Week 2 Spine Intrinsic Back & Suboccipital Triangle Bones & Joints of the Lower Limb Lumbar Plexus & Posterior Abdominal Wall Muscles Gluteal Region, Thigh, Femoral Triangle, Knee & Leg Foot

Skeletal Components

• The skeletal components consist of:
  • Skull
  • Vertebrae
  • Ribs
  • Hips
  • Sacrum

Vertebrae

• Key features of vertebrae:
  • Vertebral foramen: A hole for the spinal cord.
  • Spinous process: Projects posteriorly.
  • Lamina: Connects the spinous process to the transverse process.
  • Transverse process: Projects laterally.
  • Pedicle: Connects the transverse process to the body.
  • Body (Centrum): The main weight-bearing structure.

Spinal Regions

• Vertebral column divided into:
  • Cervical: C1-C7
  • Thoracic: T1-T12
  • Lumbar: L1-L5
  • Sacral: S1-S5 (fused)
  • Coccygeal: Coccyx

Spinal Curvature

• Spinal column exhibits natural curves:
  • Cervical Lordosis: Concave curvature in the cervical region.
  • Thoracic Kyphosis: Convex curvature in the thoracic region.
  • Lumbar Lordosis: Concave curvature in the lumbar region.
  • Sacral Kyphosis: Convex curvature in the sacral region.

Cervical Vertebrae

• Characteristics:
  • C1-C7 are cervical vertebrae.
  • C7 is also known as the vertebra prominens (easily palpable).

Features of Cervical Vertebrae

• Distinguishing features:
  • Superior and inferior articular processes (and facets).
  • Transverse foramen: A hole in the transverse process for the vertebral artery.
  • C6 is used as an example.

Special Cervical Vertebrae (C1 & C2)

• Atlas (C1):
  • Posterior arch.
  • No vertebral body.
• Axis (C2):
  • Dens (odontoid process) for articulation with C1.
  • Anterior arch.

Thoracic Vertebrae

• Characterized by:
  • Superior costal facet: For articulation with the rib.
  • Inferior costal facet: For articulation with the rib.
  • Transverse costal facet: For articulation with the rib on the transverse process.
  • Facet: Little face

Rib Articulation

• Thoracic vertebrae are characterized by the presence of rib articulation facets.

Lumbar Vertebrae

• Characterized by:
  • Large vertebral bodies.
  • Intervertebral foramen: For the passage of spinal nerves.

Spinal Nerves

• Components:
  • Dorsal root: Carries sensory information.
  • Dorsal root ganglion: Contains cell bodies of sensory neurons.
  • Ventral root: Carries motor information.
  • Spinal nerve: Formed by the union of dorsal and ventral roots.
  • Dorsal ramus: Innervates the back.
  • Ventral ramus: Innervates the limbs and anterior trunk.
  • Intervertebral foramen: Where spinal nerves exit the vertebral column.

Intervertebral Discs

• Components:
  • Anulus fibrosus: Outer fibrous ring.
  • Nucleus pulposus: Gelatinous core.

Sacrum and Ilium

• Key features:
  • Iliac crest: Superior border of the ilium.
  • Iliac tubercle: Prominence on the iliac crest.
  • Posterior superior iliac spine (PSIS).
  • Posterior inferior iliac spine.
  • Sacral hiatus: Opening at the inferior end of the sacrum.
  • Median sacral crest: Ridge along the midline of the sacrum.

Joints

• Joints of the vertebral column:
  • Costovertebral: Rib articulation with vertebrae.
  • Sacroiliac: Sacrum articulation with the ilium.
  • Atlantooccipital: Atlas (C1) articulation with the occipital bone.
  • Atlantoaxial: Atlas (C1) articulation with the axis (C2).
  • Intervertebral: Between vertebral bodies.
  • Zygapophyseal (Facet joints): Between articular processes.
  • Lumbosacral: L5 articulation with the sacrum.

Spinal Nerves

• Cauda Equina: Collection of nerve roots that descend from the spinal cord.

Spinal Nerves - C1-T12

• Spinal Nerves:
  • C1 Exits above C1 vertebra
  • C8 Spinal nerve exits below C7 vertebra.
  • There are 8 cervical nerves but only 7 cervical vertebrae

Spinal Cord Enlargements

• Cervical enlargement: C4 - T1 (Brachial Plexus)
• Lumbar enlargement: T11 - L1 (Lumbar Plexus)

Spinal Cord Termination

• Conus medullaris: Termination of the spinal cord.

Spinal Cord Coverings

• Filum terminale internum: Extends from the conus medullaris.
• Filum terminale externum
• Termination of spinal dura mater