Custom Search

Cardiovascular System:

Cardiovascular System Index


Blood Cells

Blood Vessel Anatomy


Cardiovascular System Overview

Circulatory System


Fetal Circulation

Heart Overview

Heart Chambers, Valves and Blood Flow

Heart Muscles

Liver and the Hepatic System

Lymphatic System

Monitor (Heart Monitor)

Pulse or Heart Rate



Thoracic Cage



Cardiovascular System Video Index

Human Body Index

Human Body Video Index

Science Videos

Science Main Index


The veins are blood vessels that carry blood towards the heart. They are part of the cardiovascular system, along with the heart, arteries and capillaries. Read on to learn more about the veins, and what they do.

On this page:


Top of Page

Adbomenal Vasculature
Abdominal Vascular System -Anterior View

Veins are part of the circulatory system, along with the heart, arteries and capillaries. Veins are blood vessels that carry blood to the heart. Most veins carry deoxygenated blood from the tissues back to the heart. However, the pulmonary vein and the umbilical vein carry oxygenated blood. The pulmonary vein is carrying blood from the lungs to the heart, and is therefore carrying oxygenated blood.

Once oxygenated blood from the arteries delivers oxygen and nutrients to cells via the capillaries, the now deoxygenated blood enters the venules. Venules converge into larger veins as they collect more blood to be returned to the heart.

Veins differ from arteries in two significant ways. Veins operate at a lower blood pressure, since the blood has lost considerable pressure traveling through the arteries and capillaries. Therefore, veins are less muscular than arteries. Also, many veins must transport blood from the lower body up to the heart. This requires the blood to flow against gravity. To facilitate this upward flow, many veins have one-way valves that prevent blood from flowing back and pooling in the lower extremities.


Books on the Veins

Top of Page



Other links on the Veins

Top of Page


Top of Page


Copyright © 1998-2012 Kidport