Vertebral Column; Spinal Cord & Meninges PDF

Vertebral Column; Spinal Cord and Meninges BiBi Singh, DPM September 27, 2024 Objectives Explain and review the vertebral column. Describe joints of the vertebral column. Explain ligaments of the vertebral column. Describe the makeup of a spinal nerve. Describe the cours...

Vertebral Column; Spinal Cord and Meninges BiBi Singh, DPM September 27, 2024 Objectives Explain and review the vertebral column. Describe joints of the vertebral column. Explain ligaments of the vertebral column. Describe the makeup of a spinal nerve. Describe the course and function of the dorsal rami of spinal nerves that serve the back. Ligaments of the Vertebral Column Anterior longitudinal ligament Posterior longitudinal ligament Ligamentum flava Supraspinous ligament Interspinous ligament Anterior longitudinal ligament From the anterior tubercle of the atlas to the sacrum Attached to the front of the vertebral bodies and disc Posterior longitudinal ligament From the occipital bone of the skull to the sacrum Lies within the vertebral canal Ligamentum flava Between the laminae Supraspinous ligament On top of the spine Interspinous ligament Between spines Vertebral arches Synovial joints between articular processes Zygapophyseal joints Allow gliding movements between facets Spinal Cord – Spinal Nerves Found in the Vertebral Column (Canal) Continuous with the brain stem 31 Pairs of Spinal Nerves 8 Cervical Nerves ( 7 vertebrae) 12 Thoracic Nerves 5 Lumbar Nerves 5 Sacral Nerves 1 Coccygeal nerve (4 vertebrae) Spinal Cord Spinal cord ends at L2 Conus medullaris ends at L2 Cauda equina (looks like a horse's tail) Made up white and gray matter Filum terminale is from L2 - Co Embryology of the Spinal Cord Fetus Spinal Cord is attached to the coccyx at 8 weeks Differential growth between spinal cord and vertebral column Newborn The spinal cord level at Lumbar vertebra 3 Adult The spinal cord ends at LV 1 and LV 2, but never lower than LV 2 Cervical Nerves Cervical Nerve 1 Exits the vertebral Column between the skull and the atlas Superior to or above its corresponding vertebra This nerve is called the suboccipital nerve Dorsal ramus present No Dorsal root Cervical Nerves Cervical nerves 2,3,4,5,6,7 Exit above their corresponding vertebrae Cervical Nerve 8 Passes below or inferior to cervical vertebra 7 Exits between CV 7 & TV1 Relationship of vertebral column, spinal cord segments, spinal nerves and ganglia A. At 12 weeks gestation, the spinal cord is the same length as the vertebral column. B. The relation of the spinal cord segments (the numbered segments) and spinal nerves and ganglia to the adult vertebral column. Greater growth of the vertebral column has made the spinal cord is shorter by comparison. Now spinal nerves must descend increasingly farther within the vertebral canal to reach the intervertebral foramen by which they exit. Lumbar and sacral spinal nerves extend inferior to the level of the cord, forming the cauda equina Spinal Cord Position In the embryo, the spinal cord extends the entire length of the vertebral column and the spinal nerves pass through the intervertebral foramina at their levels of origin. Because the vertebral column and the dura mater grow at a faster rate than the spinal cord the caudal end of the cord comes to lie at higher levels as development continues. During the sixth month of gestation the caudal tip of the cord lies at the level of S1 vertebra. At birth it lies at the L3 level while in the adults it ends between L1 and L2. As a result of different rates of growth, the spinal roots run obliquely from the cord to their corresponding vertebra level. The nerve roots below the caudal end of the cord from a bundle of nerve roots called the cauda equina. Meninges Coverings of the brain & Spinal Cord from external to internal Epidural Space Dura mater Subdural space Arachnoid mater Subarachnoid space CSF (Cerebrospinal fluid) Pia mater Brain or Spinal Cord Lumbar Puncture Spinal Cord ends at LV 2 Subarachnoid sac ends at SV 2 Lumbar Puncture is done at LV 4 in the Median or Lateral Plane Lumbar Puncture Lateral Plane Median Plane Skin Skin Transverso – spinal muscle Supraspinous ligament (Multifidus) Interspinous ligament Ligamentum flava Interspinalis Dura mater Dura mater Arachnoid mater Arachnoid mater Subarachnoid mater (CSF) Subarachnoid sac (CSF) Epidural Analgesia ( during parturition) Inject between lumbar laminae or sacral hiatus Nerves Thoracic nerves Pass below the corresponding vertebre Lumbar nerves Pass below the corresponding vertebrae Sacral and coccygeal nerves Pass below the corresponding vertebrae Coverings of the Spinal Cord Membrane or Meninges Layers: Vertebral body (bone) Epidural space Fat is a major component Vertebral venous plexus Spinal nerves Dura mater Subdural space Arachnoid mater Subarachnoid space (CSF) Contains the cerebral spinal fluid Pia mater Spinal cord Layers of the Spinal Cord – Dura mater Fibrous sheath Ends at S2 and then becomes filamentous and surrounds the filum terminale as the dura of the filum which then attached to the coccyx Spinal cord ends at L2 S2 ends as a sac form, but continues as a layer around filum terminale Layers of the Spinal Cord – Arachnoid mater Ends at S2 Subarachnoid space has CSF on top of spinal nerves Layers of the Spinal Cord – Pia mater Closely investing the cord Lateral projection between the dorsal and ventral roots of the spinal nerves called denticulate ligaments, which are: Triangular in shape A surgical landmark At conus medullaris continues as a thread The filum terminale which attaches to the coccyx Made of pia mater Fom L2 – S2 – the filum terminale is made of pia mater Pia mater ends in its sac form at From S2 – coccyx Filum terminale is made of pia mater and dura mater. From the level of S2 to coccyx the filum terminale picks up a layer of dura mater to give it strength Layers of the Spinal Cord – Subarachnoid Sac & Epidural Space Epidural space – Bone & Dura Mater Blood Supply of the Spinal Cord Anterior Spinal Artery from the Vertebral artery Anterior Median Sulcus Segmental Arteries Two Posterior Spinal Arteries from the Vertebral Artery Lateral to Posterior Medial Sulcus of the spinal cord Radicular Artery from the Intermediate Neural Artery Venous Drainage of the Spinal Cord Veins Drain into the intervertebral veins then into the segmental veins or the vertebral venous plexus Vertebral Venous Plexus Found in epidural apce It is a valveless system, blood can flow in either direction Drains into the superior sagittal sinus of the brain coverings Questions to Ponder A slipped disc between L4 and L5, which spinal nerve is affected? L5 A slipped disc between L5 and S1, which spinal nerve is affected? S1