Back Flashcards
During a lumbar puncture what are the layers in which the needle passes through.
Skin->superficial fascia ->deep fascia->supraspinous ligament ->interspinous ligament -> inter laminar space ->epidural space ->dura ->arachnoid -> subarachnoid space
Purpose of lumber puncture and location.
Lumbar puncture is used t inject anesthetic material in the epidural space or to withdrawal CSF from the subarachnoid space. L4-L5 interspace. Top of the iliac crest.
Typical Vertebra
consists of an anterior body and a posterior vertebral arch consisting of 2 pedicles and 2 laminae.
Intervertebral Foramina
Formed by vertebral notches and provide for and exit of the spinal nerves.
Dorsal projection spines &lateral projecting transverse processes
Attachment site for muscles and ligaments.
Intervertebral disks
Form cartilaginous joints between the vertebral bodies and provide limited movements between the individual vertebrae.
Annulus Fibrosus
consists of the outer concentric rings of fibrocartilage and fibrous connective tissue.
Nucleus pulposus
Shock absorber.Postnatal remnant of the notochord.
Herniation of a nucleus pulpous
Common in a posterolateral direction.
Anterior Longitudinal ligament
Prevents hyperextension of the vertebrae and is often involved in “whiplash” accidents.
Posterior Longitudinal Ligament
limits flexion of the vertebral column.Causes herniation of a disc to be positioned poster laterally.
Describe sciatica.
A radiating pain along the spine .The nucleus pulpous herniates through the annulus fibrosis and compresses the spinal nerve roots.
Occurrence site of herniations.
Lower lumber =L4/L5 or L5/S1
Lower cervical= C5/C6 or C6/C7
Intervertebral Foramen boundaries
Anterior : bodies of the vertebrae and intervertebral disks.
Posterior : Zygapophyseal joint and articular processes.
Superior and inferior : Pedicles of the vertebrae.
Order of the Meninges
vertebral body ->epidural space ->dura mater ->sub-dural space -> arachnoid mater -> subarachnoid mater -> Pia mater
Pia mater
- attached to the surface of the spinal cord.
- terminates at L1 or L2 vertebral levels in the adult
Denticulate Ligament
separates the ventral and dorsal roots of the spinal nerves and anchor to the dura mater.
Filum Terminale
- part of the cauda equina
- ventral and dorsal roots of lumbar and sacral nerves.
Dura Mater
- tough, cylindrical covering
- envelops the entire spinal cord and caudal equina.
- continue through the foramen magnum and is continuous with the meningeal layer of the cranial dura.
Arachnoid Mater
Lines the inner surface of the dura mater and dural sac.
-Terminates at th 2nd sacral vertebra.
Epidural Space
contains fat and the internal vertebral venous plexus
Internal vertebral plexus
Valveless and connects with veins of the pelvis , abdomen , and thorax. Route of metastasis of cancer.
Subarachnoid space
- Pressurized space located between the arachnoid and Pia mater layers.
- Contains CSF
L1/ L2
-inferior limit of the spinal cord in adult. (Conus medullaris)
S2
Inferior limit of the dural sac and the subarachnoid space.
Number of spinal nerves.
31 pairs
List of spinal nerves .
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
Dorsal root
- Carries sensory fibers
- dorsal root ganglion contains the pseudo unipolar cell.
Ventral root
- motor neurons
- located in the ventral or lateral horns of the spinal-cord gray matter.
Spinal nerve
Formed by the union of the ventral and dorsal roots.
Dorsal rami
-Innervates the skin of the dorsal surface of the back, neck, zygapophyseal joints , and intrinsic skeletal muscles of the deep back.
Ventral rami
-innervates the skin of the anterolateral trunk and limbs.
