The most rapid nerve impulses are conducted on fibers that are Group of answer choices thick and unmyelinated. thick and myelinated. thin and unmyelinated. of medium thickness with spots of myelin. thin and myelinated.

It is called the medulla oblongata or people usually call it medulla. it is the lower half of the brain stem continuous with the spinal cord. 

The  pelagic  region is divided into three zones. the top zone is the euphotic or sunlit zone. this is the ocean zone that sunlight penetrates. because this zone gets sunlight, photosynthesis can occur and plants can grow here.sub  zones. the oceanic zone is subdivided into the epipelagic,  mesopelagic, and bathypelagic zones. the epipelagic (euphotic) zone, also called the sunlit zone, receives enough sunlight to support photosynthesis.your question does not include multiple choice,but i can give you some info on what the 3 zones hope this : -)