Arteries: Function, Anatomy, And Types

Arteries: Function, Anatomy, And Types

Briefly describe the histological features of an elastic artery (large artery).
Answer:

Elastic Artery Histological features

The characteristic histological features of an elastic artery (syn, large-sized artery) are as follows:

Tunica intima

• The subendothelial layer is prominent.
• Internal elastic lamina is not visible.

Tunica media

• A large number of elastic fibres are arranged in the form of concentric and fenestrated laminae or sheets.
• The concentric layers of smooth muscle fibres in between the elastic lamellae.

Tunica adventitia

• Thin and made up of connective tissue. It contains longitudinally running collagen fibres, which merge with external elastic lamina.
• Contains vasa vasorum.

Elastic Artery Functions

• Conduct blood from the heart to medium-sized (muscular) arteries.
• Elastic recoil of the vessel wall ensures continuous flow of the blood through medium-sized arteries.

Elastic Artery Examples

• Aorta
• Pulmonary trunk
• Main branches of the aorta
  • Brachiocephalic trunk
  • Common carotid artery
  • Left subclavian artery

Three Layers/Coats In The Wall Of The Artery

The three layers/coats in the wall of an artery from inside to outside are as follows:

• Tunica intima
• Tunica media
• Tunica adventitia

The features of these coats are given in Table.

Features of Three Coats in the Wall of Artery

 Histological Features of an Arteriole

The arterioles are small arteries with diameter <0.5 mm.

Arteriole Histological features

• Tunica intima Consists of the only endothelial lining (the subendothelial layer and internal elastic laminae are absent).
• Tunica media is Made up of one to five layers of smooth muscle fibres.
• Tunica adventitia is Thin and poorly developed.