nervous system ch12 Flashcards
axon
fiber carries impulses along the nerve cell
cell body
contains nucleus, -soma, maintains life of neuron
ganglion
collection of nerve cell bodies
dendrites
branching structures that receive impulses or stimulus, first part
myelin sheath
fatty tissue around axon, protects and insulates axon
nodes of ranvier
gaps
synapse
space between neurons impulse passes, neurotransmitter
terminal end fibers
distal portion of neuron impulse leaves
acetylcholine
dream sleep and muscles to contract
dopamine
firing of nerve cells helps relax
endorphins
reducing pain for pleasure natural morphine
epinephrine
hormone acts as a neurotransmitter to increase heart rate and blood pressure
norepinephrine
causes vasoconstriction, increase heart rate and BP, noradrenaline
serotonin
relaxation, stress and behavioral disorders when decreased
astroglial cells
astrocytes, transport electrolytes and water between capillaries and neurons help form BBB
microglial cells
phagocytic cells which protect nervous system from infection
oligodendroglial cells
cells form the myelin around axon
ependymal cells
cells lines ventricles of the brain and surround the spinal cord, produce cerebrospinal fluid
schwann cells
dual action cells form myelin and acts as phagocytes against foreign organisms
neuron
individual nerve cell, basic unit
nerve
one or more bundles of impulse carrying fiber
plexus
network of nerves
function of nervous system
carries messages in the body, controls and coordinates activity, voluntary and involuntary
types
sensory, associative, motor
sensory
afferent
associative
connecting
motor
efferent
receptors
parts of NS receive external stimuli
nonreceptive
pain receptors
proproreceptor
special orientation receptors
stimulus
something that excites or activates
reflex
automatic involuntary response to a stimulus
neuroglial cells
supporting
myelinated
white matter
meninx, meninges
3 layers covering of brain and spinal cord, protects and nourishes
cerebral spinal fluid
CSF nourishes, cools, cushions CNS produced by ventricles of brain
dura mater
tough outermost layer of meninges, blood can enter brain through this layer
arachnoid membrane
middle layer of meninges, arachnoid mater
pia mater
innermost delicate layer of meninges adheres to brain and spinal cord, soft
epidural space
space above the dura matter
subdural space
space below the dura mater
subarachnoid space
space below the subarachnoid membrane where cerebrospinal fluid can be found
central nervous system
CNS brain and spinal cord
peripheral nervous system
PNS, cranial nerves, spinal nerves, autonomic nervous system
cranial nerves
attached to brain pass through skull to structures in the head and neck
spinal nerves
carry nervous impulses between spinal cord and the rest of the body
I. olfactory
smell
II. optic
vision
III. oculomotor
movement of eyes
IV. trochlear
movement of eyes
V. trigeminal
three branches: ophthalmic, maxillary, mandibular
VI. abducens
movement of eyes
VII. facial
movement of face, taste
VIII. vestibulocochlear
hearing and balance
IX. glossopharyngeal
tongue taste throat movement
X. vagus
throat voice box chest movement abdominal sensations
XI. accessory
neck and shoulder movement also know ans spinal accessory nerve
XII. hypoglossal
tongue movement
autonomic nervous system
ANS nerves that control involuntary functions of muscles glands and viscera
blood brain barrier
BBB, capillaries that allow certain substances to the brain while keeping other substances out
cerebral cortex
outermost section of cerebrum
cerebrum
larges part of the brain responsible for voluntary , speech, vision, hearing, thought, memory, taste
cerebellum
second largest part of the brain, balance and coordination
conscious
awake alert aware responsive
medulla oblongata
stem like of the brain-stem connecting brain to spinal cord essential life function, breathing heart and BP
neurotransmitter
chemical messenger released from a neuron to stimulate or inhibit another nerve or target cell
parasympathetic nervous system
portion of autonomic nervous system normal body functions, HR and RR
peripheral nervous system
portion of nervous system consisting of cranial nerves, spinal nerves and autonomic nervous system
ventricles of the brain
spaces in the interbrain contains CSF
cerebrum
largest part of brain
gyri
folds
sulei
groove
brainstem
connects brain to spinal cord
midbrain
visual and auditory reflexes posture muscle control
interbrain
pituitary hypothalamus thalamus
pons
bridge allows nerve from cerebrum to talk to cerebellum
cauda equina
looks like a horse tail
levels of consciousness
BAR, conscious, disoriented, lethargy, obtunded, stupor comatose
catalepsy
muscle rigidity and trance like state
aneurysm
localized widening of a blood vessel
ataxia
lack of coordination
concussion
violent shaking of the brain
contusion
a bruise without breaking the skin
computed tomography
CT, cat scan, radiographic imaging showing computerized cross section of brain and spinal cord
contraindication
any condition that renders a particular treatment undesireable
epilepsy
idiopathic brain disorder, seizures
lethargy
condition of drowsiness or indifference
magnetic resonance image
MRI, radiographic imaging showing 3D image of brain
myasthenia gravis
neuromuscular disorder characterized by weakness of skeletal muscles
narcolepsy
condition of sudden uncontrollable sleep episodes
paralysis
loss of motor functions, palsy
positron emission tomography
PET, radiographic imaging, injection of dye
seizure
sudden involuntary contractions of voluntary muscles, also called convulsions, grand mal or tonic clonic
spasticity
increased muscle tone
stupor
partial unconsciousness and decreased response to stimuli
syncope
fainting
tremor
repetitive twitching of skeletal muscles
vestibular disease
idiopathic neurological disorder characterized by head tilt, circling and rapid back and forth movement of eyes