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.
The name Platyhelminthes means flat worms; there are about 15,000 living species. They live in marine and fresh water habitats, moist terrestrial environments, and inside other organisms as parasites. All have. : ectoderm on the outside, endoderm lining the gut, and mesoderm in between.he name Platyhelminthes means flat worms; there are about 15,000 living species. They live in marine and fresh water habitats, moist terrestrial environments, and inside other organisms as parasites. All have. : ectoderm on the outside, endoderm lining the gut, and mesoderm in between.