The heart is a pumping system which takes in deoxygenated blood through the veins and delivers it to the lungs for oxygenation before pumping it into the various arteries (which provide oxygen and nutrients to body tissues by transporting the blood throughout the body).he cardiovascular system of the head and neck includes the vital arteries that provide oxygenated blood to the brain and organs of the head, including the mouth and eyes. It also includes the veins that return deoxygenated blood from these organs to the heart.
the part of the alimentary canal extending from the pyloric opening of the stomach to the anus. It is a membranous tube, comprising the small intestine and large intestine; called also bowel and gut. See also intestinal tract, and see color plates.
The intestines are a long, continuous tube running from the stomach to the anus. Most absorption of nutrients and water happen in the intestines. The intestines include the small intestine, large intestine, and rectum. The small intestine (small bowel) is about 20 feet long and about an inch in diameter. Its job is to absorb most of the nutrients from what we eat and drink. Velvety tissue lines the small intestine, which is divided into the duodenum, jejunum, and ileum. The large intestine (colon or large bowel) is about 5 feet long and about 3 inches in diameter. The colon absorbs water from wastes, creating stool.