Nervous System Flashcards
basic unit of nervous system
neuron
dendrite part of neuron
short branches off of cell body/cyton they receive signals
cell body/cyton
contains the organelles of the neuron and does the metabolic activities
axon
long fiber that connects the cell body
to the terminal branches
schwann cells
produce myelin
myelin
fatty insulation on the axon
nodes of ranvier
space in between schwann cells/mylin on axon
multiple sclerosis
immune system attacks your mylin
terminal branches
send signals from the axon to the synaptic knobs
synaptic knobs
the electrical signal causes the release of neurotransmitters from vesicles
synapse
space between two neurons
types of neurons
~sensory neurons
~interneurons
~motor neurons
sensory neurons
send messages from receptors to the brain and spinal cord
interneurons/associative neurons
relay messages from neuron to neuron (very short)
motor neurons
send messages from brain and spinal cord to effectors
effectors
muscles and glands
receptors
eyes, ears, mouth, nose, skin
nerves
bundles or neurons
charges of a neuron at rest
outside = positive
inside = negative
when a membrane is polarized
it is separated
sodium-potassium pump
pumps potassium into the cell and sodium out of the cell
stimulus
an outside factor that causes an impulse
ex. light, heat, sound, pain
stimulus
an outside factor that causes an impulse
ex. light, heat, sound, pain
path of an impulse
a stimulus causes a receptor to produce an impulse that goes to the brain to produce a response
action potential
wave of depolarization and re polarization along the neuron
depolarization
sodium gates open when there is enough stimulus and positively charged sodium goes into the cell (cell becomes positive inside negative outside) then the potassium gates open and the positive potassium leaves (repolarization, cell becomes negative)
resting charge of inside the neuron
-70 mV, negatively charges
how does mylin effect the depolarization/repolarization wave?
since the pumps can only be at the nodes of ranvier since the pumps can be under mylin, the signal travels faster
saltatory conduction
when the depolarization/repolarization wave travels faster due to mylin being on the nerve membrane
how the signal crosses the synapse
the electrical gets converted to a chemical signal called neurotransmitters that cross the synapse and bind to the receptors of the next nerve. enzymes then break down the old neurotransmitters
neuromuscular junction
a place where the motor end plates of a neuron is nea muscle and the neurotransmitters bind to the muscle and cause contractions
protist nerve regulation
they respond directly to stimulus and have irritability, no neurons or nervous system
irritability
whole organism response to stimulus
hydra nervous regulation
they have a nerve net and their neurons have two-way transmissin. they have irritability
worm nervous regulation
they have two central nerve cords with one-way transmission. ganglia serve as their brains.
ganglia
spots in a worm where smaller nerves branch off from the two central nerve cords
nervous regulation in humans
central nervous system with brain and dorsal spinal cord. peripheral nervous system with nerves to and from receptors and effectors
brain
protected by cranium, is the computing center
meninges membrane
the membrane around the brain
cerebrospinal fluid
fluid that surrounds the brain
cerebrum
the largest part of the brain, it’s divided down the middle into right and left. controls volentary body actions, thought, and many receptors abilities. has unmylinated and myelinated cells. controls data between both sides of the cortex
corpus callosum
nerves that cross the brain hemispheres
hippocampus
it is where memory comes from although long term memory is stored in the cerebrum
cerebellum
coordinates movements
medulla oblongata
controls your reflexes
hypothalamus
controls your body temperature, blood pressure, sleep, emotions and it regulates the pituitary gland
reflex
and action that you are born with that requires no thought
instinct
a sequence of reflexes you are born with (butterflies migrating)
conditioned reflex
learned behavior together with a reflex like when dog training
conditioned response
when you associate one stimulus with another. you learn it from someone else. like fear
habit
a quick behavior that is thoughtless. repition and desire
imprinting
copying the behavior of the assumed parents
spinal cord
a bundle of nerves that goes from the medulla down the vertebral column. protected by the vertebre
what controls reflexes
the spinal cord
reflex arc
stimulus activates a sensory neuron that sends a signal to the spinal cord when sends a signal to the motor neuron
peripheral nervous system
made of somatic nervous system and autonomic nervous system
somatic nervous system
deals with voluntary motions
autonomic nervous system
made of parasympathetic and sympathetic nervous systems, controls involuntary events
parasympathetic nervous system
causes for relaxation
sympathetic nervous system
causes for tension (when u feel like something is an emergency)
order of things in the eyes from out to in
cornea
iris
pupil
lense
sclera
choroid coat
retina
sclera
the whites of the eyes
cornea
place where light enters the eye. provides focus
choroid coat
beneath the sclera, stops reflection inside eye
iris
controls the amount of light let into the eye, colored
pupil
hole at the center of the iris where light enters
lens
focuses light on the retina