unit 2 : biological bases Flashcards
dendrites function
- receives info
- conducts it toward cell body
axon function
passes messages through terminal branches to neurons, muscles, or glands
myelin sheath
- what axons encased in
- insulates and speeds up impulses
action potential
- leads to depolarization
- a neural impulse, brief electrical charge that travels down an axon. makes body ready to move
resting potential
- state of a neuron when not sending a signal
- has a slightly negative charge compared to the outside to help get ready to send a signal
refractory period
- leads to repolarization
- period of inactivity after a neurons has fired
excitatory signal
- increases likelihood of a neuron firing
- makes inside of neuron more positive (depolarization)
inhibitory signal
- decreases likelihood of a neuron firing
- makes inside of a neuron more negative (hyperpolarization)
all-or-none
- a neurons reaction of either firing or not
- no in between / change in strength
communication that occurs between neurons within the synapse
neurotransmitters (chemical messengers) are released into the synapse
neurotransmitters
- chemical messengers that cross the synaptic gaps between neurons
- travels to bind to the receptor site on the recieving neuron
reuptake
the sending neuron reabsorbs the excess neurotransmitters
acetylcholine (Ach)
- neurotransmitters
- increases learning & memory
- ex : you see a runner go by and recall what they were wearing
dopamine (DA)
- neurotransmitters
- feel-good actions
- motivation
- coordination & focus
- ex : too little will make you shaky, too much can make you dopey
epinephrine (adrenaline)
- neurotransmitters
- fight or flight response
- boosted energy
- increases breathing
ex : a shot from an epi pen gets you ready to fight an allergic reaction
norepinephrine (NE)
- neurotransmitters
- controls the body’s fight or flight response
- boosted heart rate
- improved attention & focus
ex : you hear a loud noise behind you at night, your ready to run of defend yourself (epinephrine), norepinephrine makes you alert and focused to respond quick
serotonin (SE)
- neurotransmitters
- keeps you calm and happy
- helps you fall asleep
- social behavior
ex : your relaxing on a peaceful day watching the sunset, you feel happy and calm (serotonin)
GABA
- neurotransmitters
- reduces anxiety
- promotes relaxation
- improves sleep
ex : you had a stressful day at school but once you get home and start relaxing your anxious thoughts go away (GABA)
endorphins
- neurotransmitters
- reduces pain
- relives stress
- boosts mood
ex : runners high, eurphoria
agnostic drugs
- a molecule that binds to a receptor site, stimulating a response
- amplifies normal sensations
antagonist drugs
- by binding to a receptor site, inhibits / blocks a natural response
ex : botox (blocks muscle contraction)
sensory neurons (afferent)
neurons that carry incoming info from sensory receptors to the brain & spinal cord
motor neurons (efferent)
neurons that carry outgoing information from the brain & spinal cord to muscles and glands (instructions)
interneurons
acts as connectors, relaying signals between sensory & motor neurons
