Disclosure Statement of Financial Interest I, Dr. Tom Kwasigroch, DO NOT have a financial interest/arrangement or affiliation with one or more organizations that could be perceived as a real or apparent conflict of interest in the context of the subject of this presentation. Vertebral Column, Back and Spinal Nerve Objectives –we will discuss: Disclosure Statement of Unapproved/Investigative Use I, Dr. Tom Kwasigroch, DO NOT anticipate discussing the unapproved/investigative use of a commercial product/device during this activity or presentation. • • • • Configuration of the vertebral column Characteristics of types of vertebrae Intervertebral discs and ligaments Muscles of the back – Extrinsic – Intermediate – Intrinsic (superficial, intermediate and deep) • Central Nervous System components • Spinal cord and spinal nerve blocks 1 Pre Test Item 1 How does the configuration of the vertebral column in the newborn differ from the adult?? Vertebral Column Secondary Curvature Spinous Process Transverse Process Pedicle Primary Curvature Transverse Process Pedicle Secondary Curvature Body Spinous Process Body Primary Curvature Superior and Inferior Articular Processes 2 CV1: No Spinous Process No Vertebral Body Dens on CV2 7 Cervical vertebrae All Cervical Vertebrae: Bifid Spinous Processes Nearly Horizontal Articular Processes Transverse Foramen (Vertebral a) Vertebral artery coursing through transverse foramina of CV 6 – CV 1 3 Thoracic Vertebrae: 12 Thoracic vertebrae Long, Sharp, Oblique Spinous Proces Articular Processes for Ribs (on TP and side of body) 5 Lumbar vertebrae 4 Lumbar Vertebrae: Large Vertebral Bodies Large, Block-like Spinous Processes Vertically-oriented Articular Processes Anterior Sacral Foramina (Ventral Rami) 5 fused Sacral vertebrae 5 Posterior Sacral Foramina (Dorsal Rami) Posterior Sacral Foramina Anterior Sacral Foramen Sacral Hiatus Pre Test Item 2 If the LV4/5 disk herniates what is most at risk of damage?? 4 Fused coccygeal elements 6 Vertebral Column Cross Section with Intervertebral Disc Annulus Fibrosis Nucleus Pulposus Annulus Fibrosis Subarachnoid Space Nucleus pulposus Epidural Space Intervetebral Disc Intervetebral Foramen PLL (Posterior Longitudinal Ligament) ALL (Anterior Longitudinal Ligament) 7 Back Muscles Lig. Flavum Supraspinus Lig. Interspinous Lig. Spinal Accessory nerve - CNXI Extrinsic muscles: Extrinsic muscles (cont): Thoracodorsal nerve - C6,7,8 8 Extrinsic muscles (cont): Levator scapulae – C3,4 Rhomboideus minor Rhomboideus major Dorsal Scap n. – C5 Extrinsic muscles (cont): Serratus Anterior Long Thoracic n. – C5,6,7 Intermediate muscles Ventral Root (Motor) Spinal nerve (Sensory + Motor) Ventral Ramus (S + M) (supply extrinsic mm. – usually via Brachial Plexus) Dorsal Root (Sensory) (w DRG) Dorsal Ramus (S + M) 9 Ventral Root Ventral Root Ventral Ramus Ventral Ramus (Intermediate back mm., usually through Intercostal nn.) Dorsal Ramus Dorsal Root (w DRG) Intrinsic muscles Superficial layer: Splenius Cervical and upper thoracic Dorsal Rami Dorsal Ramus Dorsal Root (w DRG) (Intrinsic back mm., segmentaly) Intrinsic muscles (cont) Intermedate layer: Erector Spinae Muscle Spinalis Segmental Dorsal Rami 10 Erector Spinae Muscle - Erector Spinae Muscle - Longissimus Iliocostalis Segmental Dorsal Rami Segmental Dorsal Rami Deep layer of Intrinsic muscles: Transversospinal muscles Semispinalis Segmental Dorsal Rami Dorsal Rami (Supply ALL intrinsic muscles – Erector Spinae and Transversospinal, etc. ) 11 Deep layer of Intrinsic muscles: Deep layer of Intrinsic muscles: Transversospinal muscles - Transversospinal muscles - Multifidus Rotatores Segmental Dorsal Rami Segmental Dorsal Rami Dorsal Rami Dorsal Rami – cutaneous branches (Supply ALL intrinsic muscles – Erector Spinae and Transversospinal, etc. ) 12 Dorsal Rami Cutaneous Supply (all else via Ventral Rami) Cutaneous branches of Dorsal Rami (meet up with cutaneous branches of vertral rami to form dermatome pattern) Central nervous System Components: •Spinal nerve •Spinal cord •Vascular supply Dorsal Root Ventral Root Dorsal Ramus Ventral Ramus Spinal Nerve Spinal Segment 13 Six Spinal Segments – pairs of spinal nerves Dura Arachnoid Subarach Space (CSF) Pia Denticulate Lig Brain with Attached Spinal Cord Brain with Attached Spinal Cord Spinal Cord Segment (C3) Roots of Brachial Plexus (C5-T1) Roots of Brachial Plexus (C5-T1) 14 Sensory Innervation to Face?? CN V1 Dermatome – area of skin supplied by a single spinal segment CN V2 Spinal Segments: CN V3 The spinal cord has 31 spinal segments, giving rise to 31 pairs of spinal nerves 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal How does that numbering affect the location of the nerves as they exit the vertebral column?????????????????? (Remember, 7 cervical vertebrae and 8 cervical spinal nerves) Cervical nerves exit ABOVE the same numbered vertebra e.g., C1 above CV1, C4 above CV4 C8 exits below CV7, since there are only 7 cervical vertebrae and 8 cervical nerves How does that numbering affect the location of the nerves as they exit the vertebral column?????????????????? Cervical nerves exit ABOVE the same numbered vertebra e.g., C1 above CV1, C4 above CV4 Inferior extent of spinal cord: LV 1-2 in adult, LV 3 in infant All other levels nerves exit BELOW the same numbered vertebra All other nerves exit BELOW the same numbered vertebrae Inferior extent of dura and subarachnoid space is SV 3 e.g., L4 below LV4 S5 and Co1 exit through sacral hiatus 15 Vertebral Column/Spinal Cord Dissection Spinal Cord in Dural Sheath Conus Medularis (lowest elements of the spinal cord, e.g., sacral and coccygeal spinal segments) Filum Terminale (Pia continuing off the end of the spinal cord – tethers the cord to the coccyx as the coccygeal ligament, after piercing the dura) Some of the Numerous Spinal Nerves Exiting the Vertebral Column LV1 Intervetebral Disc LV2-3 Intervetebral Disc Intervetebral Foramen Intervetebral Foramen Spinal Nerve L4 (LV3-4) LV 4-5 Disc Herniation LV4 Pedicle Spinal Nerve L5!! Spinal Nerve L4 LV4-5 Disc Herniation?? Spinal Nerve L5!! 16 Blood Supply to the Brain and Spinal Cord LV4-5 Disc Herniation Vertebral artery has anterior (1) and posterior (2) branches which supply the spinal cord Brain with Attached Spinal Cord Ant. Spinal Artery Post. Spinal Arteries Segmental Medullary aa. augment the blood in the spinal aa. Basilar Artery (formed by union of vertebral arteries) Right Vertebral Artery Left Vertebral Artery 17 18