Biopsyc 385 exam 1 :(

monism

belief that mind and body are one thing

dualism

belief that mind and body are separate things

neuron

cell specialized for receiving, processing, and transmitting information

cell body (soma)

main part of neuron containing structures to keep the cell alive

nucleus

part of cell containing DNA and controlling cell activities

dendrite

branch-like structure that receives information from other neurons/sensory receptors

axon

long fiber that carries action potentials away from the cell body

axon hillock

area where the axon begins; initiates action potential

axon terminal

end of an axon that communicates with another cell

myelin sheath

fatty covering over many axons that increases neural transmission speed

node of ranvier

small gap between sections of myelin

glial cells

cells that support, nourish, protect, and regulate neurons

blood-brain barrier

protective system that filters what can move through the blood into brain tissue

microglia

glial cells involved in immune defense and cleanup in the nervous system

astrocytes

glial cells that provide support to neurons and help regulate their environment

oligodendrocytes

glial cells that produce myelin in the central nervous system

Schwann cells

glial cells that produce myelin around axons in the peripheral nervous system

membrane potential

difference in electrical charge between the inside and outside of a cell

resting potential

neuron's stable charge when it is not producing an action potential

ion

electrically charged atom or molecule

sodium (Na+)

positively charged ion with a higher concentration outside of the neuron

potassium (K+)

positively charged ion with a higher concentration inside of the neuron

chloride (Cl-)

negatively charged ion important in neural signaling and inhibition

concentration gradient

tendency of particles to move from high concentration to low concentration

electrical gradient

attraction or repulsion of ions based on electrical charge

electrochemical gradient

combined influence of concentration and electrical forces on an ion

selective permeability

cell membrane's ability to allow some substances through more easily than others

sodium-potassium pump

protein that uses energy to move 3 Na+ out and 2 K+ into the neuron, helping maintain the resting potential

depolarization

a change in membrane potential that makes the neuron less negative and generally more likely to fire

hyperpolarization

a change in membrane potential that makes the neuron more negative

threshold

membrane potential that must be reached to trigger an action potential

action potential

rapid electrical impulse that travels down an axon

all-or-none law

principle that an action potential occurs completely or not at all

refractory period

resting period after an action potential when a neuron cannot produce another action potential normally

relative refractory period

period when it is possible to produce another action potential, but it takes a lot of effort

propagation

movement of an action potential along an axon

saltatory conduction

rapid movement of an action potential from node to node along a myelinated axon

local neuron

neuron that communicates primarily through graded changes in membrane potential rather than long-distance action potentials

graded potential

small change in membrane voltage whose size depends on the strength of the input

synapse

junction where one neuron communicates with another

presynaptic neuron

neuron that sends the signal into a synapse

postsynaptic neuron

neuron that receives the signal from a synapse

synaptic cleft

tiny space between the pre- and postsynaptic cells

reflex arc

neural pathway involved in a reflex, including sensory and motor neurons

spontaneous firing rate

rate at which a neuron produces action potentials without a particular external stimulus

EPSP (excitatory postsynaptic potential)

graded potential that makes the postsynaptic neuron more likely to produce an action potential

IPSP (inhibitory postsynaptic potential)

graded potential that makes the postsynaptic neuron less likely to produce an action potential

excitation

neural activity that increases the likelihood of an action potential

inhibition

neural activity that decreases the likelihood of an action potential

temporal summation

combining of multiple signals arriving from the same location at different times

spatial summation

combining of signals arriving from different locations at the same time

summation

process where multiple EPSPs and IPSPs combine to influence a neuron reaching threshold

neurotransmitter

chemical released by a neuron that affects another cell across a synapse

neuromodulator

chemical messenger that produces broader and longer-lasting changes in neural activity

neurotransmitter receptor

protein that recognizes a specific neurotransmitter and responds to it

reuptake

process in which a released neurotransmitter is transported back into the neuron that released it

enzyme

protein that speeds up a chemical reaction

enzymatic breakdown

process of using enzymes to break down a neurotransmitter

diffusion

movement of molecules from high concentration to low concentration

synaptic vesicle

small membrane container that stores neurotransmitters in the axon terminal

exocytosis

process in which a vesicle fuses with the cell membrane and releases neurotransmitter into the synaptic cleft

presynaptic terminal

end of the axon where neurotransmitters are released

ionotropic receptor

receptor that directly opens an ion channel when activated by a neurotransmitter

metabotropic receptor

receptor that works indirectly to open ion channels; takes longer but also lasts longer

glutamate

major excitatory neurotransmitter in the brain

GABA

major inhibitory neurotransmitter in the brain

glycine

important inhibitory neurotransmitter, especially in the spinal cord

dopamine

a monoamine involved in movement, motivation, reward, and other functions

epinephrine

monoamine involved in arousal, attention, and other functions

serotonin

monoamine involved in mood, sleep, appetite, and other functions

endorphins

neuropeptides involved in reducing pain and influencing other behaviors

ATP

purine that can function as a chemical messenger and energy-related molecule

adenosine

purine neuromodulator involved in regulating neural activity

nitric oxide

gas messenger that can affect nearby neurons and blood vessels

endocrine system

system of glands that produce and release hormones

target cells

cells that have receptors for a particular hormone or chemical messenger

endocrine gland

gland that releases hormones into the bloodstream