专业术语—口腔生理学术语R1(英文详解)（在线收听）

    Rest Position - a position the jaw adopts when at rest with the lips lightly together.

    Reticular fibres - are fine type III collagen fibres forming a net-like supporting framework or reticulum. They are found around small blood vessels, nerve cells, muscle fibres and in particular beneath epithelial membranes as part of thebasal lamina.

    Reticular formation - in the central core of the medulla, it consists of several structures, including the periaquaductal grey. The reticular formation integrates information from many sources and influences sensory motor and autonomic activity. It is involved in aversive drive (behaviour which is an instinctive turning away from the unpleasant).

    Retinoic acid - a product of retinol(Vitamin A) which binds onto cell membranes and controls cell division and differentiation through gene expression.

    Ribosomes - - structures in the cy lasm of cells which attach onto messenger RNA. At the ribosome, the code of nucleotides on the mRNA is translated into a series of aminoacids.

    RNA - Ribosenucleic acid - seenucleic acids.

    Root resorption - resorption of cementum and underlying root dentine by osteoclasts. Temporary zones of root resorption may occur during orthodontic tooth repositioning. More extensive and irreversible root resorption may occur if the root becomes ankylosed.

    Rugae - raised ridges of epithelium, each with its core of lamina propria, found on the anterior wall of the hard palate.