Ch. 2 Biopsych Flashcards
nervous system
network of cells that carries info to and from all parts of the body
neuroscience
deals with structure & function of neurons and nervous tissue
neuron
basic cell that makes up the nervous system and receivds and sends messages within that system
dendrite
branchlike structure that receive messages from other neuronss
soma
cell body of neuron responsible for maintaining the life of the cell; contains nucleus
axon
tube-like structure or fiber attached to soma that carries the neural message to other cells
synapse
tiny gap between the ends of nerve fibers across which nerve impulses pass from one neuron to another; at synapse, impulse causes the release of neurotransmitted –> electrical impulse in next neuron
Do people use only 10% of brain?
yes; 10% of brain is neurons, 90% of glial cells
glial cells
grey fatty cells that provide support and insulation for the neurons to grow on and around, deliver nutrients to neurons, produce myelin to coat axons, clean up waste products and dead neurons, influence information processing and during prenatal development, and influence the generation of new neurons
oligodendrocytes
generate myelin in brain and spinal cord
Schwann Cells
generate myelin in neurons of the bodym
myelin
fatty substances produced by certain glial cells that coat the axons of neurons to insulate, protect, and speed up the neural impulse
nerves
bundles of axons coated in myelin that travel together through the body
neural impulse
inside & outside the cell is semi-liquid w/ ions
–> inside: negatively charged
–> outside: positively charged
negative ions are bigger than positive ions; cannot fit the “gates”
resting potential
state of neuron when not firing a neural impulse
action potential
state of neuron when dendrites are activated and cell receives stimulation from another cell
–>electrical charge reversal starts at axon part nearest to soma
–> “gates” open: inside cell positive, outside positive
–> at the end of the axon, message is transmitted to another cell
strong stimulus
causes neuron to fire more quickly and more neurons to fire
resting state
sodium ion gates close immediately after action potential passes; cell membrane pumps out sodium ions back out the cell
–> K+ ions move out
axon terminal
branch at the end of the axon
synaptic knob (terminal button)
rounded areas on the end of the axon terminals
synapse or synaptic gap
microscopic fluid-filled space between the synaptic knob of one cell and the dendrites or surface of the next cell
receptor sites
holes in the surface of the dendrites or certain cells of the muscles and glands which are shaped ot fit only certain neurotransmitters
–> when action potential reaches synaptic vesicles, the vesicles release their transmitter into the synaptic gap
–> next cell stimulated is a neuron, muscle, or gland
excitatory synapse
synapse at which a neurotransmitter causes the receiving cell to fire
inhibitory synapse
synapse at which a neurotransmitter causes the receiving cell to stop firing
agonists
chemical substances that mimic or enhance the effects of a neurotransmitter on the receptor sites of the next cell, increasing or decreasing the activity of that cell
antagonists
chemical substances that block or reduce a cell’s response to the action of other chemicals or neurotransmitters
acetylcholine
-stimulates skeletal muscles to contract, slows contractions in heart muscle
1st neurotransmitter identified, found at synapse between neurons and muscle cells
glutamate
nervous system’s major excitatory neurotransmitter
–> learning and memory, development of the nervous system
GABA (gamma-aminobutryic acid)
most common neurotransmitter producing inhibitory effect in brain; calms anxiety
serontonin
associated with sleep, mood, appetite
–> excitatory or inhibitory effect
dopamine
found in brain
–> low levels = Parkinson’s
–> high levels = Schizophrenia
endorphins
pain-controlling chemicals in body
–> has same effect as morphine
–> leads to addiction to heroin or opium
norepihephrine
both a neurotransmitter and a hormone that helps transmit nerve signals across nerve endings to another nerve cell, muscle cell or gland cell
–> increases heart rate and blood pumping from the heart.
–> increases blood pressure and helps break down fat and increases blood sugar levels to provide more energy to the body.
reuptake
process by which neurotransmitters are taken back into the synaptic vesicles
enzyme
complex protein that is manufactured by cells
spinal cord
long bundle of neurons that carries messages between the body and brain, responsible for very fast, lifesaving reflexes
afferent (sensory neurons)
carry messages from senses to spinal cord
efferent (motor neurons)nec
carry messages from the spinal cord to the muscles and glands