Glossary terms will appear here



Action Potential- (nerve impulse) transient all or none reversal of a membrane potential produced by regenerative inward currents in excitable membranes (for more information see ‘The Nervous and Endocrine Systems’.


Ganglion- a cluster of nerve cell bodies


G-Protein- a protein in the plasma membrane that binds to GTP and becomes activated and converts GTP to GDP (see page 913 of the General Biology Text)


Microvilli- miniature tubular elongations on a surface membrane


Opsins- visual pigment molecules made up of proteins


Otolith- a solid deposit or ear stone which rests in a bed or sensory hair cells in fish.


Photon-a discrete particle containing a fixed amount of light energy; correlating directly to the wavelength of the light that it is traveling in.


Photopigment Molecule- These contain two connected opsin proteins that change their protein configurations when the photopigment molecule absorbs photons of light.


Rhodopsin- a visual pigment molecule bound to a retinal molecule. There are the visual pigments of rods in the eye


Scolopida- A specialized cluster of sensory cells


Setae- long hair like processes