AP Psych Unit 1

nervous system

the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

central nervous system (CNS)

includes the brain, spinal cord, and interneurons; makes decisions for the body

nerves

bundled axons that form neural "cables" connecting the central nervous system with muscles, glands, and sense organs

reflex

a simple, automatic response to a sensory stimulus, such as the knee-jerk response; bypasses the brain

autonomic nervous system

the part of the peripheral nervous system that controls self-regulated actions of the glands and internal organs (such as the heart); consists of the sympathetic and parasympathetic system

sympathetic nervous system

arouses the body, mobilizing its energy in stressful situations; regulates "fight, flight, and freeze" response

peripheral nervous system (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body

somatic nervous system

controls voluntary skeletal muscles

parasympathetic nervous system

calms the body, conserving its energy; "rest and digest" response

neurons

a nerve cell; the basic building block of the nervous system

cell body

largest part of a typical neuron; contains the nucleus and much of the cytoplasm

dendrites

branchlike parts of a neuron that are specialized to receive information

axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

myelin

a fatty substance that helps insulate neurons and speeds the transmission of nerve impulses

synapse

the gap between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; also known as synaptic gap or synaptic cleft

glial cells

brain's "support staff;" protect, nourish, and clean up after neurons; maintains environment for neurons to function properly

reflex arc

the nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between

sensory neurons

found in the PNS; afferent neurons that approach & carry info to the CNS

motor neurons

found in PNS; efferent neurons that exit the CNS & carry info to muscles & glands

interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

action potential

a neural impulse; a brief electrical charge that travels down an axon; also called a depolarized state

All-or-Nothing Principle

the principle that once the electrical impulse reaches a certain level of intensity (its threshold), it fires and moves all the way down the axon without losing any intensity

depolarization

the process during the action potential when sodium is rushing into the cell causing the interior to become more positive

reuptake

picking up leftover transmitters by the presynaptic neurons

multiple sclerosis

myelin sheath destruction; disruptions in nerve impulse conduction (signals slowed down/blocked)

neurotransmitters

chemical messengers released into the synapse

excitatory neurotransmitters

encourage neurons to fire

dopamine

both excitatory and inhibitory; AFLAME (regulates attention, focus, learning, addictions, muscle movements, excitement); too little >> ADHD, Parkinson's disease & too much >> schizophrenic hallucinations

norepinephrine

excitatory; regulates energy & fight or flight response; too little >> lack of energy (depression) & too much >> anxiety, disturbed sleep; antidepressant: SRNIs >> norepinephrine increase

GABA

inhibitory; the most common inhibitory neurotransmitter in the brain; acts in opposition to glutamate; "Get a Break Already;" calms nervous system; too little >> insomnia, anxiety, epileptic seizures, Autism Spectrum Disorder (ASD), depression, impaired cognitive functioning, schizophrenia & too much >> hypersomnia/narcolepsy

Substance P

excitatory; regulates the perception of pain

refractory period

after firing, the neuron needs time to reset before firing again

resting potential

the state of a neuron when it's ready to fire but hasn't yet

threshold

-55mV; must be surpassed for electrical impulse to be triggered and sent down to axon

Myasthenia Gravis

autoimmune disorder where ACh receptors are attacked leading to muscle weakness

inhibitory neurotransmitters

block neural messages & decrease stimulation

serotonin

inhibitory; MASH (mood, sleep, attitude, hunger); too little >> depression, anxiety, OCD, insomnia & too much >> serotonin syndrome (mild to extreme); antidepressants: SSRIs >> serotonin increase

glutamate

excitatory; the most common excitatory neurotransmitter in the brain; CLAM (regulates communication, learning, acts in opposition to GABA, regulates memory); too little >> poor neural communication, fatigue, poor memory and concentration & too much >> migraines, seizures

endorphins

inhibitory; offers pain relief & positive emotions; natural painkillers released with intensive exercise

Acetylcholine (ACh)

both excitatory and inhibitory; M & M (regulates initiation of muscle memory and memory formation, consolidation, and retrieval); too little >> Alzheimer's disease, lack of muscle contraction, paralysis & too much >> muscle spasms

electrical

within nerve cells

chemical

between nerve cells