Spinal Nerves Flashcards
Spinal nerves
communication with the CNS by way of the spinal cord
how many pairs of spinal nerves are there?
31
Breakdown of the pairs of spinal nerves
8 pair CERVICAL NERVES - C1-C8
12 pair THORACIC NERVES T1-T12
5 pair LUMBAR NERVES - L`-L5
5 pair SACRAL NERVES - S1-S5
1 pair COCCYGEAL NERVES - Co1
CAUDA EQUINA
Nerves in the lumbar, sacral and coccygeal region travel through the vertebral canal below the end of the spinal cord as the CAUDA EQUINA before emerging out of the vertebral column.
Three protective coverings of connective tissue surrounding spinal nerves
epineurium
perineurium
endoneurium
epineurium
fuses with the dura of the spinal cord as it passes through the intervertebral foramina and surrounds the entire nerve.
perineurium
surrounds groups of axons known as fascicles.
endoneurium
surrounds individual axons that make up the spinal nerve.
Shortly after exiting the intervertebral foramen, spinal nerves divide into small branches called
Rami
The posterior (dorsal) ramus supplies the skin and deep muscles of the posterior trunk.
Axons from anterior rami of all spinal nerves except T2-T12 form inter-branching networks known as
plexuses (plexi).
Individual nerves then emerge from each plexus.
Be able to ID various plexi from a picture or model*
p 86 coloring book
Cervical Plexus
is responsible for many nerves of the head, neck and part of the shoulders.
Brachial plexus
responsible for nerves of the shoulder and upper limb.
Thoracic nerves
do not form plexi but serve most of the muscles and skin of the torso. Branches of these nerves become intercostal nerves.
Lumbar plexus
takes care of nerves of the anterior thigh, some abdominal wall and the external genitals.
sacral plexus
is responsible for the gluteal region, the perineum and most of the lower limb.
The cervical plexus supplies the skin and muscles of the….
A notable nerve emerging from this plexus is the _____ _____, which supplies motor impulses to the diaphragm.
head, neck, upper shoulders and chest
phrenic nerve
All spinal nerves are
mixed nerves - both sensory and motor
The brachial plexus is responsible for supplying…
Key nerves emerging from the brachial plexus include the
the upper limb and shoulder.
axillary nerve
musculocutaneous nerve
radial nerve
median nerve
ulnar nerve.
The lumbar plexus is responsible for the
anterolateral abdominal wall, external genitals and much of the anterior and medial thigh.
nerves emerging from the lumbar plexus include
the femoral nerve and the obturator nerve.
the sacral plexus supplies
the buttocks, perineum, the posterior thigh and most of the leg
The sciatic nerve emerges out of the _____ ____, and then divides into…
sacral plexus
the tibial nerve and common fibular (common peroneal) nerve.
The common fibular nerve divides into
a superficial and deep fibular (peroneal) nerve.
Dermatomes
regions of skin innervated by the sensory portion of a nerve.
Most dermatomes are related to spinal nerves, though the regions of the face supplied by the sensory portion of the trigeminal nerve (cranial nerve V) may be included as is done on this view.
