AP Psychology: Nervous System & The Neuron

Nervous System

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

Central Nervous System (CNS)

The brain and spinal chord.

Peripheral Nervous System (PNS)

Connects CNS to the limbs and organs, essentially serving as a communication relay going back and forth between the brain and the extremities.

Somatic Nervous System

The division of the PNS that controls the body's skeletal muscles. Also known as the skeletal nervous system.

Autonomic Nervous System

The part of the PNS that controls the glands and the muscles of the internal organs. Controls the sympathetic and parasympathetic nervous system.

Sympathetic Nervous System

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.

Parasympathetic Nervous System

The division of the autonomic nervous system that calms the body, conserving its energy.

Neuron

a nerve cell; the basic building lock of the nervous system.

Sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal chord.

Interneurons

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

Motor Neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.

Soma (Cell Body)

the neuron's life support center that also produces neurotransmitters.

Dendrite

The busy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

Axon

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

Myelin Sheath

a layer of fatty tissue that covers the axon which aides in the speed of neural impulses.

Action potential

A neural impulse, a brief electrical charge that travels down an axon.

Ions

electrically charged atoms.

Resting potential

The fluid interior of a resting axon has an excess of negatively charged ions, while the fluid outside the axon membrane has more positively charged ions.

Selectively Permeable

the axons surface is very selective about what it allows in.

Polarized

during the resting state of a neuron when the outside is positively charged and the inside is negatively charged.

Depolarized

axon is no longer at resting potential; outside is now negatively charged and the inside is now positively charged.

Refractory Period

Resting state after firing in which the neuron goes back to its polarized resting state.

Excitatory

accelerates neurons firing speed.

Inhibitory

Slows neurons firing speed.

Threshold

The level of stimulation required to trigger a neural impulse.

Synapse

the junction between the terminal branch of the synaptic gap.

Synaptic Gap

The tiny gap at the synapse in which neurotransmitters cross.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons.

Reuptake

a neurotransmitters re-absorption by the sending neuron.

Ach

enables muscle action, learning, and memory.

Dopamine

Influences movement, learning, attention, and emotion.

Serotonin

Affects mood, hunger, sleep, and arousal.

Norepinephrine

Helps control alertness and arousal.

GABA

A major inhibitory neurotransmitter

Glutamate

A major excitatory neurotransmitter; involved in memory.

Endorphins

Natural, opiate-like neurotransmitters link

Agonist

A molecule that may be similar enough to a neurotransmitter to bind to its receptor and mimic its effects.

Antagonist

A molecule that binds to receptors but blocks the neurotransmitters functioning.

The Endocrine System

The body's slow chemical communication system ; a set of glands that secrete hormones into the bloodstream.

Hormones

Chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.

Adrenal Glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress.

Pituitary Gland

the endocrine systems most influential gland. Helps regulate growth and controls other endocrine glands.