CONTENTS OF VERTEBRAL CANAL Flashcards
What are the contents of the Vertebral canal? (12)
- Spinal Cord
- Spinal nerve roots
- Spinal root ganglia(swelling in the dorsal root)
- Internal vertebral plexus of veins
- Fat
- Meninges
- CSF
- Radicular arteries
- Anterior and posterior spinal arteries and veins
- Posterior longitudinal ligament
- Tectorial membrane
- Transverse, cruciform, and alar ligament
What is Dura Mater?
- Outer most part of the meninges
- Forms a sac (Dural sac )
- Starts at the Foramen Magnum and ends at S2 vertebra
- The spinal dural sac is pierced by the spinal nerves and is anchored inferiorly to the coccyx by the filum terminale externum
What is the Arachnoid Mater?
- Is not attached to the Dura Mater
2. Held against the inner surface of the dura mater by the pressure of the CSF
What is the Pia Mater?
- Inferior to the conus medullaris, the pia continues as the filum terminale
- The brain and spinal
cord are intimately covered on their outer surface by the innermost meningeal layer, a delicate, transparent covering
What is the Filum terminale?
- The filum terminale
serves as an anchor for the inferior ends of the spinal cord and dural sac
*Filum terminale Internum: Pierces the caudal end of the dural sac, which acquires a layer of dura mater and becomes Filum terminale externum or coccygeal ligament
What are Denticulate ligaments?
- Prevent excessive displacement of the spinal cord
- Lateral extensions of pia mater
- Attach to the inner surface of dura mater
*About 22 extensions that attach to the dura mater
What are the 2 spaces in Spinal Meninges?
- Epidural space
2. Subarachnoid space
What is the Epidural Space?
- Loose fatty connective tissue
2. Internal vertebral venous plexus
What is the Subarachnoid Space?
- Contains CSF, spinal nerve roots, and spinal root ganglia
- Between the arachnoid and pia, is a real space that contains CSF, trabecular cells, cerebral arteries, and bridging superior cerebral veins that drain into the superior sagittal sinus
- Also, contains Aracnoid trabeculae, denticulate ligaments, Radicular arteries, and the anterior/posterior spinal arteries and veins
What is the Lumbar cistern?
- From L2 to S2 vertebral level
- Lumbar puncture (site to take sample of CSF)
*Lumbar spinal puncture (spinal tap) is performed with the patient leaning forward or lying on the side with the back flexed
*Flexion of the vertebral column facilitates insertion of the needle by spreading the laminae and spinous processes
apart, stretching the ligament flava
*The needle is inserted in the midline between the spinous processes of the L3 and L4 (or the
L4 and L5) vertebrae
*Lumbar tap NEVER above the 3rd Lumber vertebrae
Where does the Spinal Cord extend from?
- Extends from the Foramen magnum to L1/L2 IV disc (medullary cone)
* Lumbar tap NEVER above the 3rd Lumber vertebrae
What are the 2 parts that the Spinal Cord expands?
- Cervical enlargement (C4 to T1 spinal cord segments)
2. Lumbar enlargement (T12 to L4 spinal cord segments)
What are the 2 substances in a Spinal Cord?
- White Substance
2. Gray substance
What is Gray Substance?
- Grey substance creates two columns that are joined together by grey matter (creating a H-like structure)
- Contains Neuronal Body that have in intercalated neurons in the Posterior Horn
- The Anterior Horn contains somatic motor (efferent) neurons
What is Visceral Motor (efferent) neurons?
- Part of the Gray substance
- Can be sympathetic (Lateral horn: T1 to L2) or parasympathetic (Intermediate zone: S2 to S4)
- Sensory (afferent) can be somatic or visceral in the Dorsal Root Ganglia
*Visceral efferent (motor) fibers that stimulate smooth
(involuntary) muscle in the walls of blood vessels and organs,
modified cardiac muscle
