Question

multiple choice question
what is the tunica interna?
the middle layer of a blood vessel walls composed of smooth muscle
the inner lining of a blood vessels wall composed of simple squamous epithelium
the branching of vessels observed in the heart
the outermost layer of a blood vessel walls composed of loose connective tissue

Explanation:

The tunica interna is the innermost layer of a blood - vessel wall and is composed of simple squamous epithelium.

Answer:

The inner lining of a blood vessel's wall composed of simple squamous epithelium