nursing and paramedicals undergraduate students

1. Anatomy
Of
spinal cord
Spinal nerves

2. Enteric Nervous System
• GIT( Gut)
Central Nervous System (CNS)
• Brain
• Spinal cord
Peripheral Nervous System (PNS)
• Cranial nerves (12 pairs)
• Spinal nerves (31 pairs)

3. Spinal cord
 Lower elongated part of
central nervous system
 Cylindrical in shape
 Extends from upper border
of the 1st cervical vertebrae
to the lower border of 1st
lumbar vertebrae L1 in adult
 L3 (newborn)

4.  Conus medullaris: tapered inferior
end.
 Cauda equina: origins of spinal
nerves extending inferiorly from
lumbosacral enlargement and conus
medullaris.
 Filum terminale
 median ligament of pia mater
extending from conus medularis to
first coccygeal vertebra.

5. Conus Medullaris
Cauda Equina
(horse’s tail)
L5
L4
L3
L2
Filum terminale

6.  Provide physical stability and shock absorption
 Three layers
◦ Dura mater
◦ Arachnoid mater
◦ Pia mater
 Spaces
◦ Epidural: anesthesia injected. Contains blood vessels, areolar
connective tissue and fat.
◦ Subdural: serous fluid
◦ Subarachnoid: CSF and blood vessels within web-like strands of
arachnoid tissue.

7. The adult spinal cord
terminates at the level of
the first lumbar vertebra
(L1)
Lumber puncture in
adult is done in
between L3-L4.

8. 8
 White matter = myelinated processes (white in
color)
 Gray matter = nerve cell bodies, dendrites, axon
terminals, bundles of unmyelinated axons and
neuroglia (gray color)

9.  H-shaped pillar with anterior &
posterior gray horns
 United by gray commissure
containing the central canal
 Lateral gray column (horn)
present in thoracic & upper
lumbar segments
 Amount of gray matter related
to the amount of muscle
innervated
 Consists of nerve cells,
neuroglia, blood vessels

10. Cervical Thoracic
Lumbar Sacral
Regional Differences
Cervical
enlargement
Lumbar
enlargement
Lateral
horn

11. • fiber tracts for transmission of information
• Ascending (sensory) tracts
• Descending (motor) tracts
White Matter
Posterior funiculus
Lateral funiculus
Anterior funiculus

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16. The basic classifications of a spinal cord injury are:
Tetraplegia (Quadriplegia)
Injury to the spinal cord in the cervical region with associated loss of
muscle strength in all four extremities.
Paraplegia :- Injury to the spinal cord in the thoracic, lumbar, or
sacral segments, including the cauda equina and conus medullaris,
are associated with loss of muscle strength in the lower extremities.

17. Vessels of the spinal cord
 Anterior spinal vessels
 Posterior spinal vessels
 Radicular vessels

18. Anterior spinal artery (Medial Medullary syndrome)
 Supply anterior
⅔ of spinal cord
Posterior spinal arterie
Arise from vertebral artery or
(PICA)
Supply posterior ⅓ of spinal cord

20. 8 pairs of cervical spinal
nerves; *C1-C8
12 pairs of thoracic spinal
nerves; T1-T12
5 pairs of lumbar spinal
nerves; L1-L5
5 pairs of sacral spinal
nerves; S1-S5
1 pair of coccygeal spinal
nerves; C0

21.  Thirty-one pairs of spinal nerves
 First pair exit vertebral column between skull and
atlas.
 Last four pair exit via the sacral foramina
 Others exit through inter-vertebral foramina
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22.  Spinal nerves indicated by capital letter and number
 Dermatomal map: skin area supplied with sensory
innervation by spinal nerves
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24.  Complex network of ventral primary divisions
of spinal nerves
 Four large plexuses
 Ventral rami of C1-C4= cervical plexus
 Ventral rami of C5-T1= brachial plexus
 Ventral rami of L1-L4= lumbar plexus
 Ventral rami of L4-S4= sacral plexus

25.  S4-S5; coccygeal nerve
 Muscles of pelvic floor
 Sensory information from skin over coccyx

26.  C1-C4
 Innervates superficial neck structures, skin of neck,
posterior portion of head
 Ansa cervicalis: loop between C2 and C3
 Phrenic nerve
◦ From C3-C5 (cervical and brachial plexuses)
◦ Innervate diaphragm
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28.  Nerve plexus of C5- C8 and T1
 Five ventral rami form three trunks that separate
into six divisions then form cords that give rise to:
 Branches/nerves
◦ Axillary
◦ Radial
◦ Musculocutaneous
◦ Ulnar
◦ Median
◦ Smaller nerves such as pectoral, long thoracic,
thoracodorsal, subscapular, suprascapular
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29.  Laterally rotate
arm-teres minor
 Abducts arm-
deltoid
 Skin: inferior lateral
shoulder
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30.  Movements at
elbow and wrist,
thumb movements
 Skin- posterior
surface of arm and
forearm, lateral
2/3 of dorsum of
hand
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31.  Movements at
shoulder, elbow
and wrist.
 Skin- lateral
surface of forearm
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32.  Movements at
wrist, fingers,
hand
 Skin- medial 1/3
of hand, little
finger, and medial
½ of ring finger
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33.  Movement of hand,
wrist, fingers,
thumb
 Skin- Lateral 2/3
palm, thumb, index
and middle fingers;
lateral ½ of ring
finger and dorsal
tips of same fingers
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35.  Lumbar plexus: ventral
rami of L1-L4
 Sacral plexus: ventral rami
of L4-S4
 Usually considered
together because of their
close relationship
 Four major nerves exit and
enter lower limb
◦ Obturator
◦ Femoral
◦ Tibial
◦ Common fibular (peroneal)
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36.  Adduction of the
thigh and knee
 Skin- superior
middle side of
thigh
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37.  Movements of hip
and knee:
iliopsoas,
sartorius,
quadriceps
femoris
 Skin- anterior and
lateral thigh;
medial leg and
foot
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38.  The two nerves
together referred to
as the sciatic
(ischiadic) nerve
 Tibial
◦ Movement of hip, knee,
foot, toes
◦ Skin: none
◦ Branches are medial
and lateral plantar
nerves, sural nerve
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39.  Common fibular
◦ Anterior and lateral
muscles of the leg
and foot
◦ Skin distribution:
lateral and anterior
leg and dorsum of
the foot.
◦ Branches are deep
and superficial fibular
(peroneal) nerves
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40.  General disorders
◦ Anesthesia: loss of sensation
 Hyperesthesia: increased sensitivity to pain, pressure,
light
 Paresthesia: tingling, prickling, burning
 Neuralgia: nerve inflammation causing stabbing pain
 Sciatica: pain radiating down back of thigh and leg
 Infections
◦ Herpes: skin lesions
◦ Shingles or herpes zoster: adult disease of
chickenpox
◦ Poliomyelitis: infantile paralysis
◦ Anesthetic leprosy: bacterial infection of peripheral
nerves
 Genetic and autoimmune disorders
◦ Myasthenia gravis: results in fatigue and muscular
weakness due to inadequate ACh receptors

41. THANK YOU