Name = PAGENAME
Caption = Detailed drawing of the alveoli from
Gray's Anatomy, 1918 - Schematic longitudinal section of a primary lobuleof the lung(anatomical unit);
al. d alveolar duct; at atria;
'a' alveolus or air cell;
Caption2 = Part of a secondary lobule from the depth of a human
lung, showing parts of several primary lobules.
2, respiratory bronchiole;
3, alveolar duct;
alveolusor air cell:
septumbetween secondary lobules.
Alveolar ducts are the tiny end ducts of the branching airways that fill the
lungs. Each lung holds approximately 1.5 to 2 million of them. The tubules divide into two or three alveolar sacs at the distalend. They are formed from the confluence openings of several alveoli. Distal terminations of alveolar ducts are atria which then end in alveolar sacs.
In human anatomy, respiratory
bronchiolesexists proximal to the alveolar ducts. The epithelial lining consists of smooth muscle knobs covered by nonciliated, simple cuboidal cells. The smooth muscle constricts under parasympathetic innervation and relax under sympathetic innervation.
* - "Alviolar Duct and Alveolar Sacs"
* - "Respiratory System: lung (sheep), alveolar duct "
* - "Mammal, lung (EM, Medium)"
Wikimedia Foundation. 2010.
Look at other dictionaries:
alveolar duct emphysema — distention of the alveolar ducts as seen in elderly individuals, often producing little or no functional disturbance … Medical dictionary
Alveolar gland — Section of pancreas of dog. X 250 … Wikipedia
Duct (anatomy) — For qualities of writing or speech, see Ductus (linguistics). Duct Dissection of a lactating breast. 1 Fat 2 Lactiferous duct/lobule 3 Lobule 4 Con … Wikipedia
duct — A tubular structure giving exit to the secretion of a gland or organ, capable of conducting fluid. SEE ALSO: canal. SYN: ductus [TA]. [L. duco, pp. ductus, to lead] aberrant ducts SYN: aberrant ductules, under ductule … Medical dictionary
Nasopalatine duct cyst — The nasopalatine duct cyst (abbreviated NPDC) occurs in the median of the palate, usually anterior to first molars. Radiographically, it may often appear as a heart shaped radiolucency. It is usually asymptomatic, but may sometimes produce an… … Wikipedia
Median alveolar cyst — The median alveolar cyst is a rare cyst, occurring in the bony alveolus between the maxillary central incisors. It is distinguished from a periapical cyst by the fact that adjacent teeth are vital. Treatment Treatment is by enucleation, or… … Wikipedia
sac — 1. A pouch or bursa. SYN: saccus [TA]. SEE ALSO: sacculus. 2. An encysted abscess at the root of a tooth. 3. The capsule of a tumor, or envelope of a cyst. [L. saccus, a … Medical dictionary
alveolus — A small cell, cavity, or socket. 1. SYN: pulmonary a.. 2. One of the terminal secretory portions of an alveolar or racemose gland. 3. One of the honeycomb pits in the wall of the stomach. 4. SYN … Medical dictionary
Bronchus — Infobox Anatomy Name = Bronchus Latin = GraySubject = 237 GrayPage = 1084 Caption = Conducting passages. Caption2 = Front view of cartilages of larynx, trachea, and bronchi. Precursor = System = respiratory Artery = bronchial artery Vein =… … Wikipedia
Respiratory system — See also: Respiratory tract Respiratory A complete, schematic view of the human respiratory system with their parts and functions. Latin … Wikipedia