###### Created: 2024-01-13 14:31 ###### Areas & Topics: #medicine #anatomy ###### Note Type: #permanent ###### Connected to: [[Systemic Arterial Blood Pressure - Medical Sciences, Third Edition]] - Arteries are the system of large, high pressure blood vessels that carry oxygenated blood away from the heart and around the body. - The exception to this is the pulmonary arteries which carry deoxygenated blood from the right side of the heart to the lungs. ### Structure **Tunica Externa (Tunica Adventitia)** - The tunica externa (also known as the tunica adventitia) is the outermost layer of arteries. - It is the outer connective tissue sheath of arteries, mainly made up of collagen and elastic fibres. - Since it is furthest from the blood flowing within the artery, small blood vessels known as vasa vasorum supply the adventitia and the outer part of the tunica media with their blood. **Tunica Media** - The tunica media is the middle layer of arteries which is primarily made up of smooth muscle cells, collagen and elastic fibres. **Tunica Intima** - The tunica intima is the innermost layer of arteries and is made up of endothelial cells which are in direct contact with the blood flowing through the artery. - Since the cells of the tunica intima are in direct contact with the blood flowing through them they don't require additional vessels to supply them. ![[Pasted image 20240113142412.png]]