Vessel anatomy
Tends to be smaller and have rigid walls
What are arteries?
Smallest blood vessel that is the site of nutrient, hormone, and gas exchange
What are capillaries?
Network of capillaries delivering blood to tissues; enters by way of proximal metarteriole and departs by distal thoroughfare channel
What are capillary beds?
Carry mostly oxygenated blood away from heart
What are arteries?
Carry mostly deoxygenated blood back to heart
What are veins?
Are larger with less rigid walls and collapse when not filled with blood
What are veins?
regulate blood flow due to contractile capablility and repair damaged vessels
What are pericytes?
blood flows through only one capillary network per circuit from heart
What is simple pathway of circulation?
Largest artery and expands during ventricular systel, recoild in diastole, decreasing fluctuations in bp
What are conducting arteries?
Highly porous, smallest vein, site where most WBCs leave bloodstream
What are venules?
One of three major layers: provides room for small casa vasorum that supply blood to outer half of large vessels
most common capillaries; endothelium forms continuous tube with tight junctions
What are continuous capillaries?
Blood flows through two capillary networks before return to the heart (i.e. hypophyseal portal system)
What is a portal system?
Medium-sized arteries that carry blood to individual organs; smooth muscle makes up wall
What are distributing arteries?
thing tunica media that has much less smooth muscle than in distributing arteries. (i.e. ulnar, radial veins)
What are medium veins?
One of three major layers: secretes chemicals that dilate/constrict vessel; repels platelets to avoid clot formation
What is tunic interna?
Found in organs with rapid absorption or filtration and has filtration pores.
What are fernestrated capillaries?
artery flows directly into vein bypassing capillary bed and reduces heat loss due to cold by shunting blood away from exposed areas
What is a shunt?
smallest major class arteries; control amount of blood delivered to each organ; connected to capillaries by metarterioles
What are arterioles?
distensions of leg veins due to pooling of blood and veins stretch weakening their walls and pulling valve cusps apart
What are varicose veins?
One of three major layers: strengthens vessel to prevent bp from rupturing it
What is tunica media?
Allow large proteins or while blood cells move to bloodstream; endothelial cells widely spaced from each other
What are sinusoids?
pulmonary arteries enter each lung and pulmonary veins (2 per lung) depart lungs
What is pulmonary cirucluation?
A bulging sac in arterial wall that puts pressure on brain tissue, nerves or vessels due to hypertension and/or atherosclerosis
What is an aneurysm?
Largest class of veins that has more smooth muscle than in other veins (i.e. venae cavae, pulmonary veins)
What are large veins?