The Heart

The heart is a pumping system which intakes deoxygenated blood through the veins, delivering it to the lungs for oxygenation and then pumping it into the various arteries to be transmitted to where it is needed throughout the body for energy. The heart is about the size of a fist but delivers a more powerful punch. Luckily for us, it contains a buffer zone to decrease its force or we would be shaken by every beat. This buffer zone also protects the heart from outside injury and keeps it from scraping against the chest wall. In some instances, nightmares can seem so real that the heart will pound in fear. In one study, the heart rate of the sleeper was timed at 150 beats per minute. Myth has it that the heart is the seat of the emotions, but it is, instead, a pump to circulate the blood throughout the body and only contributes to the emotions by sending oxygenated blood to our brain cells; so, if you want to gain someone's affection, you may have to ask Cupid to shoot them through the head rather than the heart. An arrow through the heart (or through the head, for that matter) would stop all bodily functions. The Medical Dictionary reports that the heart beats more than 2.5 billion times in an average lifetime. Isn't that "thumping"?

Inferior Vena Cava

The inferior vena cava is a large vein ascending through the abdomen. It collects blood from the hepatic veins, the lumbar veins, gonadal veins, renal veins, and phrenic veins. These vessels usually drain regions that are supplied by arteries with corresponding names. The inferior vena cava enters the heart through the right atrium.

Intermediate Antebrachial Vein

The intermediate antebrachial vein drains blood from dorsum of thumb and the elbow

Internal Iliac Artery

The abdominal aorta divides to form the "common iliac arteries" in the lower abdomen, and these vessels supply blood to the pelvic organs, gluteral region, and legs. Each common iliac artery descends a short distance and divides into an internal and an external branch. The internal iliac artery divides into many smaller branches to supply the various pelvic muscles and tissue structures, as well as the gluteal muscles (buttocks) and the external genitalia. Some of the important branches of this vessel include: (1) iliolumbar artery to the ilium (hipbone) and muscles of the back; (2) superior and inferior gluteal arteries to the muscles of the buttocks, pelvic muscles, and the skin of the buttocks; (3) internal pudendal artery to the alimentary canal, external genitalia, and hip joint; (4) the superior and inferior vesical arteries to the urinary bladder and, in males, the prostate gland; (5) middle rectal artery to the rectum; and (6) uterine artery to the uterus and vagina in females.

Iliac Vein

In the pelvic region, blood is carried away from organs of the reproductive, urinary, and digestive systems by vessels leading to the "internal iliac veins." These veins have many interconnections that form a network (called "plexuses") in the region of the rectum, urinary bladder, and prostate gland (in the male) or uterus and vagina (in the female). The internal iliac veins come from deep in the pelvic region and rise to the lower portion of the abdomen, where they join with the right and left "external iliac veins" and form the "common iliac veins." These, in turn, merge to produce the "inferior vena cava" at the level of the fifth lumbar vertebra.