Doppler ultrasound is a type of ultrasound that depends on the Doppler Effect, a change in the wave's frequency, which can occur from the motion of a reflector, such a red blood cell. We experience the Doppler Effect when, for example, an ambulance approaches us, passes and then drives away.
Definition of PLACODERM. : any of a class (Placodermi) of extinct chiefly Devonian fishes with an armor of bony plates and primitive jaw structures.ADVERTISEMENT. New Latin Placodermi, ultimately from GK plak-, plax + derma skin â more at derm-. any of a class (Placodermi) of extinct chiefly Devonian fishes with an armor of bony plates and primitive jaw structures. ADVERTISEMENT.
Taxonomy and evolution. Etymology. Its generic name, Amblyrhynchus, is a combination of two Greek words, Ambly- from Amblus (á¼Î¼Î²Î»Ï) meaning blunt and rhynchus (ÏÏÎ³ÏÎ¿Ï) meaning snout. Its specific name is the Latin word cristatus meaning crested, and refers to the low crest of spines along the animal's back.