upper respiratory tracts
51skeletal system, human — ▪ anatomy Introduction the internal skeleton that serves as a framework for the body. This framework consists of many individual bones (bone) and cartilages (cartilage). There also are bands of fibrous connective tissue the ligaments (ligament)… …
52Africa — /af ri keuh/, n. 1. a continent S of Europe and between the Atlantic and Indian oceans. 551,000,000; ab. 11,700,000 sq. mi. (30,303,000 sq. km). adj. 2. African. * * * I Second largest continent on Earth. It is bounded by the Mediterranean Sea,… …
53digestive system, human — Introduction the system used in the human body for the process of digestion. The human digestive system consists primarily of the digestive tract (alimentary canal), or the series of structures and organs through which food and liquids pass… …
54bivalve — bivalvular /buy val vyeuh leuhr/, adj. /buy valv /, n. 1. Also called lamellibranch. Zool. any mollusk, as the oyster, clam, scallop, or mussel, of the class Bivalvia, having two shells hinged together, a soft body, and lamellate gills. adj. 2.… …
55cañada — /keuhn yah deuh, yad euh/, n. Chiefly Western U.S. 1. a dry riverbed. 2. a small, deep canyon. [1840 50; < Sp, equiv. to cañ(a) CANE + ada n. suffix] * * * Canada Introduction Canada Background: A land of vast distances and rich natural resources …
56Canada — /kan euh deuh/, n. a nation in N North America: a member of the Commonwealth of Nations. 29,123,194; 3,690,410 sq. mi. (9,558,160 sq. km). Cap.: Ottawa. * * * Canada Introduction Canada Background: A land of vast distances and rich natural… …
57Head and neck anatomy — focuses on the structures of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat. It is an area frequently studied in depth by surgeons, dentists, dental… …
58echinoderm — /i kuy neuh derrm , ek euh neuh /, n. any marine animal of the invertebrate phylum Echinodermata, having a radiating arrangement of parts and a body wall stiffened by calcareous pieces that may protrude as spines and including the starfishes, sea …
59Brain stem — Infobox Brain Name = Brain stem Latin = truncus encephali GraySubject = 187 Caption = Hind and mid brains; postero lateral view. IsPartOf = Brain Components = Medulla, Pons, Midbrain Artery = Vein = BrainInfoType = ancil BrainInfoNumber = 218… …
60reptile — reptilelike, adj. reptiloid /rep tl oyd /, adj. /rep til, tuyl/, n. 1. any cold blooded vertebrate of the class Reptilia, comprising the turtles, snakes, lizards, crocodilians, amphisbaenians, tuatara, and various extinct members including the… …
