1.3 Flashcards
neurons
a nerve cell
Glial cells
cells in the nervous system that support, nourish, and protect nuerons
Reflex Arc
a simple spinal feflex pathway
sensory nuerons
carry messages from the body to the brain/spinal cord about sensations we perceive (sensory)
Motor Neurons
carry messages from the brain/spinal cord to the body telling our body (skeletal muscles) to move (motor)
Internuerons
connect sensory and motor neurons (in the spinal cord of CNS)r
refractory period
pause between firings (action potential cannot occur)
resting potential
positive-outside/negative-inside state of a neuron
all-or-nothing principle
neuron will fire full strength or not at all
depolarization
loss of the positive-outside/negative-inside resting potential state
myasthenia gravis
disease where ACh is blocked and muscles cannot contract (causes weakness or paralysis)
Reuptake
when the neurotransmitter is reabsorbed by the sending neuron
Inhibitory neurotransmitters
make action potential less likely
excitatory neurotransmitter
make action potential more likely
serotonin
- Involved in mood regulation
- Involved in sleep and arousal regulation
- Involved in regulation of appetite and digestion
Serotonin (undersupply)
- Linked with depression, but the mechanism is not fully understood
- Linked with anxiety, worry, nervousness,
- Linked with sleep difficulties
Glutamate
- Major excitatory neurotransmitter
- Makes it more likely for a neuron to fire
- Increases brain activity
- Involved in learning and memor
Endorphins
- Regulates the perception of pain (acts as the brain’s natural opiates)
- Enhances mood (feelings of euphoria and pleasure)
Acetycholine
- Enables movement (transmitted from motor neurons to muscles)- all movement involved ACh
- Involved in learning and memory (many ACh receptors are in the hippocampus)
dopamine
influences movement, learning, attention and emotion
Norepinephrine
- Involved in promoting wakefulness, alertness, and arousal
- Released in response to stress and helps initiate the fight or flight response
GABA
- Major inhibitory neurotransmitter
- Makes it less likely for a neuron to fire
- Reduces brain activity
Substance P
- Involved in the perception of pain (helps transmits pain signals from the body’s skin, muscle, and tissues to the central nervous system)
- Plays a role in promoting inflammation in response to injury
Hormones
internal, long-lasting
Leptin
hunger (suppression)
Melatonin
sleep
Adrenaline
fight or flight
Ghrelin
hunger (stimulation)
Oxytocin
labor, lactation, love
Psychoactive drugs
drugs that affect the mind
Agonist molecule
binds to receptor & encourages neural firing
Reuptake inhibitors
block reabsorption of neurotransmitters back into sending neurons axon terminals
Depressents
decrease neural activity
Antagonist molecule
binds to receptor & blocks neurotransmitters, discourages neural firing
stimulants
increase neural activity
Stimulants examples
caffeine and cocaine
Depressant example
alcohol
Hallucinogens
cause distortions in perception and/or cognition
Hallucinogens examples
Marijuana/THC
Opioids
act as pain relievers
Opioids example
heroin
tolerance
brain attempts to restore balance, neurons and synapses change to accommodate increased activity or use of drug
Withdrawal
verse symptoms associated with sudden drop in drug use
Addiction
brain pathways of reward and reinforcement triggered by dopamine, synapses in prefrontal cortex are changed and decisions are focused on addictive drug behavior
