Diagram of the layers within Earth's atmosphere. Troposphere. The troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense.Almost all weather is in this region. Stratosphere. The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high.he troposphere starts at the Earth's surface and extends 8 to 14.5 kilometers high (5 to 9 miles). This part of the atmosphere is the most dense. Almost all weather is in this region.
conus. n, pl-ni. 1. (Anatomy) anatomy zoology any of several cone-shaped structures, such as the conus medullaris, the lower end of the spinal cord. 2. (Zoology) anatomy zoology any of several cone-shaped structures, such as the conus medullaris, the lower end of the spinal cord. continental United States.
The fibrous extension of the cord, the filum terminale, is a nonneural element that extends down to the coccyx. The cauda equina (CE) is a bundle of intradural nerve roots at the end of the spinal cord, in the subarachnoid space distal to the conus medullaris.Cauda is Latin for tail, and equina is Latin for horse (ie, the horse's tail).he fibrous extension of the cord, the filum terminale, is a nonneural element that extends down to the coccyx. The cauda equina (CE) is a bundle of intradural nerve roots at the end of the spinal cord, in the subarachnoid space distal to the conus medullaris.