Unit 1.1: Biological Bases of Behavior Vocab

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

the brain and spinal cord

peripheral nervous system

connects the central nervous system to the limbs and organs. (communication relay back and forth between the brain and the extremities)

somatic nervous system

division of the peripheral nervous system that controls the body's skeletal muscles. AKA the skeletal nervous system

autonomic nervous system

the part of the peripheral NS that controls the glands and muscles of the internal organs. controls the sympathetic and parasympathetic nervous systems

sympathetic nervous system

the division of the autonomic NS that arouses the body, mobilizing its energy in stressful situations. (fight or flight)

parasympathetic nervous system

the division of the autonomic NS that calms the body, conserving its energy. (rest and digest)

reflex 

a simple, automatic response to a sensory stimulus, such as the knee

neuron

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

sensory neurons

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

interneurons

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

motor neurons

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

soma

the neuron's life support center that also produces neurotransmitters (cell body)

dendrite

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 (the thicker the sheath, the faster the impulse)

Nodes of Ranvier

spaces between the myelin

Schwann cell

produces myelin

action potential

a neural impulse; a brief electrical charge that travels down an axon

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 axon's 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 negatively charged and inside is now positively charged

refractory period

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

excitatory

accelerates neuron's firing speed

inhibitory

slows neuron's 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; AKA synaptic cleft

reuptake

a neurotransmitter's reabsorption by the sending neuron

ions 

electrically charged atoms