Nervous System Part 5 - Spinal and Cranial Nerves Flashcards
at each vertebral layer, we have ____ spinal nerves connecting to the spinal cord
two
how many pairs of spinal nerves are there?
31 pairs
- they can carry both sensory and motor information
each spinal nerve divides to form a ______________ rami and a _________ rami
posterior and anterior
what are anterior and posterior rami?
branches of spinal nerves
- take the sensory and motor signals and splits off so we can hit the different parts of the body
can both anterior and posterior rami carry both motor and sensory neurons within them?
yes
what is formed when the anterior rami group together in some parts of the body?
the plexi
what is a plexus?
a network of nerves that work together to innervate an area
what are the four plexi?
- cervical plexus
- brachial plexus
- lumbar plexus
- sacral plexus
where does the brachial plexus go?
the upper limb, a bit of thorax and runs through the armpit
which plexi go to the lower limb?
the lumbar and sacral plexi
where do the intercostal nerves run?
between the ribs at each level and innervate the muscles that are in between the ribs
where is the cervical plexus getting contributions from?
the anterior rami of C1 - C4 and a bit of C5
what does the cervical plexus innervate?
the skin and skeletal muscles of areas around the neck and the upper shoulders and chest
which nerve innervates the diaphram?
phrenic
what is the only nerve of the cervical plexus that does not stay in the neck and upper shoulder?
phrenic
- goes to the diaphragm (so it is very long)
where does the phrenic nerve come from?
the anterior rami of C3, C4 and C5
C3,4,5 keep the diaphragm alive
what are we talking about when we talk about nerve roots?
we are talking about the anterior rami that contributes to it
what is the only part of the cervical plexus that C5 contributes to?
phrenic nerve
where does the brachial plexus come from?
C5-C8 and T1
why do we have a C8 spinal nerve if we do not have a C8 vertebrae?
because the spinal nerves begin above C1 so C8 nerve ends up in between C7 and T1
what nerves are apart of the “M” of the brachial plexus?
- Musculocutaneous
- Median nerve
- Ulnar nerve
where does the musculocutaneous run from?
it runs along the anterior arm
what does the musculocutaneous nerve innervate?
your anterior arm muscles
where does the median nerve run?
down the anterior of your arm and forearm all the way into your hand
what does the median nerve innervate?
anterior forearm muscles
where does the ulnar nerve run?
stay fairly medial and is going to go around the posterior of the elbow joint
- runs medial to the olecranon process
- runs all the way down the medial posterior side of the forearm into to hand
what are you hitting when you hit your funny bone?
your ulnar nerve
what does the ulnar nerve innervate?
most of the hand
- intrinsic muscles
which nerve is behind/posterior the ‘M’ of the brachial plexus?
the radial nerve
where does the radial nerve run along?
the posterior of the arm
what does the radial nerve innervate?
the posterior arm and forearm muscles
why do the lumbar and sacral plexus have a bit of crossover?
because L4 is a nerve root to both
for the most part, which part of the lower limb does the lumbar plexus handle?
the anterior and medial aspects of the lower limb
for the most part, which part of the lower limbs does the sacral plexus handle?
the posterior aspects of the lower limb
why are the lumbar and sacral plexus often considered as one plexus (lumbarsacral plexus)?
because of the nerve root crossover
where is the lumbar plexus getting contributions from?
L1-L4
which plexus is the femoral nerve apart of?
the lumbar plexus
where does the femoral nerve run?
heads down anteriorly
what does the femoral nerve innervate?
the anterior thigh
where does the obturator nerve head towards?
the medial thigh
which plexus is the obturator apart of?
the lumbar plexus
what does the obturator nerve innervate?
all the adductor muscles of the medial thigh
what does the sacral plexus get contributions from?
L4-S4
what does the sacral plexus innervate?
the posterior of the lower limb
which plexus is the sciatic nerve a part of?
the sacral plexus
what is the biggest nerve in the body?
the sciatic nerve
where does the sciatic nerve run?
out the posterior of pelvic bones
- down the posterior thigh and leg
which nerve are we sitting on?
sciatic
where does the sciatic nerve come out from?
between the sacrum and the pelvic bones
what does the sciatic nerve innervate?
the posterior thigh muscles and the posterior leg
how many pairs of cranial nerves are there?
12
what are the 12 cranial nerves?
- olfactory nerve - S
- optic nerve - S
- oculomotor nerve - M
- trochlear nerve - M
- trigeminal nerve - B
- abducens nerve - M
- facial nerve - B
- vestibulocochlear nerve - S
- glossopharyngeal nerve - B
- vagus nerve - B
- (spinal) accessory nerve - M
- hypoglossal nerve - M
Name mnemonic: Oh oh oh they traveled and found Voldemort guarding very secret horcruxes
Function mnemonic: Some say marry money, but my brother says big brains mean more
