Types
These vessels carry blood away from the heart.
What are arteries?
The inner layer of blood vessels.
What is tunica intima?
Blood flow depends on these two main factors.
What are pressure and resistance?
The least permeable capillaries.
What are continuous capillaries?
Narrowing of blood vessels.
What is vasoconstriction?
These vessels return blood to the heart.
What are veins?
The middle smooth muscle layer.
What is tunica media?
The force exerted by blood on vessel walls.
What is blood pressure?
Capillaries with pores for filtration.
What are fenestrated capillaries?
Widening of blood vessels.
What is vasodilation?
These vessels allow exchange of gases and nutrients.
What are capillaries?
The outer connective tissue layer.
What is tunica externa?
The amount of blood moving through a vessel per time.
What is blood flow?
The most permeable capillaries.
What are sinusoidal capillaries?
Portal systems connect these structures.
What are two capillary beds?
These small arteries regulate blood flow into capillaries.
What are arterioles?
All blood vessels are lined with this type of epithelium.
What is simple squamous epithelium?
Smaller vessel diameter causes this change.
What is increased resistance?
The site where exchange occurs between blood and tissues.
What is the capillary bed?
Blood supply to tissues.
What is perfusion?
These small veins collect blood from capillaries.
What are venules?
This layer controls vasoconstriction and vasodilation.
What is tunica media?
Higher viscosity causes this effect on resistance.
What is increased resistance?
This structure directly connects an arteriole to a venule.
What is a metarteriole?
Alternate route for blood flow.
What is an anastomosis?