A.   open when the tissue needs nutrients, control blood flow into the true capillaries, close when the tissue's needs have been met, and cause blood to flow directly from the metarteriole into the postcapillary venule.

B.   control blood flow into the true capillaries.

C.   cause blood to flow directly from the metarteriole into the postcapillary venule.

D.   open when the tissue needs nutrients.

E.   close when the tissue's needs have been met.

A.   allow for diffusion of nutrients to the tissues.

B.   allow for diffusion of nutrients and metabolic wastes.

C.   drain the capillary bed.

D.   supply metarteriole with blood.

E.   allow for diffusion of metabolic wastes from the tissues.

A.   is a momentary chemical control of local blood flow.

B.   allows for an increase in the perfusion of a local tissue.

C.   involves muscular constriction of arterioles to alter local perfusion.

D.   involves building new muscle tissue and decreasing the amount of blood vessels in a region.

A.   the high amount of water in the blood, and it promotes diffusion out of the capillaries.

B.   the proteins in the blood, and it promotes reabsorption.

C.   the pressure generated by the heart, and it favors osmosis into the arteriole end of the capillary bed.

D.   the high amount of water in the blood, and it promotes filtration from arterioles.

E.   the proteins in the blood, and it promotes filtration.

A.   below normal.

B.   above normal.

A.   an increase in the relative amount of smooth muscle and a decrease in the relative amount of elastic fibers.

B.   an increase in relative amounts of smooth muscle and elastic fibers and a decrease in endothelium.

C.   a decrease in both smooth muscle and elastic fibers and an increase in areolar connective tissue.

D.   a decrease in the relative amount of smooth muscle and an increase in the relative amount of elastic fibers.

A.   are found only in the largest veins.

B.   are formed of the tunica media.

C.   make the use of a skeletal muscle pump unnecessary for venous blood flow.

D.   cause venous blood flow to go in only one direction.

E.   are the leading cause of high blood pressure.

A.   includes a functional end artery that makes an arterial anastomosis.

B.   is one in which circulation to a large organ involves only one artery and one main (portal) vein.

C.   is a simple circulatory system with an arteriovenous anastomosis.

D.   is one in which blood flows through two capillary beds before being sent back to the heart.

E.   is one in which multiple arteries converge on one organ or body region.

A.   Pulmonary veins

B.   Pulmonary arteries

C.   Systemic veins

D.   Systemic arteries

A.   Buildup of carbon dioxide and hydrogen ions will cause vasodilation.

B.   Buildup of carbon dioxide and hydrogen ions will cause vasoconstriction.

C.   Increases in oxygen and potassium will cause vasodilation.

D.   Decreases in oxygen and potassium will cause vasoconstriction.

E.   Decreases in carbon dioxide and hydrogen ions will cause vasodilation.

A.   regression of blood vessels in adipose tissue and angiogenesis in skeletal muscle.

B.   angiogenesis in adipose tissue and regression of blood vessels in skeletal muscle.

C.   angiogenesis in both adipose tissue and skeletal muscle.

D.   regression of blood vessels in both adipose tissue and skeletal muscle.

E.   changes in the diameter of blood vessels, but no angiogenesis nor regression.

A.   Filtration is driven by concentration gradients, whereas reabsorption depends on hydrostatic pressure.

B.   Filtration happens at the venule end of a capillary bed and reabsorption happens in feeder arterioles.

C.   Filtration involves bulk flow of fluid out of the blood, whereas reabsorption is bulk flow back into the blood.

D.   The direction of filtration can be either into or out of the blood, but reabsorption always involves fluids entering the blood.

A.   a high degree of vascularization, therefore high perfusion and rapid healing.

B.   a low degree of vascularization, therefore low perfusion and slow healing.

C.   a high degree of vascularization, therefore low perfusion and slow healing.

D.   a high degree of vascularization, therefore high perfusion and slow healing.

E.   a low degree of vascularization, therefore high perfusion and rapid healing.

A.   show no change in their lumen size.

B.   get larger.

C.   get smaller.

A.   exocytosis and endocytosis by endothelial cells.

B.   diffusion from areas of higher concentration to lower concentration.

C.   active transport (using ATP) by protein carriers of endothelial cells.

D.   pinocytosis using fluid-filled vesicles.