Alveolar duct

Alveolar duct

Infobox Anatomy
Latin =
GraySubject =
GrayPage =

Caption = Detailed drawing of the alveoli from Gray's Anatomy, 1918 - Schematic longitudinal section of a primary lobule of the lung (anatomical unit);
r. b respiratory bronchiole;
al. d alveolar duct; at atria;
a. s alveolar sac;
'a' alveolus or air cell;
p. a.: pulmonary artery;
p. v pulmonary vein;
l lymphatic;
l. n lymph node.]

Caption2 = Part of a secondary lobule from the depth of a human lung, showing parts of several primary lobules.
1, bronchiole;
2, respiratory bronchiole;
3, alveolar duct;
4, atria;
5, alveolar sac;
6, alveolus or air cell:
m, smooth muscle;
a, branch pulmonary artery;
v, branch pulmonary vein;
s, septum between secondary lobules.
System =
MeshName =
MeshNumber =
DorlandsPre =
DorlandsSuf =

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 distal end. 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 bronchioles exists 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.


External links

* - "Alviolar Duct and Alveolar Sacs"
* - "Respiratory System: lung (sheep), alveolar duct "
* - "Mammal, lung (EM, Medium)"

Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

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

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”