Blood Vessels Flashcards
Arteries
Structure: tunica intima, tunica media, tunica adventitia
Arteries
Structure
- small arteries connected to capillaries are called arterioles
- large arteries and arterioles have thick walls containing much smooth muscle and elastic conn. tissue fibers
Arteries
Tunica intima
- inner layer
- composed of squamous epithelial, thin conn. tissue, elastic membrane
Arteries
Tunica media
- middle layer
- composed of thick layer of smooth muscle with many elastic fibers
Arteries
Tunica adventitia
- outer layer
- composed of fibrous conn. tissue
Arteries
Functions
- designed to expand and contract a blood flow changes
- the many elastic fibers are responsible for their expandable properties
Veins
Structure: tunica intima, tunica media, tunica adventitia
Veins
Structure
-larger veins have 3 tissue layer with much less smooth muscle and elastic fibers
Veins
Tunica intima
- inner layer
- contains a thin endothelial layer and thin elastic membrane
Veins
Tunica media
- middle layer
- thin layer containing some smooth muscle and a few elastic fibers
Veins
Tunica adventitia
- outer layer
- composed of fibrous conn. tissue an covers the outside of the vessels
Veins
Functions
- designed to collect blood under low pressure (they do not need much elastic tissue)
- contain valves that aid in the process of blood flow back to the heart
- storage reservoirs for blood
Capillaries
Structure
- small, thin walled vessels
- walls are composed of squamous epithelium and a thin layer of conn. tissue
Capillaries
Functions
- form connections between arteries and veins, making up large networks within body organs
- thin walls allow nutrients to diffuse out of blood and into organs
- rate of blood flow is very low which allows time for the exchange of nutrients
