Spinal Cord Cross-Section
gray matter
Where does the spinal cord end?
conus medullaris
name the 3 meningeal layers from superficial to deep
dura, arachnoid, pia
what structure of the CNS are reflexes initiated and completed?
spinal cord
chemoreceptors
The dorsal roots are located ____ and the ventral roots are located ___?
posterior, anterior
The spinal cord is protected by what two things?
meninges and CSF
where are spinal taps performed in the vertebrae?
arachnoid space below L2
A _____ is an area of skin supplied by a single spinal nerve.
dermatome
What are the three main types of mechanoreceptors?
-proprioceptors, baroreceptors and tactile receptors
These are formed by the fusion of dorsal and ventral roots?
spinal nerves
The vertebral column is starts ___ and ends at ___.
The vertebral column is starts at the foramen magnum and ends at L1 and L2 vertebrae.
What is paresthesias?
Paresthesias is the feeling of tingling, numbness, pins & needles that is caused by damage to dorsal roots or sensory tracts.
polysynaptic and monosynaptic
Name and briefly explain the two classes of nociceptors?
they are pain receptors
Type A=fast pain thats localized (cuts)
Type C= slow pain thats more general (burning)
From the gray matter explain the difference between the ventral and dorsal roots?
ventral= motor neurons that exit the spinal cord/act as effectors (away from CNS to effector organs)
dorsal=bring sensory input to the CNS are affectors/afferent
Where is the CSF located?
subarachnoid space between the arachnoid and pia maters
first-order neurons do what?
Conducts impulses from cutaneous
receptors (skin) and proprioceptors (touch) to 2nd order neuron
the phrenic nerve originates from the ___ plexus and innervates the _____
cervical, diaphragm
What is a positive vs. negative babinski test?
test that strokes foot on the lateral side of the foot to test for injury to CNS
positive= fanning of toes, dorsiflexion (infants)
negative=plantar flexion, curling of toes
Explain the difference between 1st, 2nd, and 3rd order neurons.
1st- (skin)sensory neuron that conduct impulses from skin & proprioceptors to 2nd order neuron
2- (spinal cord)interneuron located in spinal cord that conducts impulse to thalamus or cerebellum
3- (brain)interneuron located in the thalamus that brings info to the somatosensory cortex
This is the fibrous extension of conus covered
with pia mater that functions to anchor spinal cord?
filum terminale
Define decussation
describes how nerve fibers cross from one side of the spinal cord to the other, so that brain can coordinate activities with the opposite side of the body
The cervical plexus is made up of _______ , the brachial plexus is _____, and the lumbar plexus is ______?
C1-C5, C5-T1, L1-L4
Name all the cranial nerves in order from 1-12 (including their correct corresponding numbers)!!!!!