Lecture 3 (The Nervous System) Flashcards
two branches of nervous system
CNS and PNS
divisions of CNS
brain and spinal cord
divisions of PNS
cranial nerves and spinal nerves
definition of nucleus in nervous system
many cell bodies (soma) together
where is the myelin in the spinal cord
on the outside
composition of white matter in spinal cord
axons, tracts
composition of grey matter in spinal cord
nuclei (cell bodies) and synapses
tract
collection of nerve cell processes in CNS
nerve
collection of nerve cell processes (axons/nerve fibres) OUTSIDE CNS
ganglion
nerve cell bodies (somas) outside CNS
track of afferent fibres
sensory axons toward CNS in dorsal root ganglion
track of efferent fibres
motor axons conducting away from CNS in ventral root
dermatome
skin segment related to a spinal nerve
what kind of nerves are pure (only one type)
roots of spinal nerves
what kind of nerves are mixed (afferent and efferent)
spinal nerves and their branches
two cortexes and what they control
sensory controls what goes in, motor controls what goes out
what is different about reflexes
do not come in through DRG, motor neuron in grey matter of SC is what reacts
inhibitory neuron
interneuron
ventral ramus
goes to limbs, innervates superficial back muscles to limbs and everything else
dorsal ramus
innervates deep back muscles and overlying skin
IVF has an opening for the
spinal nerve, it is bounded by bone
number of cervical vertebrae and nerves
7 vertebrae, 8 nerves
where are the nerves located
c1-c7 is above, c8 is below, T1 and the rest are below
where do the roots of the nerves come from
the original IVF of exit
where is the conus medullaris
end of spinal cord at L1/L2
what is the cauda equina made of
nervous tissue
what is the filum terminale made of
pia matter, not nervous tissue, just connective
covering of spinal cord
pia matter (tender mother) arachnoid matter (spider mother) dura matter (hard mother)
epidural space
outside the dura, use for anesthesia – have no pain but can still move
subarachnoid space
known as lumbar cistern, between arachnoid and pia. largest around the cauda equina – location for withdrawing CSF or spinal block anesthesia
the fascicle is surrounded by the
perineurium
the fasciculus is surrounded by the
endoneurium
a nerve trunk is surrounded by
epineurium
nerve trunk contains
fascicles which contain fasiculus which contain many neuronal axon/nerve fibers
