each of the pair of organs situated within the rib cage, consisting of elastic sacs with branching passages into which air is drawn, so that oxygen can pass into the blood and carbon dioxide be removed. Lungs are characteristic of vertebrates other than fish, though similar structures are present in some other animal groups.
/ ləngd/ adj. [in comb.]
/ -ˌfoŏl/ n.
The respiratory organ
of air-breathing vertebrates. A pair of lungs is situated in the thorax, within the ribcage. Each consists essentially of a thin moist membrane that is folded to increase its surface area. Exchange of oxygen and carbon dioxide
takes place between blood capillaries on one side of the membrane and air on the other. The lung is supplied with air through a bronchus
. In mammals and reptiles the membrane of the lung takes the form of numerous sacs (see alveolus
) that are connected to the bronchus via bronchioles
(see illustration). The lungs themselves contain no muscular tissue and are ventilated by respiratory movements
, the mechanisms of which vary with the species.
In terrestrial Mollusca
, a highly vascular part of the mantle
involved in respiration. 2.
In air-breathing vertebrates, the respiratory organ. It is probably derived from an accessory respiratory organ
of aquatic vertebrates inhabiting oxygen-depleted fresh water: this developed into the swim-bladder
of many fish. The lung is present embryonically as a diverticulum of the gut. It contains many alveoli
across whose walls oxygen and carbon dioxide
lung (lung) n.
one of the pair of organs of respiration, situated in the chest cavity on either side of the heart. The lungs communicate with the atmosphere through the trachea, which opens into the pharynx. The trachea divides into two bronchi, which enter the lungs and branch into bronchioles. These divide further and terminate in minute air sacs (alveoli), the sites of gaseous exchange. (See illustrations.) Atmospheric oxygen is absorbed and carbon dioxide
from the blood of the pulmonary capillaries is released into the lungs (see (pulmonary) circulation
(Chin., ‘dragon’). In Taoism
, the dragon represents the yang
principle, and is thus often portrayed accompanied by representations of yin
—e.g. clouds or water. Dragons have important active roles in ruling and guarding the world. See also DRAGONS, CHINESE
= MLG. lunge
, MDu. longe
), OHG. lungun
), corr. to ON. lunga
; f. Gmc. *luŋg-
:- IE. *lṇgwh-
; see LIGHT2
. The lungs were so named because of their lightness; cf. LIGHTS
, bung, clung, dung, flung, hung, lung, outflung, rung, shantung, slung, sprung, strung, stung, sung, swung, tongue, underslung, wrung, young
•aqualung • hamstrung • ox tongue