Which evidence from the sea floor shows that tectonic plates move ? a) The sea floor is much older than any of the continents. b) The sea floor is youngest near a mid-ocean ridge and older farther away. c) Mid-Ocean ridges circle Eqarth like seams in a baseball d) The sea floor is thinner than continental crust.
The trachea, colloquially called the windpipe, is a tube that connects the pharynx and larynx to the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs.he trachea is lined with a layer of pseudostratified columnar epithelium, a type of epithelium. The epithelium contains goblet cells, which are glandular, modified simple columnar epithelial cells that produce mucins, the main component of mucus. Mucus helps to moisten and protect the airways.
The walls of the trachea are composed of connective tissue and smooth muscle. A number of C-shaped rings of cartilage, usually between 15 and 20, are contained in the tracheal wall. The C shape is open to the rear of the windpipe due to its nearness to the esophagus. This allows the esophagus to expand toward the front of the throat when food passes through it. The rings of cartilage also keep the trachea from collapsing due changes in air pressure that normally occur during respiration.