patho notes chp10
Blood Vessels and Their Structure
- Venules lead to larger veins
- Definition: A vein is a blood vessel that drains blood back to the heart.
- Structure of blood vessels:
- Each artery or vein consists of three layers:
- Tunica intima: Inner layer made of simple squamous epithelium (endothelium).
- Tunica media: Middle layer made of smooth muscle that facilitates the pulsation of blood flow.
- Tunica externa: Outermost layer made of connective tissue.
- Each artery or vein consists of three layers:
- Capillaries:
- Structure: Composed only of the tunica intima, allowing for efficient gas exchange due to their thin walls.
- Made of basement membrane and simple squamous epithelium.