DSF Anatomy of Back Flashcards
Function of ligaments connecting adjacent vertebrae
Resist hyperflexion
Lumbar puncture
Targets subarachnoid space to remove CSF
Pierces dura & arachnoid mater
Around L4
Epidural anesthesia
Targets epidural space to apply anesthetic to nerve roots
Does not pierce dura & arachnoid mater
Spinal meninges
Dura mater
Arachnoid mater
Pia mater
Pia Mater
Denticulate ligaments: anchor spinal cord to superficial meningeal layers
Filium terminale: extension of Pia Mater that connects spinal cord to coccyx - provides tension to stabilize the spinal cord
Meningeal spaces
Epidural space: located b/w periosteum lining vertebral canal and dura mater
Subarachnoid space: located b/w arachnoid mater and pia mater, contains CSF
*No naturally-occurring “subdural space”
Intrinsic back muscles
Deep (Splenius, erector spinae, transversospinales)
*Only has attachments and/or function w/in vertebral column
Extrinsic back muscles
Intermediate (respiratory) and Superficial (appendicular)
*At least 1 attachment outside the vertebral column and has appendicular respiratory function
Splenius muscles
Deep (intrinsic)
Splenius Capitis
Splenius Cervicis
Splenius Capitis
Deep (intrinsic)
Innervation: Posterior rami of cervical spinal nerves
Bilateral extension of head and neck; ipsilateral rotation of head
PA: ligamentum nuchae, spinous processes C7-T4
DA: mastoid process, skull
Splenius Cervicis
Deep (intrinsic)
Innervation: Posterior rami of cervical spinal nerves
Bilateral extension of head and neck; ipsilateral rotation of head
PA: spinous processes of T3-T6
DA: transverse processes of C1-C3
Erector Spinae muscles
Iliocostalis
Longissimus
Spinalis
Innervation: posterior rami of spinal nerves
Bilateral extension of trunk/spine; unilateral lateral flexion of trunk
Deep back muscles
*Intrinsic Splenius Erector spinae Transversospinales *Function: extension/flexion, lateral flex/extend, rotation
Conus Medullaris
Distal end of spinal cord
Adults: to L1-L2
Neonates: L3-L4
Transversospinales
Deep (intrinsic) back muscles
Innervation: posterior rami of spinal nerves
Semispinalis: extension, contralateral rotation
Multifidus & Rotatores: stabilization, local movements
Intermediate muscles: Serratus Posterior
Innervation: intercostal nerves (anterior rami of spinal nerves)
Superior: elevates superior ribs during inspiration
Inferior: depresses inferior ribs during expiration
Superfical (Appendicular Muscles)
Trapezius Latissimus Dorsi Levator Scapulae Rhomboid Major + Minor *All innervated by branches of the brachial plexus (anterior rami of C5-T1), except for the trapezius, which is innervated by the 11th CN
Trapezius
Superficial (Appendicular)
Innervation: accessory CN XI
Upper fibers: elevate & upwardly rotate scapula
Middle fibers: retract scapula
Lower fibers: depress & upwardly rotate scapula
Latissimus Dorsi
Superficial (Appendicular)
Innervation: Thoracodorsal n. (anterior rami of C6-C8)
Flexion, adduction, medial rotation of arm; pull body upward when climbing
Levator Scapulae and Rhomboids
Superficial (Appendicular) Innervation: Dorsal Scapular n. (anterior ramus of C5) Downward rotation of scapula Levator: elevate scapula Rhomboids: retract scapula
What back muscles are innervated by posterior rami?
Deep (intrinsic)
Splenius
Erector spinae
Transversospinales
What back muscles are innervated by anterior rami?
Intermediate (Serratus posterior)
Superficial (Trapezius, Latissimus Dorsi, Levator Scapulae, Major and Minor Rhomboids)
(Extrinsic)