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nervous system:
Directs functions of body’s organs and systems Interprets external environmentDetermines reaction to change
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homeostasis:
In the short term, homeostasis is maintained by the nervous system In the longer term, homeostasis is maintained by endocrine system
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central nervous system (CNS):
brain and spinal cord
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peripheral nervous system (PNS):
everything else
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afferent peripheral system:
Sensory neurons – input to brain
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efferent peripheral system:
Somatic nervous system
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neuron: a nerve cell –
made up of 3 parts
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cell body:
the mass of the cell, with nucleus and support machinery
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dendrites:
receptive areas, i.e. inputs
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axon:
extension of cell body, i.e. output
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receptor:
detects environmental stimuli
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sensory:
receives impulse from receptor site
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internuncial:
transmit impulse for interpretation and processing
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motor:
reaction to the stimulus
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nerve impulses:
are transmitted along nerves much the same way that data is transmitted along an ethernet cable: electrically
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resting potential:
of a nerve cell fiber Negative charge on inside Positive charge on outside
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depolarization:
Na+ rush into cell
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repolarization:
K+ rush out to restore balance
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synapse:
the junction between an axon terminal branches close to next dendrites
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neurotransmitter:
acetylcholine most common- epinephrine, norepinephrine, serotonin, dopamine, endorphins
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white matter:
groups of myelinated axons forms nerve tracts in CNS
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gray matter:
nerve cell bodies and dendrites, unmyelinated axon bundles, cortex: gray matter on surface of brain
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the brain is protected by:
cranial bones, meninges, cerebrospinal fluid (CSF)
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brainstem:
controls breathing, heartbeat rates and reactions to auditory and visual stimuli
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diencephalon:
controls homeostasis
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cerebrum:
controls intellectual processes and emotions
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cerebellum:
maintains body posture and balance
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medulla oblongata:
has ascending and descending tracts, connect spinal cord with the brain, some tracts cross over in medulla
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pons varolii:
usually just called the pons, connects spinal cord with brain, connects parts of brain with each other, helps control breathing
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optic tracts:
the nerves from the eyeball
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thalamus:
relay station for sensory impulses, interpretation center for pain, temperature and touch
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epithalamus:
contains pineal gland
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hypothalamus:
home of homeostasis, controls and integrates autonomic nervous system (sympathetic and parasympathetic), receives sensory impulses from internal organs, controls pituitary gland and links endocrine and nervous systems, very little if any conscious control can be exerted here
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cerebral cortex:
gray matter surface
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longitudinal fissure:
separates two hemispheres
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gyri:
folds (singular is gyrus)
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sulci:
grooves (singular is sulcus)
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corpus callosum:
bridge connecting two hemispheres
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motor areas:
control muscular movements
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sensory areas:
interpret sensory impulses
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association areas:
process emotions and intellect
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frontal lobe:
muscle movement, moods, aggression, smell, motivation
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parietal lobe:
touch, pain, balance, taste, temperature
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temporal lobe:
hearing, smell, memory, abstract thought, judgment
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cerebellum:
butterfly-shaped, below and behind the cerebellum two partially separated hemispheres connected by the vermis
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functions of the cerebellum:
coordinating muscular movements, maintaining posture, maintaining balance
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dura mater:
“tough mother”
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arachnoid:
“cobweb”, fibrous
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pia mater:
“tender mother”, contains the cerebrospinal fluid
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spinal nerves:
connect at roots, Dorsal root: sensory, Ventral root: motor
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mechanoreceptors:
pressure, vibration, texture
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thermoreceptors:
heat, cold
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pain receptors:
mechanical, thermal, chemical
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proprioceptors:
muscle length, position
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taste buds:
on tongue, palate and pharynx
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tastes:
salt, sweet, sour, bitter, umami
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sclera:
white outer wall of the eye
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cornea:
transparent front of the eye
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iris:
colored part of the eye, which contracts and expands to limit light
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pupil:
the hole in the center of the iris
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anterior chamber:
the space between the cornea and the lens, filled with aqueous humor
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rods:
more sensitive, but only perceive shades of grey
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cones:
color perception, less sensitive
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posterior chamber:
the big space inside the eye, behind the lens, filled with vitreous humor
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lens:
clear tissue that focuses light on the retina
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retina:
light-sensitive lining of the eyeball, containing the rods and cones
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fovea centralis:
pit in the center of the back of the eyeball, where the majority of receptors are located
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optic nerve:
the nerve that carries the optic information to the brain
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optic disk:
the “blind spot” where the optic nerve exits the eye, with no receptors
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photoreceptors:
the rods and cones that change the light into nerve impulses
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eyebrow:
ridge of hair above the eye that protects it from sweat, rain, and other debris
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eyelashes:
hairs along with edge of the eyelid
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auricle:
external, visible, flexible part, made of cartilage – also called the pinna
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external auditory meatus -:
Lined with hair and ceruminous glands
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tympanic membrane:
vibrates in response to sound (ear drum)
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helix:
outer protruding rim
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antihelix:
inner protruding rim
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scapha:
valley between helix and antihelix
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concha:
inner depression around the auditory meatus
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auditory ossicles:
the tiny bones of the inner ear, the malleus, incus and stapes oval window and round window: the stapes vibrates the oval window to set up vibrations inside the cochlea, and the round window is the pressure relief
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Eustachian tube:
equalizes pressure inside the middle ear
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cochlea:
hearing equilibrium
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semicircular canals:
kinetic
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