ap psych - unit 1, topic 1.3B

neural transmission, neurotransmitters, & hormones

neural transmission

occurs when a neuron is activated, or fired - sends out an electrical impulse (transfer of information between neurons)

action potential

the change in electrical potential that propagates along the axon of a neuron during the transmission of a nerve impulse or the contraction of a muscle

all-or-nothing principle

a neurons reaction of either firing with a full strength response or not firing

depolarization

when there's a sight in a neuron's electrical charge that allows an action potential to occur

refractory period

in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state

resting potential

the condition of the neuron when its resting - the value its membrane potential keeps as long as its not receiving stimulation or undergoing an action potential

reuptake

a neurotransmitters’ re-absorption by the sending neuron

threshold

the level of stimulation required to trigger a neural response

multiple sclerosis

a chronic inflammatory disease of the central nervous system, causing motor & sensory impairment by progressive demyelinization (deterioration of myelin sheaths)

myasthenia gravis

a chronic autoimmune disorder in which antibodies destroy the communication between nerve cells & muscles, resulting in weakness

excitatory neurotransmitters

describes a neurotransmitter that causes a postsynaptic neuron to propagate more action potentials

inhibitory neurotransmitter

describes a neurotransmitter that causes a postsynaptic neuron to propagate fewer action potential

dopamine

a neurotransmitter that:
→ helps the brain coordinate & initiate physical movement
→ is released in response to pleasurable experiences (makes you feel good & more likely to do that thing again)
→influences motivation & goal-directed behavior
→influences cognition & executive function

oversupply: schizophrenia, euphoria, psychosis

undersupply: parkingson's disease, adhd

serotonin

a neurotransmitter that regulates mood, sleep, arousal, appetite, & digestion

oversupply: serotonin syndrome

undersupply: linked with depression, anxiety, worry, nervousness, sleep difficulties, etc.

norepinephrine

a neurotransmitter that:
→is involved in prompting wakefulness, alertness, & arousal
→is released in response to stress & helps initiate the fight or flight response

oversupply: stress, anxiety, associated with manic episodes in bipolar disorder

undersupply: depressed mood, sleep problems

glutamate

a major excitatory neurotransmitter that makes it more likely for a neuron to fire & increases brain activity, also involved in learning & memory

oversupply: seizures, migraines

undersupply: cognitive impairments, learning deficits

GABA

a major inhibitory neurotransmitter that makes it less likely for a neuron to fire & reduces brain activity

oversupply: drowsiness, muscle weakness, cognitive impairment due to reduced brain activity

undersupply: anxiety, insomnia, chronic pain, depressed mood, seizures

endorphins

a neurotransmitter that:
→regulates the perception of pain, acting as the brain's natural opiates
→enhances mood, feelings of euphoria & pleasure
→can reduce the body's stress response

oversupply: n/a

undersupply: increased sensitivity to pain

substance p

a neurotransmitter that:
→is involved in the perception of pain, helps transmit pain signals from the body's skin, muscle, & tissues to the central nervous system
→plays a role in promoting inflammation in response to injury
→involved in regulating emotion & social behavior

oversupply: n/a

undersupply: n/a

acetylcholine

a neurotransmitter that:
→enables movement, transmitted from motor neurons to muscles
→is involved in learning & memory, many ACh receptors are in the hippocampus

oversupply: blurred vision, nausea & vomiting, slow heart rate, difficulty breathing, paralysis due to wearing out ACh receptors

undersupply: myasthenia hravis, alzeimer's disease

hormones

chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, & affect other tissues

adrenaline

a hormone that activates the sympathetic nervous system, like fight or flight

leptin

a hormone that helps manage energy, signals the hypothalamus the body has enough fat stored to function normally (tells you when you're full)

ghrelin

a hormone your stomach produces & releases, it signals your brain when your stomach is empty & it's time to eat (tells you when you're hungry)

melatonin

a hormone known to regulate sleep & wake cycles, its released by the pineal gland into the bloodstream when sleep is prompted

oxytocin

a hormone found in mammals that's associated with boding, empathy, & trust, produced by the hypothalamus & increased by the pituitary gland

pituitary gland

the endocrine system's most influential gland - under the influence of the hypothalamus, regulates growth & controls other endocrine glands