1. Spinal Cord, Spinal Nerves, Plexuses

2. Spinal Nerves
There are 31 pairs of spinal nerves
They each contain thousands of nerve fibers
They arise from the spinal cord and supply all parts of the body except the head and some areas of the neck
The nerves are named according to their point of issue from the spinal cord
Spinal nerves are named as followed:
C1 C7 for the vertebrae below it
C8 C0 for the vertebrae above it
3. Spinal Nerves
4. Cervical Spinal Nerves (C1 C8)
C1 C8
5. Thoracic Spinal Nerves (T1 T12)
T1- T12
6. Lumbar Spinal Nerves (L1- L5)
L1 L5
7. Sacral Spinal Nerves (S1- S5)
S1 S5
8. Coccygeal Nerve C0
C0
9. CaudaEquina
Is the collective nerve roots at the end of the spinal cord.
Looks like a horses tail
The spinal cord ends between L1 and L2and the roots of L3 C0 make up the Cauda Equina
10. ConusMedullaris
Conus Medullaris
is the tapered cone shaped portion at the inferior end of the spinal cord
Filum Terminale
Connects the conus medullaris to the upper coccyx.
Is a fibrous extension of the conus covered in pia mater.
It anchors the spinal cord and prevents damage from movement
11. Lumbar Puncture
Is the insertion of a sterile needle into the sub arachnoid space, usually between the 3rd and 4th lumbar vertebrae.
The procedure is used to detect increased intercranial pressure or the presence of blood in the CSF
12. Lumbar Puncture
The insertion of the needle occurs at this point because there is no spinal cord present after L3 and therefore there is little chance of spinal cord damage but CSF is still present in the sub arachnoid space.
13. Plexuses
A plexus is an interlacing group of nerve fibers which occur in the cervical, brachial, lumbar and sacral regions
The plexuses primarily serve the limbs
This means that each muscle in a limb is supplied with impulses from more then one spinal nerve
14. CervicalPlexus
C1 C4
Formed by the first four cervical nerves
Most branches are cutaneous nerves
Others innervate muscles of the anterior neck
Cervical
Plexus
15. CervicalPlexus
C3, C4 and C5 give rise to the phrenic nerve which innervates the diaphragm.
16. Brachial Plexus
C5- T1
formed by the last four cervical and the 1st Thoracic nerve.
It is situated in the neck and partially in the upper arm (axillary region)
It gives rise to virtually all the nerves that innervate the arm
Brachial
Plexus
17. Brachial Plexus
18. Brachial Plexus
19. Nerves from the Brachial Plexus
Axillary Nerve
Innervates the deltoid muscle
Musculocutaneous Nerve
Innervates the biceps brachii
Musculocutaneous nerve
Axillary
Nerve
20. Nerves from the Brachial Plexus
Radial Nerve
Innervates the triceps and the extensors
Ulnar Nerve
Innervates the flexor carpi ulnaris
Radial Nerve
Ulnar Nerve
21. Nerves from the Brachial Plexus
Median Nerve
Innervates the flexors of the palm and forearm
Median Nerve
22. Carpal Tunnel Syndrome
Occurs when the median nerve, which runs from the forearm to the hand becomes compressed or damaged.
Some symptoms include :
Pain, weakness, numbness, tingling in the hand
The nerve is squeezed against the bones and ligaments
Treatment
Most commonly treated by cutting the transverse carpal ligament increase the diameter of the carpal tunnel
23. Lumbar Plexus
T12 L4
Arises from the last thoracic (Sub-costal nerve) and the first 4 lumbar nerves
Gives rise to nerves which innervate the flexors and the adductors of the leg
Lumbar Plexus
24. Lumbar Plexus
25. Nerves from the Lumbar Plexus
Obturator
innervates the adductors of the thigh
Femoral
Innervates the quadriceps
Obturator
Nerve
Femoral Nerve
26. Sacral Plexus
L4 S5
Comprised of the last two lumbar and all the sacral nerves
Innervates the buttocks and the lower limbs
Sacral Plexus
27. Sacral Plexus
28. Nerves from the Sacral Plexus
Sciatic Nerve
The largest branch of the sacral plexus
Innervates the hamstrings
Appears from under the piriformis muscle
Piriformis Muscle
Sciatic Nerve
29. Nerves from the Sacral Plexus
Tibial Nerve
Innervates the gastrocnemius and the soleus
Peroneal Nerve
Innervates the tibialis anterior and other dorsiflexors
Tibial Nerve
Peroneal
Nerve
30. Nervous Injuries
Below are the names of some injuries to specific nerves.The name of the injured nerve is beside them.
Whiplash C4 / C5 or C5 / C6
Crutch Paralysis Radial Nerve
Wrist drop Radial Nerve
Carpal Tunnel Syndrome Median Nerve
Sciatica Sciatic Nerve
31. Dermatomes
DEFN the area of skin innervated by the cutaneous branch of a spinal nerve.
Occurs in every spinal nerve except C1
Dermatomes help physicians determine which nerves are damaged and localize the injured region of the spinal cord
32. Deramtomes