Structure of a vein, which consists of three main layers: an outer layer of connective tissue, a middle layer of smooth muscle, and an inner layer lined with endothelium. A vein (/ veɪn /) is a …

The meaning of VEIN is blood vessel; especially : any of the tubular branching vessels that carry blood from the capillaries toward the heart. How to use vein in a sentence.

Jun 19, 2022 · The other purpose is to carry oxygen-rich blood from your lungs to your heart. This is the only time veins carry oxygen-rich blood. The purpose of each vein depends upon where …

Vein, in human physiology, any of the vessels that, with four exceptions, carry oxygen-depleted blood to the right upper chamber (atrium) of the heart. The four exceptions—the pulmonary …

Sep 13, 2024 · Veins are divided into four types: pulmonary, systemic, superficial, and deep veins. Veins have three layers: an outer, middle, and inner layer that help them transport blood …

a vessel through which blood passes from various organs or parts back to the heart, in the systemic circulation carrying blood that has given up most of its oxygen.

Aug 3, 2023 · Veins are the blood vessels that collect the deoxygenated blood from the various tissues and organs of the body and transport it back to the heart. The blood vessels that carry …