Internal elastic lamina

Internal Elastic Lamina

The Internal Elastic Lamina (IEL) is a key structural component of the arterial wall. It is a thin layer of elastic fibers that separates the tunica intima from the tunica media, two of the three layers that make up the wall of an artery.

File:Internal Elastic Lamina.jpg

Micrograph showing the internal elastic lamina (IEL) in a small artery. Source: Wikimedia Commons

Structure

The IEL is primarily composed of elastin, a highly elastic protein that allows the artery to stretch and recoil without damage. This layer is typically fenestrated, meaning it has numerous small openings or windows. These fenestrations allow for the passage of nutrients and waste products between the tunica intima and tunica media.

Function

The primary function of the IEL is to provide structural support to the artery, maintaining its shape and integrity even under high pressure. The elasticity of the IEL also allows the artery to expand and contract with each heartbeat, helping to regulate blood flow and pressure.

Clinical Significance

Damage to the IEL can lead to a variety of cardiovascular diseases. For example, in atherosclerosis, the IEL can become thickened and lose its elasticity, leading to narrowing of the artery and reduced blood flow. Similarly, in aneurysm, a weak or damaged IEL can lead to bulging of the artery wall.

See Also

• Artery
• Elastin
• Atherosclerosis
• Aneurysm