2. Spinal Cord
Major Features:
Medullary Cone
Terminal end at L1 and attaches to the coccyx
Filum Terminale or Terminal filum
Pia mater that attaches to the coccyx
Cauda Equina
The continuation of the spinal cord as extension of parallel nerve fibers in the
lumbar and sacral region
Resembles a horse’s tail
Cervical Enlargement
Occurs at C3-T2
Lumbar Enlargement
Occurs at T7-T11
Bulge in the spinal cord and has increasing out put to the upper and lower
extremities
3.
4. Cross Section of Spinal Cord
Gray Matter
“H” appearance or a butterfly
Middle of the spinal cord
Gray Horns
Posterior: Narrow,, receive sensory
Anterior: Rounded, send motor
Lateral: Neurons of sympathetic division
Gray Commissure
Connection between the gray matter
Central Canal
Middle of the commissure
White Matter
Peripheral
Opposite of brain
Posterior Median Sulcus
Smaller depression
Anterior Median Fissure
Deeper depression
5. White Matter
Can be divided into tracts
Tracts
Takes sensory info to the brain (CNS)
Parallel nerve fibers in the CNS whereas, nerves are parallel fibers in the PNS
Ascending Tracts
Takes sensory information
Descending Tracts
Receives motor information
6. Meninges
The spinal cord and brain are both
covered by Meninges
Dura Mater: Outer covering
Epidural Space: Between the dura and
vertebra
Arachnoid Mater: Deep to the Dura
Mater
Pia Mater: Deep to the Arachnoid
Subarachnoid Space: Between the pia
and Arachnoid
CSF is found here
7. Spinal Nerves
31 Pairs of Spinal Nerves
Pass through the intervertebral
foramina
8 Pairs of Cervical Nerves
12 Pairs of Thoracic Nerves
5 Pairs of Lumbar Nerves
5 Sacral Pairs
1 Pair of Coccygeal Nerves
8. Spinal Cord- Posterior
Dorsal (Posterior) Root
Union of two roots that attach to the spinal cord
and forms the spinal nerves
Takes Sensory information to the spinal cord
Dorsal Root Ganglion
Between the spinal nerves and the dorsal root
Cell bodies of specific nerves are found here
Posterior Division or Dorsal Ramus
Superficial to the intervertebral foramen
Spinal nerves divides
Takes sensory & motor fibers to the back
Dorsal root ganglion
9. Spinal Cord- Anterior
Ventral (Anterior) root
Adjacent to the dorsal root
Takes motor information from the spinal
cord to the muscles
Anterior Division or Ventral Ramus
Takes sensory and motor fibers to the
other parts of the body
10. Plexus Nerves
Made up of network of nerve fibers
Spinal Roots Trunks Anterior/Posterior
Divisions Cords Nerves
There are 4 plexuses:
Cervical
C1-C5
Brachial
C5-T1
Lumbar
L1-L4
Sacral
L4-S4
11.
12. Cervical & Brachial Plexus
Upper spinal nerves of the neck
Phrenic Nerve
Runs to the diaphragm
Innervate muscles and skin of the neck
and skin of the ear
Axillary, Median, Radial & Ulnar Nerves
Innervate muscles that flex forearm
13. Lumbar & Sacral
Plexus
Takes Sensory information and
motor information to the lower
limb
Lumbar
Obturator & femoral nerves
Anterior thigh innervations
Sacral
Tibial, Common Fibular, &
Sciatic Nerve
Innervate posterior thigh, leg &
foot
14. Know For The Lab Exam
Major structures of the spinal cord
Cross Section & Longitudinal
Meninges
All the different layers & the spaces
Spinal Nerves
Posterior & Anterior section of Spinal Cord
