1 The kidneys are used to remove excess water and ions from the blood. 2  These are then expelled as urine. 3  The kidneys perform a vital role in homeostatic regulation in mammals, removing excess water, salt, and urea from the blood.
Ectoparasites Parasites that live on the outside of the host, either on the skin or the outgrowths of the skin, are called ectoparasites. They are directly transmitted between hosts.
Definition of posit for English Language Learners. : to suggest (something, such as an idea or theory) especially in order to start a discussion. See words that rhyme with posit Nglish: Translation of posit for Spanish speakers Britannica English: Translation of posit for Arabic speakers.