AP Bio Neurons

Acetylcholine

Neurotransmitter that can activate an action potential in a postsynaptic neuron

Action Potential

Begins when a stimulus reaches the dendrites of a neuron, triggering a number of cell membrane conductivity changes

Adaptation

Heritable trait that helps an organism, such as a plant or animal, survive and reproduce in its environment

Antiport

Carries two different ions or molecules in different directions

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands. Messages pass from soma to another cell.

Axon Hillock

Region of neuron where incoming electrical signals are summers and elecrical signals, the action potential is unlimited

Calcium

Second messenger that regulates many processes, including synaptic transmission, fertilization, secretion, muscle contraction, and cytokinesis

Cell Body

Also called the soma and contains the nucleus of the neuron

Neurotransmitter Receptor

Selectively senses and reacts to molecules coming from the presynaptic neuron

Specifically calcium in this case

Node of Ranvier

Gaps formed between the myelin sheath where the axons are left uncovered

Oxidative Phosphorylation

The production of ATP using electron transport chain and chemiosmosis. Electron tranport chain passes electrons and uses energy to create gradient, chemiosmosis stores energy in the gradient to make ATP.

Perception

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

Peripheral Nervous Gate

Potassium Gate

a protein in the membrane of neurons that changes shape and allows potassium ions out of the neurons once the axoplasm gains a positive charge due to the influx of sodium ions.

Reception

When the signal is detected when the ligand binds to receptor protein

Refractory Period

Period of time during which a cell is incapable of repeating an action potential

Repolarization

Inactivation gates of the sodium channels close, stopping the inward rush of positive ions, while potassium gates open. The cell comes back to resting potential.

Chloroplast

Organelle within plants and certain algae that is the site of photosynthesis

Cochlea

a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

Dendrite

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

Depolarizes

the process by which an axon becomes more positive

Desmosome

a type of intercellular junction in animal cells that functions as a rivet, fastening cells together

G protein

A GTP-binding protein that relays signals from a plasma membrane signal receptor, known as a G protein-coupled receptor, to other signal transduction proteins inside the cell.

Glial Cell

cells in the nervous system that support, nourish, and protect neurons

Glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

Repolarize

to relax; the atria and ventricles repolarize as the heart beats

Resting Potential

The difference in electric charge between the inside and outside of a neuron's cell membrane

Schwann Cell

Supporting cells of the peripheral nervous system responsible for the formation of myelin.

Sensory

Having to do with seeing, hearing, feeling, tasting, or smelling

Sensory Processing

interpreting sensory stimuli

Sensory Receptors

sensory nerve endings that respond to stimuli

Signal Transduction Pathway

The process by which a signal on a cell's surface is converted into a specific cellular response.

Sodium Gate

a protein in the membrane of neurons that changes shape and allows sodium ions into neurons once the neuromembrane is disturbed by stimulus that surpasses a threshold.

Sodium-Potassium Pump

a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell

Stimulus

a signal to which an organism responds

Hyperpolarized

when the membrane potential is more negative

Interneuron

a neuron that carries nerve impulses from one neuron to another

Ligand Gated Channel

An ion channel that is stimulated to open by the binding of a small molecule such as a neurotransmitter.

Lysosome

An organelle containing digestive enzymes

Mitochondria

Powerhouse of the cell

Motor Proteins

A protein that interacts with cytoskeletal elements and other cell components, producing movement of the whole cell or parts of the cell.

Myelin Sheath

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.

Neuron

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

Neutrotransmitter

a molecule that passes an impulse across a synapse

Substrate Phosphorylation

uses chemical energy to add phosphate ion to molecule of ADP

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Synaptic Cleft

The narrow gap that separates the presynaptic neuron from the postsynaptic cell.

Synaptic Terminal

A bulb at the end of an axon in which neurotransmitter molecules are stored and released.

Threshold Potential

The minimum membrane potential that must be reached in order for an action potential to be generated.

Transduction

conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret.

Tympanic Membrane

a membrane forming part of the organ of hearing, which vibrates in response to sound waves. In humans and other higher vertebrates it forms the eardrum, between the outer and middle ear.

Voltage Gated Channel

ion channel that opens because of a change in the charge distributed across the membrane where it is located