Afferent—fibers, particularly sensory, that travel toward the central nervous system.
Aneurism—an unusually large expansion in the wall of an artery that causes weakness and possibly tears in the arterial wall.
Anions—negatively charged ions.
Axons—the output of a brain cell or neuron that transmits an action potential and connects to other neurons; the wire-like parts of neurons along which electrical signals travel.
Cations—positively charged ions.
Caudal—of, at, or toward the tail; toward the posterior end of a body.
Congenital defects—the abnormal anatomy a person is born with.
Contralateral—of or pertaining to the opposite side.
Cranium—the skull of a vertebrate; the part of the skull that encloses the brain.
Cytosol—the fluid within a cell; the water-soluble components of the cytoplasm.
Demyelination—damage to the myelin sheath where the myelin is removed from the axon.
Dendrites or dendritic arbors—branches or fine branches that extend from the neuron’s cell body and that receive input signals for the neuron.
Depolarization—the movement of chemicals that may contribute to the development of an action potential in a neuron. Specifically, when the membrane potential becomes less negative and closer to threshold to generate an action potential.
Efferent—fibers, particularly motor pathways, that travel away from the central nervous system.
Efflux—the act of flowing outward; flow out of a neuron or glial cell.
Endolymph—a special fluid found in the inner ear used for sensing balance and for transmitting sound waves.
Equilibrium—the sense of balance; the ability to perceive directions such as up and down.
Etiology—the causes of a disease or condition, or how that disease or condition comes about.
Ganglion (singular); Ganglia (plural)—a collection of cell bodies that is located outside of the central nervous system.
Glia or Glial cells—types of brain cells that support neurons or nerve cells; cells in the nervous system that lack the ability to communicate by sending electrical signals.
Gustatory—of or relating to taste or tasting; the sense of taste.
Gyrus (singular); Gyri (plural)—a ridge or fold in brain tissue. The combination of gyri and sulci is what gives the brain its convoluted and folded appearance.
Hyperpolarization—the movement of chemicals that contribute to the cessation of an action potential in a neuron.
Influx—the act of flowing inward; to flow into a neuron or glial cell.
Innervate—to communicate by neurons; stimulating through nerves or axons.
Ion channel—a protein in the cell membrane that forms a pore and lets certain ions through when open.
Ipsilateral—Latin meaning “same side.”
Ischemia—insufficient blood supply caused by vasoconstriction or a local obstacle to the arterial flow.
Limbic system—the emotional circuit of the brain.
Macula—a region of the retina that has the greatest ability to sense light.
Myelin—a protective covering of a neuron’s axon that helps transmit nerve impulses faster.
Nerves—bundles of axons that exist outside of the central nervous system and are part of the peripheral nervous system.
Neurons or Nerve cells—specialized brain cells that allow communication and transmission of information among one another and with target cells and tissues throughout the body.
Neuroscience—the study of structure, function, development, physiology, pharmacology, and pathology of the nervous system.
Neurotransmitters—chemicals used to activate neurons and begin the process of depolarization.
Nucleus (singular); Nuclei (plural)—a collection of cell bodies that is located within the central nervous system.
Olfaction—the sense of smell; the act of smelling.
Pathophysiology—the abnormal functioning of a body component as a result of disease, injury, or some other medical condition.
Photoreceptors—specialized proteins that respond to light.
Physiology—the normal functions of a particular organ, tissue, cell, or other bodily component.
Primary visual cortex—also called the striate cortex of the occipital lobe because it looks striped. It is the location where vision begins to be integrated.
Propagate—to transmit an action potential; how an action potential travels toward its target cell.
Proprioception—the sense of where one’s body is in space, particularly for identifying limb position.
Receptor fields—areas or regions that receive external stimuli such as touch.
Retina—the photosensitive lining of the back of the eye where images are focused.
Rostral—of or relating to the rostrum; toward the nose or beak.
Somatosensation—body senses, such as temperature, pressure, and pain.
Sulcus (singular); Sulci (plural)—a trough or groove in brain tissue. The combination of gyri and sulci is what gives the brain its convoluted and folded appearance.
Synapse—a physical connection of two neurons where a chemical signal is released from an action potential; the communication points between two neurons.
Tracts—a long group of fibers (axons) that transmits information electrically within the central nervous system.
Vesicles—small membranous sacs containing signaling molecules known as neurotransmitters.
Viscera—organs that are found in the body, especially those located in the abdominal cavity of an animal or human.