Capillaries definitions Flashcards

Smallest blood vessels, 5-10 micrometers in diameter, facilitating nutrient and gas exchange between blood and tissues.

The only layer in capillary walls, consisting of endothelium and a basement membrane, allowing for efficient exchange.

Red blood cells, about 7.5 micrometers in diameter, often travel single file through capillaries.

Networks of branched capillaries facilitating microcirculation, fed by arterioles and drained by venules.

Most common type, least permeable, with tight junctions and small intercellular clefts.

Capillaries with small pores, moderate permeability, found in kidneys and endocrine glands.

Most permeable capillaries with large holes, found in liver and bone marrow, allowing large molecules to pass.

Blood flow through capillary beds from terminal arterioles to postcapillary venules.

Structure in mesenteric capillary beds allowing blood to bypass capillaries, consisting of metarteriole and thoroughfare channel.

Transitional vessel with precapillary sphincters, part of the vascular shunt controlling blood flow.

Continuation of metarteriole without smooth muscle, connecting to postcapillary venule.

Smooth muscle rings controlling blood flow into capillary beds, part of metarterioles.

Small arteries regulating blood flow to capillary beds through vasoconstriction.

Smallest venules receiving blood from capillary beds, beginning the return to the heart.

Inner lining of capillaries, forming a barrier for exchange of substances between blood and tissues.