Medical dictionary. 2011.
terminal saccular phase — see under period … Medical dictionary
alveolar period — the period or phase in lung development beginning in utero after the terminal saccular period (about 32 to 36 weeks) and lasting until about eight years of age. The terminal alveolar saccules subdivide several more times and mature alveoli form.… … Medical dictionary
canalicular period — the period or phase of prenatal lung development lasting in different parts of the lungs from the sixteenth or seventeenth week to the twenty sixth week or later, and followed by the terminal saccular period. Basic structures of the gas… … Medical dictionary
Development of human lung — The development of human lung arises from the laryngotracheal groove. The larynx, trachea, bronchi and lungs begin to form during the fourth week of embryonic development.[1] At this time, the respiratory diverticulum (lung bud) appears ventrally … Wikipedia
reproductive system, animal — Introduction any of the organ systems by which animals reproduce. The role of reproduction is to provide for the continued existence of a species; it is the process by which living organisms duplicate themselves. Animals compete with… … Universalium
cephalopod — /sef euh leuh pod /, n. 1. any mollusk of the class Cephalopoda, having tentacles attached to the head, including the cuttlefish, squid, and octopus. adj. 2. Also, cephalopodic, cephalopodous /sef euh lop euh deuhs/. belonging or pertaining to… … Universalium
sound reception — Introduction response of an organism s aural mechanism, the ear, to a specific form of energy change, or sound waves. Sound waves can be transmitted through gases, liquids, or solids, but the hearing function of each species is particularly … Universalium
respiration, human — ▪ physiology Introduction the process by which oxygen is taken up and carbon dioxide discharged. The design of the respiratory system The human gas exchanging organ, the lung, is located in the thorax, where its delicate tissues are… … Universalium
perciform — ▪ fish order Introduction any member of the order Perciformes, a group of bony fishes with more than 6,000 species placed in about 150 families. The order is the largest group of fishes in the world today. Perciform fishes occur in… … Universalium
