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

D.   open when the tissue needs nutrients.

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

A.   supply metarteriole with blood.

B.   allow for diffusion of nutrients to the tissues.

C.   drain the capillary bed.

D.   allow for diffusion of nutrients and metabolic wastes.

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

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

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

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

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

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

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

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

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

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

A.   above normal.

B.   below normal.

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

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

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

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

A.   are the leading cause of high blood pressure.

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

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

D.   are formed of the tunica media.

E.   are found only in the largest veins.

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

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

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

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

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

A.   Pulmonary veins

B.   Pulmonary arteries

C.   Systemic arteries

D.   Systemic veins

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

B.   Increases in oxygen and potassium will cause vasodilation.

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

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

E.   Decreases in oxygen and potassium will cause vasoconstriction.

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

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

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

D.   angiogenesis in both adipose tissue and skeletal muscle.

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

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

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

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

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 high perfusion and slow healing.

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

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

A.   get smaller.

B.   show no change in their lumen size.

C.   get larger.

A.   exocytosis and endocytosis by endothelial cells.

B.   pinocytosis using fluid-filled vesicles.

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

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