Nervous System Flashcards
Neuron
functional cell type
nervous system
collection of neurons that operate in a coordinated manner
dendrite
conducts an electrical signal from dendrite to axon terminal
cell body
part with nucleus
axon
long tubular extension of plasma membrane.
axon terminal
base of the axon. plasma membrane flares to create a number of sites for information transfer.
electrically excitable cell
an electrical signal can be conducted from the dendrite to the axon terminal.
polarized cell
charge changes through the cell
membrane potential
most cells are negative inside relative to the outside
depolarization
membrane potential moves from negative to positive
action potential
a wave of depolarization
hyperpolarize
membrane potential goes back to original 70
synapse
the space between two neurons
electrical synapse
cells linked by gap junctions
gap junction
space between two neurons
chemical synapse
neurotransmitter is released by exocytosis from pre-synaptic cells and opens an ion channel on the post-synaptic cell
neurotransmitter
low weight hydrophilic chemical signals. cannot move across the plasma membrane on the post-synaptic cell.
exocytosis
bubble opens to plasma membrane and neurotransmitter is released.
excitatory neurotransmitter
if the neurotransmitter causes the post-synaptic cell to depolarize
inhibitory neurotransmitter
if the neurotransmitter causes the post-synaptic cell to hyperpolarize
sensory neuron
transmits information about external stimuli as detected by sensory organs
interneuron
neurons found in circuits that are involced in the analysis and interpretation of sensory input
motor neuron
transmits information to muscles and glands
reflex
from motor neurons
cephalization
neurons concentrating in the anterior CNS
central nervous system
from cephalization
myelinated neuron
cell with myelin. conduct action potentials at a fast rate.
unmyelinated neuron
shorter and conduct action potentials at a normal rate.
neuroglia
non-electrically excitable cells that serve a support role
oligodendrocyte
myelinated neurons in CNS
ependymal cell
form the surface of the ventricles
satellite cell
provide nutrients to neurons in the PNS
schwann cell
myelinates neurons in the PNS
astrocyte
makes the blood-brain barrier.
neural tube
embryonic structure that develope into the brain and spinal cord.
notochord
forms from mesoderm cells after gastrulation. causes neural tube to form.
brain
consumes 20% of )2
somite (vertebra)
the bone part. separated by vertebral discs
spinal cord
your whole vertebral system
peripheral nervous system
nerves outside the CNS.
ventricles
4 of them
ventricular fluid
flows over the surface of the brain and to the lateral ventricles to complete the circulatory system.
somatic pns
nerve tracts originating from the brain. voluntary movement. senses.
autonomic pns
involuntary muscle movement.
sympathetic pns
emergency functions
parasympathetic pns
housekeeping functions
cerebral hemisphere=cerebrum
responsible for skeletal (voluntary) muscle contraction, learning, memory, emotion, and perception
diencephalon
thalamus, hypothalamus, epithalamus
thalamus
relay center for sensory input heading to the cerebrum
hypothalamus
body temperature, appetite, pituitary gland,
epithalamus
location of pineal gland, source of melatonin for sleep
cerebellum
movement and balance, important in learning and remembering motor skills.
brain stem
control of automatic functions: breathing, swallowing, digestion, heart rate, blood pressure
cranial nerves
12 pairs of nerves that pass from the brain to areas of the head, neck, chest, and abdomen.
vertebral disc
separates vertebrae.
