nary, and digestive systems. This vein is formed by tributar-
ies corresponding to the branches of the internal iliac artery,
such as the
gluteal, pudendal, vesical, rectal, uterine,
Typically, these veins have many connections
and form complex networks (plexuses) in the regions of the
rectum, urinary bladder, and prostate gland (in the male) or
uterus and vagina (in the female).
The internal iliac veins originate deep within the pel-
vis and ascend to the pelvic brim. There they unite with the
right and left external iliac veins to form the
These vessels, in turn, merge to produce the
at the level of the F fth lumbar vertebra.
shows the major vessels of the venous system.
Clinical Application 15.7 looks at molecular explanations
of certain cardiovascular disorders. Clinical Application 15.8
discusses coronary artery disease.
begins in the lat-
eral portion of the foot and passes upward behind the lateral
malleolus. It ascends along the back of the calf, enters the
popliteal fossa, and joins the popliteal vein.
great saphenous vein,
the longest vein in the body,
originates on the medial side of the foot. It ascends in front of
the medial malleolus and extends upward along the medial
side of the leg and thigh. In the thigh just below the ingui-
nal ligament, it deeply penetrates and joins the femoral vein.
Near its termination, the great saphenous vein receives trib-
utaries from a number of vessels that drain the upper thigh,
groin, and lower abdominal wall.
In addition to communicating freely with each other,
the saphenous veins communicate extensively with the deep
veins of the leg and thigh. Blood can thus return to the heart
from the lower extremities by several routes.
In the pelvic region, vessels leading to the
carry blood away from organs of the reproductive, uri-
Head and upper
Lower limb capillaries
In this schematic drawing of the cardiovascular system, note how the hepatic portal vein drains one set of capillaries and leads to
another set. A similar relationship exists in the kidneys.