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