How many tunics make up a vessel wall?

1. They are named from innermost outward. 2. Intima, media and externa. 3. From the most interior layer to the outer, these tunics are the tunica intima, media and externa. 4. So the answer is three. _Source: OpenStax 'Anatomy and Physiology 2e', Ch 20 'The Cardiovascular System: Blood Vessels and Circulation'_