GOV.WALES uses cookies which are essential for the site to work. Non-essential cookies are also used to tailor and improve services. By continuing to use this site, you agree to our use of cookies.
Definition: Tiwb (efallai â dyfais gysylltiedig) er mwyn draenio hylif o un rhan o’r corff i ran arall, gan amlaf i ddraenio hylif cerebrosbinol o’r ymennydd i geudod arall yn y corff.
