The Tissues of the Wall of an Artery or Vein

Question

The tissues of the wall of an artery or vein, in order from innermost to outermost, are:
A)smooth muscle, simple squamous epithelium, elastic connective tissue
B)simple squamous epithelium, smooth muscle, fibrous connective tissue
C)fibrous connective tissue, smooth muscle, simple squamous epithelium
D)smooth muscle, fibrous connective tissue, elastic connective tissue

Accepted Answer

The innermost layer of an artery or vein is composed of simple squamous epithelium, referred to as the intima. The next layer is the smooth muscle layer, known as the media, which is responsible for regulating blood flow and maintaining the structural integrity of the vessel. The outermost layer, the adventitia, is composed of fibrous connective tissue and provides support to the vessel. Therefore, the correct order from innermost to outermost layer is simple squamous epithelium, smooth muscle, and fibrous connective tissue. Choice B is the only option that matches this order.