Open main menu

Wikipedia β

In anatomy and physiology, a duct is a circumscribed channel leading from an exocrine gland or organ.

Duct
Dissected lactating breast gray1172.png
Dissection of a lactating breast.
1 - Fat
2 - Lactiferous duct/lobule
3 - Lobule
4 - Connective tissue
5 - Sinus of lactiferous duct
6 - Lactiferous duct
Gray1033.png
Section of the human esophagus. Moderately magnified. The section is transverse and from near the middle of the gullet.
a. Fibrous covering.
b. Divided fibers of longitudinal muscular coat.
c. Transverse muscular fibers.
d. Submucous or areolar layer.
e. Muscularis mucosae.
f. Mucous membrane, with vessels and part of a lymphoid nodule.
g. Stratified epithelial lining.
h. Mucous gland.
i. Gland duct.
m’. Striated muscular fibers cut across.
Identifiers
FMA 30320
Anatomical terminology

Contents

Types of ductsEdit

Duct systemEdit

As ducts travel from the acinus which generates the fluid to the target, the ducts become larger and the epithelium becomes thicker. The parts of the system are classified as follows:

Type of duct Epithelium Surroundings
intralobular duct simple cuboidal parenchyma
interlobular duct simple columnar connective tissue
interlobar duct stratified columnar connective tissue

Some sources consider "lobar" ducts to be the same as "interlobar ducts", while others consider lobar ducts to be larger and more distal from the acinus. For sources that make the distinction, the interlobar ducts are more likely to classified with simple columnar epithelium (or pseudostratified epithelium), reserving the stratified columnar for the lobar ducts.

See alsoEdit

External linksEdit