Chap 21 Flashcards
What are the three tunicae of blood vessels?
Tunica intima, Tunica media, Tunica externa
Tunica intima is the inner endothelial layer; Tunica media contains smooth muscle and elastic tissue; Tunica externa is the outer connective tissue.
What is the function of the Tunica intima?
Reduces friction
It is the inner layer of blood vessels.
What is the primary function of the Tunica media?
Controls vasoconstriction/dilation
It is the thickest layer in arteries, containing smooth muscle and elastic tissue.
What is the role of the Tunica externa?
Provides support and protection
It is the outer layer of blood vessels.
What is the primary function of arteries?
Carry blood away from the heart
They have thick walls to handle high pressure.
What do arterioles control?
Blood flow to capillaries
They achieve this via vasoconstriction/dilation.
What is the function of capillaries?
Exchange of gases, nutrients, and wastes with tissues
They are tiny blood vessels that connect arterioles and venules.
What is the role of veins?
Return blood to the heart
They have valves to prevent backflow.
What percentage of total blood volume do veins and venules hold?
~60-70%
They hold the largest volume of blood in the circulatory system.
List three major arteries.
- Aorta (ascending, thoracic, abdominal)
- Pulmonary trunk
- Brachiocephalic trunk
Additional major arteries include right and left common carotids, subclavian, axillary, brachial, radial, and ulnar.
List three major veins.
- Superior vena cava
- Inferior vena cava
- Internal and external jugular veins
Additional major veins include the great saphenous vein and common and internal iliacs.
