ectoderm

n. the outermost of the primary germ layers of a developing embryo. Structures derived from ectoderm include skin and nails, hair, glands, mucous membranes, the nervous system, and external sense organs (e.g., ears, eyes). —ectodermal adj.

Browse dictionary by letter

a b c d e f g h i j k l m n o p q r s t u v w x y z

Psychology term of the day

February 20th 2025

tickle experience

a sensation produced by impulses from adjacent skin receptors that are stimulated lightly in rapid succession. It is assumed that the receptors involved are also responsible for the sensations of itch and pain and that the method of stimulation accounts for the different sensations.