PNS Neurons Flashcards
4 types of tissues that make up the body
muscle, epithelia, connective tissue, nervous tissue
What are components of the PNS
cranial nerves
spinal nerves
elements of ANS
(everything that is not the brain and CNS)
2 benefits of neurons
communicate over long distance
form networks that enable computations (complex processes)
Anatomy of neuron (3)
cell body (soma) where nucleus is
2 processes
-axon: send info away from cell body
-dendrite: receive info
one role of glial cells
provide electrical insulation (myelin sheath)
Brain -
inside: __ matter
outside: __ matter
white (axon)
grey
Color -
cell bodies:
axons:
cell bodies: grey matter
axons: white matter
Spinal cord -
inside: __ matter
outside: __ matter
grey
white (axon)
___ cover the CNS and consists of 3 layers (outer to inner):
meninges;
dura, arachnoid, pia mater
Arachinoid trabeculae connect layers __ and __ inside the ___ space, filled with ___.
arachnoid, pia;
subarachnoid space;
cerebral spinal fluid (CSF)
Benefits of CSF (3)
- reduce weight of brain
- shock absorber
- distribute hormones, nutrients; removes waste from CNS
CSF is produced in ___ and drained into the ___ system
choroid plexus, venous
The structure through which CSF is drained into the venous system
arachnoid villi (arachnoid granulations)
arachnoid villi (arachnoid granulations) are extensions of the __ __ __
dural venous sinuses
dural venous sinuses (formed by __ mater) carry ___ blood away from CNS
dura, deoxygenated
order of layers from outside to inside: __ mater, arachnoid mater, CSF, __ mater
dura, pia
somatic neurons innervate __ __
visceral neurons innervate __
body wall (skeletal muscle, skin)
viscera (organs, involuntary muscles, blood vessels)
somatosensory aka __
direction of signal
somatic afferent
body wall –> CNS
arrive at CNS
somatomotor aka __
direction of signal
somatic efferent
CNS –> body wall
outward, exit CNS
motor = \_\_ sensory = \_\_
efferent
afferent
SE neurons are located in __ horn of spinal cord
ventral
SA: __ horn
dorsal
DRG carries ___ neuron cell bodies
SA
visceral motor neurons (__) are part of the __ nervous system
VE neurons, autonomic
Direction of VA neurons (__)
visceral sensory neurons; organs –> CNS
VA neurons moving towards/away from CNS carry the following information:
towards; stomach distension, pain, BP, pH, [glc], etc.
spinal nerves are combination of __ and __ nerve fibers
sensory, motor
__ branch out from roots and carry mix of both SA and SE neurons
rami
There are __ pairs of spinal nerves
numbers for cervical, thoracic, lumbar, sacral, coccygeal
31
8,12,5,5,1
There are __ cervical spinal nerves and __ cervical vertebrae
8, 7
Define dermatome
cutaneous sensory innervation that corresponds to the organization of the spinal nerves
How many spinal nerves are present in each section: Cervical Thoracic Lumbar Sacral Coccygeal
Cervical - 8 (7 vertebrae) Thoracic - 12 Lumbar - 5 Sacral - 5 Coccygeal - 1 (between coccygeal pair)
The “end” of the spinal cord is __ __, terminating at level __-__.
conus medullaris; L1-L2
Nerves that need to reach target below L2 are collectively known as __ __
cauda equina (horse’s tail)
What helps anchor the spinal cord in place within the vertebral canal? What is it made of?
filum terminale; pia mater
compression of SE causes:
compression of SA causes:
(due to decreased conduction)
SE: muscle weakness, flaccid paralysis
SA: numbness, tingling, pain
