Veins

The smallest post-capillary venules resemble large-diameter capillaries. Their thin tunica intima consists of an endothelium and a thin subendothelial layer. No additional tunics are present. Accompanying arterioles are also shown.

The smallest post-capillary venules resemble large-diameter capillaries. Their thin tunica intima consists of an endothelium and a thin subendothelial layer. No additional tunics are present. Accompanying arterioles are also shown.

The smallest post-capillary venules resemble large-diameter capillaries. Their thin tunica intima consists of an endothelium and a thin subendothelial layer. No additional tunics are present. Accompanying arterioles are also shown.

The smallest post-capillary venules resemble large-diameter capillaries. Their thin tunica intima consists of an endothelium and a thin subendothelial layer. No additional tunics are present. Accompanying arterioles are also shown.

The smallest post-capillary venules resemble large-diameter capillaries. Their thin tunica intima consists of an endothelium and a thin subendothelial layer. No additional tunics are present. Accompanying arterioles are also shown.

The smallest post-capillary venules resemble large-diameter capillaries. Their thin tunica intima consists of an endothelium and a thin subendothelial layer. No additional tunics are present. Accompanying arterioles are also shown.

The smallest post-capillary venules resemble large-diameter capillaries. Their thin tunica intima consists of an endothelium and a thin subendothelial layer. No additional tunics are present. Accompanying arterioles are also shown.

As venules enlarge, they transition through muscular venules to become small veins. Compared to arteries, veins are thin-walled vessels with large and irregular lumens. All three tunics are present; a tunica media containing 2-3 layers of smooth muscle and a prominent tunica adventitia. Small veins possess valves that prevent the backflow of blood. An accompanying small artery is also present.

As venules enlarge, they transition through muscular venules to become small veins. Compared to arteries, veins are thin-walled vessels with large and irregular lumens. All three tunics are present; a tunica media containing 2-3 layers of smooth muscle and a prominent tunica adventitia. Small veins possess valves that prevent the backflow of blood. An accompanying small artery is also present.

As venules enlarge, they transition through muscular venules to become small veins. Compared to arteries, veins are thin-walled vessels with large and irregular lumens. All three tunics are present; a tunica media containing 2-3 layers of smooth muscle and a prominent tunica adventitia. Small veins possess valves that prevent the backflow of blood. An accompanying small artery is also present.

As venules enlarge, they transition through muscular venules to become small veins. Compared to arteries, veins are thin-walled vessels with large and irregular lumens. All three tunics are present; a tunica media containing 2-3 layers of smooth muscle and a prominent tunica adventitia. Small veins possess valves that prevent the backflow of blood. An accompanying small artery is also present.

As venules enlarge, they transition through muscular venules to become small veins. Compared to arteries, veins are thin-walled vessels with large and irregular lumens. All three tunics are present; a tunica media containing 2-3 layers of smooth muscle and a prominent tunica adventitia. Small veins possess valves that prevent the backflow of blood. An accompanying small artery is also present.

Medium veins accompany muscular arteries and are often named, e.g. radial vein. Tunica media and tunica adventitia are thicker than in small veins, with the tunica adventitia dominant. Valves, crescent-shaped folds of the tunica intima that project into the lumen, are particularly prominent in medium veins of the lower extremities. Medium veins transition to large veins, such as the jugular vein and vena cavae, that form the major portals for blood return to the heart.

Medium veins accompany muscular arteries and are often named, e.g. radial vein. Tunica media and tunica adventitia are thicker than in small veins, with the tunica adventitia dominant. Valves, crescent-shaped folds of the tunica intima that project into the lumen, are particularly prominent in medium veins of the lower extremities. Medium veins transition to large veins, such as the jugular vein and vena cavae, that form the major portals for blood return to the heart.

Medium veins accompany muscular arteries and are often named, e.g. radial vein. Tunica media and tunica adventitia are thicker than in small veins, with the tunica adventitia dominant. Valves, crescent-shaped folds of the tunica intima that project into the lumen, are particularly prominent in medium veins of the lower extremities. Medium veins transition to large veins, such as the jugular vein and vena cavae, that form the major portals for blood return to the heart.

Medium veins accompany muscular arteries and are often named, e.g. radial vein. Tunica media and tunica adventitia are thicker than in small veins, with the tunica adventitia dominant. Valves, crescent-shaped folds of the tunica intima that project into the lumen, are particularly prominent in medium veins of the lower extremities. Medium veins transition to large veins, such as the jugular vein and vena cavae, that form the major portals for blood return to the heart.

Medium veins accompany muscular arteries and are often named, e.g. radial vein. Tunica media and tunica adventitia are thicker than in small veins, with the tunica adventitia dominant. Valves, crescent-shaped folds of the tunica intima that project into the lumen, are particularly prominent in medium veins of the lower extremities. Medium veins transition to large veins, such as the jugular vein and vena cavae, that form the major portals for blood return to the heart.