Dissection occurs when blood separates the laminar planes of which arterial wall layer?

Dissection occurs when blood separates the laminar planes of which arterial wall layer?

• A. Intima
• B. Media
• C. Adventitia
• D. Endothelium

Answer: (B)

Dissection happens when blood splits the wall along its natural laminar planes, and those planes are in the media—the middle layer of the artery. The media is built of concentric elastic lamellae and smooth muscle, arranged like sheets that can be separated under pressure or by a tear allowing blood to invade. When this separation occurs, a false lumen forms within the medial layer as blood tracks between the lamellae. The endothelium (inner lining) is not where these laminar planes separate, and the adventitia (outer layer) is outside the laminae of the media. So the dissection plane resides in the media.

Dissection happens when blood splits the wall along its natural laminar planes, and those planes are in the media—the middle layer of the artery. The media is built of concentric elastic lamellae and smooth muscle, arranged like sheets that can be separated under pressure or by a tear allowing blood to invade. When this separation occurs, a false lumen forms within the medial layer as blood tracks between the lamellae. The endothelium (inner lining) is not where these laminar planes separate, and the adventitia (outer layer) is outside the laminae of the media. So the dissection plane resides in the media.