulposus
Hydrophilic, jelly-like center of IV discs.
Facet (zygopophysial) joints
Synovial joints, surrounded by facet capsulary ligament
Innervated: articular branches from medial branches of dorsal rami spinal nerves- have sensory component
bone spurs occur in these joints- will manifest as pain in diff dermatomes innervated by those spinal nerves
Limit spinal flexion
Ligamentum flavum
Posterior longitudinal ligament
Supraspinous and interspinous ligaments
Limit spinal extension
anterior longitudinal ligament
Limiting lateral bending
Intertransverse Ligaments
Craniovertebral joints
One median atlantoaxial joint, two lateral
Sacroiliac Joints
primary joints of the pelvis; weight-bearing function
Sprain
ONLY ligaments/attachments to bones are involved
NO dislocation/ joint instability
Strain
Stretching/ muscle microtear
Erector spinae muscles
Most common cause of back pain
Suboccipital region muscles
- Obliquus capitis inferior (no attachment to cranium)
- Obliquus capitis superior
- Rectus capitis posterior major
- Rectus capitis posterior minor
Suboccipital region muscles - actions
Extend head on C1, rotate head and C1 on C2
Stabilize and control fine movements
Suboccipital region muslces - innervation
suboccipital nerve (posterior ramus C1)
Suboccipital region muscles - insertions
- OC inferior- spinous process of c2 - transverse process C1
- OC superior - transverse process C1 - occipital bone
- RCP major - spinous process c2 - occipital bone
- RCP minor - c1 - occipital
Suboccipital triangle - irrigation
Vertebral artery
