neurons + neural transmission

neuron

the cells that make up and are within the nervous system

dendrites

receive incoming info (messages) in chemical form

do the listening

cell body/soma

contains the nucleus

nucleus

makes the decision to fire or not fire

control center

myelin sheath

fatty tissue that insulates the axon, speeding up the transmission of the message

node of ronvier

space between myelin sheath

schwann cell

non-neural (glial) cells in the CNS that form myelin sheath

axon

longest part of the neuron which the electrical message travels the length of

does the speaking

axon terminal buds

the end point of a neuron that releases neurotransmitters into the synapse hence sending the message on to the next neuron

“A. Term Buttons”

types of neurons: sensory (afferent)

receive info from sensory receptors throughout the body and send it to the brain

types of neurons: motor (efferent)

send info. from the brain to the body

mirror

activated when we watch others complete an activity, i.e yawning

glial cells

protect + provide nutrients for neurons

Approx. 85 billion of these in the human body and they make up abt. ½ of the volume in our brain and spine

True

T/F: neurons send messages in a process called neural transmission

resting potential

when a neuron is NOT firing

has a negative charge w/ mostly potassium ions inside and mostly sodium ions outside

polarization

at resting potential, when sodium ions are on the outside and potassium ions are on the inside

at homeostasis

homeostasis

normal, happy, resting state

action potential

“nerve impulse” — causes the neuron to fire

the electrical pulse or message that travels the length of the axon

“all-or-nothing” principle

when the nucleus decides to fire; it fires down the axon completely (all the way) or not at all, maintaining the same intensity the entire length of the axonintensity

intensity

the strength or power of message being relayed

ex) toilet flushing

depolarization

when the opposites (sodium + potassium ions) are no longer away from each other.

happens at action potential like a domino effect

refractory period

the period of time after firing that the neuron is focused on resetting, and therefore is unable to fire again

always trying to get back to homeostasis

types of neurotransmitters: excitatory

stimulate the firing which sends messages

glutamate is the major ______ neurotransmitter

types of neurotransmitters: inhibitory

slows the firing which stops or slows the message

GABA is the major __________ neurotransmitter

neurotransmitter

chemical substances that crosses the synapse to carry on the message to the next neuron

synapse

open space between 2 neurons

receptor sites

specific points on dendrites of neurons that receive specific types of neurotransmitters

acetylcholine (ACh) PR

enables muscle action; learning, memory

acetylcholine (ACh) ADs

undersupply - Alzheimer’s

dopamine PRs

movement, learning, attention, emotion

dopamine ADs

oversupply - schizophrenia, undersupply - tremors + Parkinson’s

serotonin PRs

mood, hunger, sleep, and arousal

serotonin ADs

undersupply - depression + OCD symptoms

norepinephrine PRs

associated w/ the sympathetic nervous system; increased blood pressure, alertness, and heart rate

norepinephrine ADs

undersupply - depressed mood

oversupply - anxiety

gamma amino butyric acid (GABA) PRs

major inhibitory neurotransmitter

gamma amino butyric acid (GABA) ADs

undersupply - seizures, tremors, difficulty sleeping (insomnia)

endorphins PRs

pain control + pleasure

endorphins ADs

associated w/ OCD

Addiction - opiates decreases the amount of endorphins naturally produced

agonists + antagonists

EXTERNAL substances that somehow interact with neurotransmitters at the receptor sites on dendrites of a neuron

agonists

mimics NT activity

a master key: works just like the original key but is not exactly the same

antagonists

blocks NT activity

a fake key: preventing the neurotransmitter from getting to its receptor site + doing its job

• friends key wouldn’t work