unit 7 Flashcards
cns
-brain and spinal cord
-command center
-closed system
-interprets incoming info and issues outgoing instructions
pns
-cranial and spinal nerves (anything outside of cns)
-open system with fewer supporting cells
-communication lines; carries impulses
sensory division
afferent; nerve fibers carrying info to cns; somatic and visceral organs
motor division
efferent; nerve fibers carrying info away from cns;
somatic
skeletal muscles, skin, and joints
voluntary
just skeletal muscles
autonomic
involuntary; cardiac and smooth muscle glands; into parasympathetic and sympathetic
neurons
actual nerve cell that sends and receives messages
neuroglia
supporting cells; never lose ability to divide; support, insulate, and protect neuron; do not conduct nerve signals
general structure of neuron
cell body and processes
cell body
nucleus (decision maker-control center)
processes
bring in or send away messages; fibers that extend away from cell body (dendrites and axon)
myelin sheath
-white fatty protein covering axon
-schwann cells wrap like jelly roll
-protect and insulate nerve fibers and speed up nerve transmission
gray matter
unmyelinated fibers and cell bodies
white matter
myelinated fibers (tracts) - axons; corpus callosum - association fiber tracts and projection fiber tracts
interneurons
connect sensory and motor neurons
types of general sensory receptors
multipolar, bipolar, unipolar
multipolar neurons
extensions; motor and interneurons; most common
bipolar neurons
one axon and one dendrite; sense organs; rare
unipolar neurons
sensory in pns ganglia; impulses both away and toward
reflex arc
reflexes occur over neural pathways
reflexes
involuntary; somatic and autonomic
2 neuron reflex arc
patella and knee reflex
3 neuron reflex arc
(5 elements of reflex arc) receptor, sensory neuron, interneuron, motor neuron, and effector; flexor (withdrawal) reflex
cerebral hemispheres
large halves or brain; gyrus, sulcus, and longitudinal fissure; cortex (gray matter), white matter, basal nuclei (deep pockets of gray matter)
diencephalon
thalamus, hypothalamus, and epithalamus
brain stem
midbrain, pons, medulla oblongata
cerebellum
controls balance and coordination; gray and white matter
dura mater
outermost layer; 2 layers
arachnoid
middle layer; subarachnoid space for cerebrospinal fluid
pia mater
internal most layer
cerebrospinal fluid
continually made by choroid plexuses; special capillaries
blood-brain barrier
allows water, glucose, and amino acids to pass through capillary walls
concussion
slight brain injury; little permanent brain damage
brain contusion (skull smashed)
marked nervous tissue destruction occurs; coma
intracranial hemorrhage
death; direct blood contact
cerebral edema
death; swelling in or around brain
CVA
stroke; blocked brain circulation and kills tissue
TIA
temporary restricted blood flow; numbness
alzheimers
dementia
parkinsons
basal nuclei problem; posture and movement
huntingtons
genetic disease - basal nuclei - cerebral cortex; wild movements and spastic; lack of focus, fatigue, and irritability