Anatomy & Physiology

Anatomy & Physiology Study Guide common iliac arteries, which transport blood to the pelvis and lower limbs, descend posterior to the cecum and sigmoid colon along the inner surface of the ilium. At the lumbosacral joint, each common iliac divide to form an internal iliac artery and an external iliac artery. The internal iliac arteries enter the pelvic cavity to supply the urinary bladder, the internal and external walls of the pelvis, the external genitalia, the medial side of the thigh, and, in females, the uterus and vagina. The major tributaries of the internal iliac artery are the gluteal, internal pudendal, obturator, and lateral sacral arteries. The external iliac arteries supply blood to the lower limbs and are much larger in diameter than the internal iliac arteries. Arteries of the Thigh and Leg Each external iliac artery crosses the surface of an iliopsoas muscle and penetrates the abdominal wall midway between the anterior superior iliac spine and the pubic symphysis on that side. It emerges on the anterior, medial surface of the thigh as the femoral artery. Roughly 5 cm (2 in.) distal to the emergence of the femoral artery , the deep femoral artery branches off its lateral surface. The deep femoral artery, which gives rise to the femoral circumflex arteries, supplies blood to the ventral and lateral regions of the skin and deep muscles of the thigh. The femoral artery continues inferiorly and posterior to the femur. As it approaches the knee, it gives rise to the descending genicular artery, which supplies the area around the knee. At the popliteal fossa, posterior to the knee joint, the femoral artery becomes the popliteal artery , which then branches to form the posterior and anterior tibial arteries. The posterior tibial artery gives rise to the fibular artery, or peroneal (perone, fibula) artery, before continuing inferiorly along the posterior surface of the tibia. The anterior tibial artery travels between the tibia and fibula, coming out on the anterior surface of the tibia. As it moves downward toward the foot, the anterior tibial artery provides blood to the skin and muscles of the anterior portion of the leg. Arteries of the Foot When it reaches the ankle, the anterior tibial artery becomes the dorsalis pedis artery, which then branches repeatedly, supplying the ankle and dorsal portion of the foot. As it reaches the ankle, the posterior tibial artery divides to form the medial and lateral plantar arteries, which supply blood to the plantar surface of the foot. These arteries are connected to the dorsalis pedis artery through a pair of anastomoses. The arrangement produces a dorsal arch and a plantar arch; small arteries branching off these arches supply the distal portions of the foot and the toes. 20.12 Systemic Veins The Superior Vena Cava All the body’s systemic veins (except the cardiac veins) ultimately drain into either the superior vena cava or the inferior vena cava. The superior vena cava (SVC) receives blood from the tissues and organs of the head, neck, chest, shoulders, and upper limbs.

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