Library · Histology
Artery histology
Make it clearer
An artery wall is not a single sheet. It is three layers, called tunics, nested concentrically one inside the other, like the rings of a cut tree trunk. Starting at the lumen, the hollow space in the middle, and working outward, you meet the tunica intima first, then the tunica media, and finally the tunica externa, also known as the adventitia.
The middle one, the tunica media, is the layer that carries smooth muscle and elastic fibers, and it is usually the thickest of the three. Cut the artery crosswise and look at that cross section: the tunica media is the wide band in the middle, with the intima inside it and the adventitia outside.
In brief
The wall of an artery is made up of three concentric tunics. From the lumen outward, they are the tunica intima, the tunica media, and the tunica externa, also called the adventitia.
The tunica media contains smooth muscle and elastic fibers and is usually the thickest layer of the arterial wall. In cross section, it forms the middle band between the intima and the adventitia.
Sources (2)
- OpenStax, Rice UniversityAnatomy and Physiology: Chapter 20 ReviewPublished
- OpenStax, Rice UniversityAnatomy and Physiology 2e: Structure and Function of Blood VesselsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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