BACK Spinal cord and Nervous system

BACK UNIT OVERVIEW Spinal cord & Nervous system review Meninges and CSF Vasculature Skeletal structures / joint surfaces Ligamentous support Musculature

BACK OBJECTIVES Describe the gross anatomy for each system (circulatory, muscular, nervous, and skeletal) in the region of the back. Integrate the systems to discuss the vertebral column functions. Analyze common dysfunctions in the vertebral column. For each muscle, describe how the attachment sites result in an action around a joint. For each muscle, identify the innervation (peripheral nerve and nerve roots).

GENERAL SKELETAL STRUCTURE Lordosis vs. Kyphosis Joints – vertebral discs & zygapophysial joints Movements

VERTEBRAL SPINE DEVELOPMENT Size (height) of vertebrae

SPINAL CORD DEVELOPMENT Spinal cord level vs. vertebral level

LUMBAR CISTERN Filled with CSF Begins at L2 Contains cauda equina & internal filum terminale Site of epidural anesthetic Subarachnoid Space

NERVOUS SYSTEM OVERVIEW Central nervous system Peripheral nervous system Dermatomes and myotomes

NERVOUS SYSTEM OVERVIEW CONT’D Dorsal (posterior) and ventral (anterior) rami (ramus) Spinal nerve roots vs peripheral nerves Plexi (plexus)

AUTONOMIC VS SOMATIC Functional divisions Autonomic and somatic nerves throughout CNS and PNS

SPINAL CORD MENINGES Dura Mater Arachnoid Mater Pia Mater Epidural, Subdural, Subarachnoid spaces

WHICH OF THE FOLLOWING IS INCORRECT PERTAINING TO THE LUMBAR CISTERN? A.It contains CSF. B.It contains the cauda equina. C.It contains the internal filum terminale. D.It typically begins in adults at L2. E.It contains epidural fat.

THE C1 SPINAL CORD SEGMENT IS LINED UP WITH THE C1 VERTEBRA, EVEN THOUGH IT IS NOT LINED UP IN THE LUMBAR REGION. A.True B.False

A.They all do B.They all do not C.They do above C8 D.They do below C8 THE SPINAL NERVES EXIT THE INTERVERTEBRAL FORAMEN BELOW THE CORRESPONDING NUMBERED VERTEBRA.

VASCULAR SUPPLY Vertebrae Back muscles Spinal cord

BLOOD SUPPLY OF VERTEBRAE

WHICH OF THE FOLLOWING IS INCORRECT PERTAINING TO THE NEUROVASCULAR SUPPLY OF THE VERTEBRAL COLUMN? A.The vertebral bodies are supplied exclusively by the anterior and posterior spinal arteries. B.Venous drainage is to both internal (within the vertebral canal) and external venous plexuses. C.Zygapophyseal joints are supplied by medial branches of posterior rami of spinal nerves. D.Pain fibers from the ligamentum flavum are conveyed by (recurrent) meningeal branches of spinal nerves. E.Proprioceptive fibers from the anterior longitudinal ligament are conveyed by (recurrent) meningeal branches of spinal nerves.

SKELETAL STRUCTURES – THE BACKBONE Physiological properties General vertebral shape

CERVICAL REGION Intervertebral foramina Uncus (uncinated processes) Bifid spinous processes Angles of zygapophysial joints

VERTEBRAL ARTERY Travels up in transverse foramina Loops over C1 in groove for vertebral artery Merges ventral to Pons to form Basilar artery Supplies brainstem, cerebellum, and posterior cerebrum

ATLAS AND AXIS Atlantoaxial joint

INTERPRETING LATERAL VIEW CERVICAL RADIOGRAPHS

JEFFERSON (BURST) FRACTURE

HYPERFLEXION WITH HERNIATION Disc herniation – nucleus pulposis squeezed posteriorly

OTHER VERTEBRAL INJURIES Hyperextension (whiplash) Hangman’s fracture

RUPTURE OF TRANSVERSE LIGAMENT OF ATLAS

WHICH OF THE FOLLOWING IS INCORRECT PERTAINING TO THE VERTEBRAL ARTERY? A.It traverses the transverse foramina of the cervical vertebrae. B.If partially occluded, it can cause dizziness upon turning the head. C.It traverses a groove on the posterior arch of the atlas. D.It only has branches that supply the brain.

IN THE FOLLOWING IMAGE OF A LATERAL RADIOGRAPH OF THE CERVICAL PART OF THE VERTEBRAL COLUMN, THE ARROW POINTS TO A FRACTURE OF THE: A.pars interarticularis of the axis (hangman's fracture). B.posterior arch of the atlas. C.lamina of the atlas. D.spinous process of C3. E.occipital condyles.

LIGAMENTOUS SUPPORT OF ATLANTOAXIAL JOINT Ligaments to hold atlantoaxial joint together:  Cruciate ligaments (superior band, transverse, inferior band)  Alar ligaments aka apical ligament (dens to occiput)  Zygapophyseal articular capsule  Atlanto-axial membranes  Tectorial membrane