57 terms

Nervous System

STUDY
PLAY
central nervous system (CNS)
the _ consists of the brain and spinal stem
peripheral nervous system (PNS)
the _ consists of all neurons, nerves, glia cells, and sensory receptors outside the CNS
sensory (afferent) system
conducts one way sensory impulses from the peripheral body parts to CNS
motor (efferent) division
conducts one way motor commands from the CNS to the effectors (anything that will respond to the CNS)
somatic nervous system
conducts one way conscious motor commands to the skeletal muscles
-branch of the motor division
autonomic nervous system
conducts one way subconscious motor commands to cardiac, smooth muscles, and glands
-branch of motor division
sympathetic nervous system
prepares the body for stress: the fight of flight response
-branch of autonomic nervous system
parasympathetic nervous system
returns the body back to pro-stress normal conditions
-branch of autonomic nervous system
afferent (sensory) function
responds to stimulation -conducts sensory impulses to CNS -function of the nervous system
intergrative function
intergrates incoming sensory information with exsisting memory -creates sensation, perception, makes a conscious or subconscious command -funciton of the nervous system
efferent (motor) function
conducts motor commands via the 31 pairs of the spinal nerves and 12 pairs of cranial nerves to the effectors
sensation
the arrival of the stimulus in the CNS
perception
awareness of the sensation
soma
body of a neuron and contain nissl bodies
nissl bodies
causes a gray, granular appearance and it causes gray matter
neurofilaments and neurotubules
_ and _ give the framework and structure for a soma
perikaryon
the cytoplasm of a soma is called _
dendrites
cytoplasmic processes of fibers and conduct nerve impulses TO the soma
axons
cytoplasmic processes or fibers that conduct nerve impulses AWAY from the soma
axonal hillock
where the axon emerges away from the soma
axolemma
the cell membrane around the axon
axoplasm
cytoplasm within the axon
axoplasmic transport
the axoplasm contains a network of neurotubules called the _. It moves materials between the soma and the synaptic knob
kinesins and dyneins
the axoplasmic transport uses chronical molecules called _ and _ to quickly transport materials
anterograde transport
uses dyneins (soma -> synaptic knob)
retrograde transport
uses kinesins (toward cell body) *maybe a disadvantage for rabies
axon collateral
off the side of the axon
telodendria
end in synaptic knob, the terminal fine branches
myelin
white fatty substance that increases the rate of nerve impulse (cholesteral)
type A axons (fibers)
myelinated and fastest conducting type of axon (300 mph)
type B axons
myelinated and slower conducting type of axon (40 mph)
type C axons
unmyelinated and slowest conducting type of axon (2-3 mph)
sensory (afferent) neurons
conduct impulses from peripheral body parts from CNS - have receptors on dendrites or connect to sensory receptors within special tissues and organs -a classified neuron by function
somatic sensory neurons
monitor external environment (skin, sight, sound)
visceral sensory neurons
neuron that monitors the internal environment
exteroceptor
a type of receptor on the dendrite or connected to the neuron that monitors external environment
proprioceptor
a type of receptor on the dendrite or connected to the neuron that is found within joints and muscles -monitors position and movement
interoceptor
a type of receptor on the dendrite or connected to the neuron that monitors internal environment (sense of pain, taste, deep pressure)
association neuron (interneuron)
in CNS -connect CNS neurons to PNS -connect part of the PNS to PNS -a classified neuron by function
motor (efferent) neuron
neuron that conducts motor impulses from the CNS to the effectors
effectors
muslces or glands
multipolar neuron
neuron that has many dendrites to one neuron -most are this kind
bipolar neuron
it has their axon and dendrite emerge from opposite sides of the soma -rare (in nose, eyes, and ears)
unipolar neuron
type of neuron my structure that has a single point where the axon and dendrite emerge
ganglia
somas are grouped together and called _
anaxonic neuron
type of neuron that does not have a distinguishable axon -farely rare -not a known function
astrocytes
provide structure and framework for the CNS -largest of the glia cell -form scar tissue -control and monitor the Blood Brain Barrier (CNS Glia Cell)
microglial cells
smallest -phagocytic macrophages -sanitation/eat debris (CNS Glia Cell)
ependymal cells
form the lining of the ventricles and the central canal of the spinal cord -monitors and circulates CSF..cerebral spinal fluid (CNS Glia Cell)
oligodendrocyte
form myelin around the axon (CNS Glia Cell)
schwann cell
forms myelin around axons -can only for myelin on one axon -can insulate the axon (PNS Glia Cell)
neurilemma
the outermost layer of a schwann cell
wallerian degeneration
when a schwann cell repairs severed axons
diptheria
causes the myelin in the brain to demyelinate
multiple sclerosis
myelin loss around the muscles
heavy metal poisoning
lead, mercury, or cadmium contaminating the body
satellite cell
wraps around the ganglia -protects it (PNS Glia Cell)