4.01 Neurons and synapses Flashcards
a network of cells that carry info to and from all parts of the body
nervous system
broad science that explores the structures and functions of the brain, enruons, nerves and nervous tissue
neuroscience
___ psychology, also called behavioral neuroscience, focuses on the biological bases of psychological processes
biological
first doctor to imagine that the nervous system was made up of individual cells
Ramon y Cajal
neuron structures that receive signals from other neurons
dendrites
neuron structures that is the cell body
soma
neuron structures that carry signals out of the cell
axons
neuron structures that insulate axons and make signal transmission more efficient
myelin sheath
__ cells serve many support functions in the nervous system
glial
8 functions of glial cells
- provide structure where neurons can develop
- hold neurons in place
- guide migrating neurons to form the outer layers of the brain
- get nutrients to neurons
- clean up remains of dead neurons
- provide insulation for neurons by making myelin
- control synaptic connectivity during development
- assist in learning and memory
major __ disorder is characterized by lower numbers of specific glial cells
depressive
___ is a disease characterized by higher numbers of specific glial cells
schizophrenia
glial cells that produce myelin for the brain and spinal cord
oligodendrocytes
glial cells that produce myelin for the neurons of the body
Schwann cells
two components of the central nervous system
brain and spinal cord
neurons of the body make up the __ nervous system
peripheral
term for myelin-coated axons in the central nervous system
tracts
term for myelin-coated axons in the peripheral nervous system
bundles
axons in the (CNS or PNS?) are more likely to be permanently damaged
CNS
small sections of axons that are not covered by myelin
nodes
disease in which the myelin sheath is destroyed, which leads to loss of neural functioning in damaged cells
multiple sclerosis
a neuron that is not firing is at __
rest
a charged particle
ion
resting potential of most cells
-70 millivolts
describes a cell membrane that allows some substances to cross, but not others
semipermeable
a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory
action potential
different in charge across a cell mebrane
electrical potential
5 steps in an action potential
- resting potential
- threshold
- action potential
- hyperpolarization
- resting potential
two things a strong message can do to affect neuron firing
- make the neuron fire repeatedly
- make more neurons fire
molecule that carries a message across the synapse
neurotransmitter
sac full of neurotransmitters at the presynaptic terminal
synaptic vesicle
fluid-filled space between neurons
synapse
a “gate” on a dendrite ion channel
receptor site
synapses that activate cells
excitatory synapses
synapses that turn cells “off”
inhibitory synapses
a chemical that blocks or reduces the effects of a neurotransmitter
antagonist
a chemical that mimics or enhances the effects of a neurotransmitter
agonist
neurotransmitter that activates skeletal muscle
acetylcholine (ACh)
acetylcholine antagonist, prevents muscles from contracting
curare
acetylcholine agonist, causes convulsions
black widow spider venom
neurotransmitter involved in movement and pleasure
dopamine
disease characterized by low levels of dopamine
Parkinson’s
disease characterized by high levels of dopamine
schizophrenia
neurotransmitter associated with sleep, mood, anxiety and appetite
serotonin
low levels of serotonin are associated with __
depression
excitatory neurotransmitter that plays an important role in learning, memory and synaptic plasticity; after injury or disease, it is associated with cell death
glutamate
the ability of the brain to change connections among its neurons
synaptic plasticity
an inhibitory neurotransmitter that can calm anxiety
gamma-aminobutyric acid (GABA)
a GABA agonist, which can have a calming effect
alcohol
a group of neuropeptides that prevent cells from firing pain signals
endorphins
class of drugs that are addictive because they prevent addicts from producing endorphins (causing an inability to control pain without the drugs)
opiates (morphine and heroin)
process during which neurotransmitters stay in the synapse and are taken back into the presynaptic neuron
reuptake
drug that blocks the reuptake of dopamine, causing users to be happy longer, as the dopamine lingers in the synapse
cocaine
process by which neurotransmitters are broken down by enzymes
enzymatic degradation
diazepam (Valium) is an antianxiety medication and an agonist for __
GABA
SSRI
selective serotonin reuptake inhibitor; drug that prevents the reuptake of serotonin and improves modd
