2.1 Biological Foundations of Behavior Flashcards
Neurons
Nerve cells.
Brain
The mass of nerve tissue incased in the skull that controls virtually everything we are and everything we do.
Soma
The cell body of a neuron that contains the nucleus of the cell and carries the cell’s metabolic functions.
Axon
The tube like part of a neuron that carries messages away from the cell body toward other neurons.
Terminal buttons
Swelling at the tips of axons from which neurotransmitters are dispatched into the synapse.
Neurotransmitters
Chemical messengers that transport nerve impulses from one nerve to the other.
Synapse
The small fluid filled gap between neurons through which neurotransmitters carry neural impulses.
Dendrites
Rootlike structures at the end of axons that receive neural impulses from neighboring neurons.
Sensory neurons
Neurons that transmit information from sensory organs, muscles, and inner organs to the spinal chord and brain.
Motor neurons
Neurons that convey nerve impulses from the central nervous system to muscles and glands.
Glands
Body organs or structures that secrete a product called hormones.
Hormones
Secretions from endocrine glands that help the body regulate bodily processes.
Interneurons
Nerve cells within the central nervous system that processes information.
nerve
a bundle of axons from different neurons that transmit nerve impulses.
Glial cells
Small but numerous cells in the nervous system that support neurons and form the myelin sheath found on many axons.
Myelin sheath
A layer of protective insulation that covers the axons of certain neurons and helps speed transmission of nerve impulses.
Nodes of Ranvier
Gaps in the myelin sheath that create noninsulated areas along the axon
Multiple Sclerosis MS
A disease of the central nervous system in which the myelin sheath that insulates the axons are damaged or destroyed.
Ions
Electrically charges chemical particles.
Resting potential
The electrical potential across the cells membrane of a neuron in its resting state.
Depolarization
A positive shift in the electrical charge in the neurons resting potential, making it less negatively charged.
Action potential
An abrupt change from a negative to a positive charge of a nerve cell. Also called neural impulse.
All or none principle
The principle by which neurons will fire only when a change in the level of excitation occurs that is sufficient enough to produce an action potential.
Refractory Period
A temporary state in which a neuron is unable to fire in response to continued stimulation.