Chapter 5 Full Set

paradigm

a model; an example

perception

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

elucidate

to clarify, explain

myelin

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

propagate

produce, spread, increase

action potential

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

electrical resistance

The property of a material that resists the flow of charged particles through it; measured in ohms

conductance

the ease with which ions flow through a channel

perfuse

to force fluid to flow through a lumen or a tube

axonal transport

The transportation of materials from the neuronal cell body to distant regions in the dendrites and axons, and from the axon terminals back to the cell body.

learning

a relatively permanent change in an organism's behavior due to experience

memory

the persistence of learning over time through the storage and retrieval of information

sensitization

an increase in behavioral response after exposure to a stimulus

habituation

an organism's decreasing response to a stimulus with repeated exposure to it

ganglia

Collections of nerve cell bodies

gill withdrawal reflex

in aplysia, a protective reflex in which the gill is retracted in response to touch

short term memory

activated memory that holds a few items briefly, such as the seven digits of a phone number while dialing, before the information is stored or forgotten

long term memory

the relatively permanent storage of information

Presynaptic synapse

A synapse between an axon terminal and another axon's terminal that can be either excitatory or inhibitory

impinging

have an effect or impact, especially a negative one

G-protein

coupled to a metabotropic receptor; conveys messages to other molecules when a ligand binds with and activates the receptor

adenylate cyclase

Activated by a G-protein. Converts ATP to cyclic AMP in response to an extracellular signal.

cyclic AMP

Secondary chemical messenger that directs the synthesis of protein by ribosomes

Protein Kinase A

A molecule of cAMP activates Protein Kinase A, which can phosphorylate (energize) many proteins.

Limulus polyphemus

Atlantic Horseshoe Crab

prominent

standing out so as to be easily seen

facet

smooth, nearly flat surface

oomatidia

structures with rods (light sensitive) and cones

photoreceptor

a receptor cell that responds to light

eccentric cell

the eccentric cell is a specialized secondary neuron located at the center of each individual visual unit, known as an ommatidium

Mach Bands

illusory (psychological) light and dark bands near a light-dark border

optic nerve

carries neural impulses from the eye to the brain

Bloch's Law

The principle that all stimuli in which the product of time and intensity is constant will be equally detectable.

lateral inhibition

The pattern of interaction among neurons in the visual system in which activity in one neuron inhibits adjacent neurons' responses.

inhibitory

slows neuron's firing speed

disinhibition (Limulus eye)

the increase in an illuminated unit's firing rate that occurs when a third ommatidium inhibits a second unit, thereby releasing the first from the lateral inhibition previously exerted by that second unit.

reciprocal inhibition

the mutual suppression of neural firing between two neighboring visual units, where the activity of each unit is reduced by an amount proportional to the other's level of excitation above a specific threshold.