unit 1.3(the neuron and neural firing)

glial cell

nourishment for cells

neurons

nerve cells, 90 billion in brain

reflex arc

a neural pathway that controls a reflex, which is an automatic, involuntary response to a stimulus

sensory neurons

sense things from the environment

motor neurons

moves muscles

interneurons

specialized nerve cells that connect sensory and motor neurons within the central nervous system (brain and spinal cord)

neural transmission

an electrical signal travels down the axon

all-or-nothing principle

they fire or don’t

action potential

neurons firing

depolarization

when there’s a shift on a neurons electrical charge that allows an action potential to occur

refractory period

restore the electric charge

resting potential

sitting waiting to fire

reuptake

neuron reabsorbs a neurotransmitter it previously released into the synapse after it has performed its function

firing threshold

the minimum level of stimulation needed to trigger a neural impulse

multiple sclerosis

the loss of muscle control resulting from a deterioration of myelin sheath

myasthenia gravis

autoimmune disorder that disrupts the communication between nerves and muscles, causing muscle weakness and fatigue

excitatory

increases the likelihood of a neuron firing an action potential

inhibitory

prevents or decreases the likelihood of a neuron firing

neurotransmitters

chemical messengers that transmit signals between neurons in the brain

dopamine

(excitatory & Inhibitory)- “reward chemical” happy feeling

Serotonin

(inhibitory)- associated with mood; depression

Norepinephrine

(excitatory)- alertness

glutamate

(excitatory)- primary excitatory

GABA

(Inhibitory)- Gamma: aminobutyric acid, slows down movements, associated with alcohol

Endorphins

(Inhibitory)- Natural pain killer

Substance P

(Excitatory)- pain signals in the nervous system

Acetylcholine(ach)

(Inhibitory and Excitatory)- muscle movement

Hormones

chemical messengers secreted by endocrine glands that travel through the bloodstream to influence various bodily functions and behaviors

adrenaline

fight or flight response(stressful situations)

leptin

signals the brain about the body’s fat stores

ghrelin

signals hunger(produced in stomach)

melatonin

regulates sleep- wake cycle(pineal gland)

oxytocin

“love hormone” social bonding, trust, and feelings of attachment

agonist

chemical substance that binds to a receptor in the brain and mimics the action of a naturally occurring neurotransmitter

antagonist

a substance/drug that blocks or inhibits the activity of a specific neurotransmitter by binding to its receptor sites

reuptake inhibitors

type of drug that prevents the reabsorption of neurotransmitters in the synapse (SSRI)

psychoactive drugs

substances that cause changes in the normal activities of the central nervous system

stimulants(caffeine, cocaine)

substances that increase activity in the body and brain, enhancing alertness and energy levels

depressants(alcohol)

drugs that reduce arousal and stimulation in certain areas of the brain by slowing down bodily functions and neural activity

hallucinogens(weed)

a group of drugs that alter a perosn’s perception of reality

opioids(heroin)

drugs that interact with the body’s opioid receptors in the brain, used to relieve pain(blocks pain signals)

tolerance

a decreased response to a drug over time

addiction

compulsive, uncontrollable behavior(strong craving for substance)

dependence

physiological need for a substance

withdrawal symptoms

the mental and emotional challenges that occur when someone stops using a substance after they’ve been dependent on