The Central Nervous System Flashcards
(35 cards)
Cannon’s Postulates
- nervous regulation of internal environment
- tonic control
- antagonistic control (insulin and glucagon)
- one chemical signal can have different effects in different tissues (epinephrine)
CNS
brain and spinal cord
PNS
all nerves, connecting to the CNS, cranial, and spinal
gray matter
unmyelinated nerve cell bodies
dendrites
axon terminals
white matter
myelinated axons
contains very few cell bodies
the brain is encased in bony skull or
cranium
spinal cord runs through
vertebral column
meninges
lies between bones and tissues
meningeal layers
of the brain cushion and protect delicate neural tissue
spinal cord is protected by
vertebrae and meninges
connective tissue layers that surround the spinal cord
dura mater
arachnoid membrane
pia mater
structure and formation of the spinal nerve: roots
2 bundles
dorsal root: sensory
ventral root: motor
processing of sensory input and motor output
gray matter
dorsal gray horns
ventral and lateral gray horns
dorsal gray horns
process sensory information
dorsal gray horns
process sensory information
ventral and lateral gray horns
send out motor information
spinal cord white matter is divided into 3 sections
dorsal white columns
ventral white columns
lateral white columns
each section of the spinal cord white matter contains bundles of axons called
tracts
-ascending tracts: send signals toward the brain
-descending tracts: send signals away from brain
spinal cord function
processing of sensory and motor information
blood-brain barrier
astrocyte foot processes
tight junction
the astrocyte foot processes
secrete paracrines that promote tight junction information
tight junction
prevents solute movement between endothelial cells
cerebral spinal fluid (CSF)
- clear and colorless
- protects from chemical and physical injury
- continuously circulates through various openings in the brain and subarachnoid space
- produced by choroid plexus
2 metabolic needs of neural tissue are
oxygen
glucose