From the abdominal aorta are arteries that supply the lumbar region of the body known as the Lumbar artery. From the abdominal aorta, towards the splitting is the left Common iliac artery which then branches into the left external iliac artery, and the left internal iliac artery. The internal iliac artery splits to give the Superior Gluteal artery which supplies the Gluteus maximus muscle the gluteus medius and the gluteus minimus, Inferior to the Gluteal artery is the inferior gluteal artery which supplies the Gluteus maximus, the Quadratus femoris, Piriformis muscle, ischiococcygeus, and iliococcygeus.
In my last post, I discussed arterial flow and the arteries of the thorax and the abdomen, today I will be exploring the venous system of the thorax, the abdomen, and the lower limb.
Starting with the hepatic portal system. The Colon is supplied by the Superior mesenteric artery, so blood will be taken out of the area by the Superior mesenteric veins which receive blood from the right colic vein, the middle colic vein, the ileocolic vein, the intestinal vein, the gastro-omental veins, and the pancreatic duodenal vein. The inferior mesenteric vein also receives blood from the left side of the colon, through veins that include the left colic vein, the sigmoid vein, and the superior rectal vein. The splenic vein, the pancreatic veins, and the Gastro-epiploic vein return blood to the hepatic portal vein which is filled by the Superior mesenteric vein, the Inferior mesenteric vein, the gastric veins, and the cystic veins. The hepatic portal vein takes blood to the liver lobule through hepatic venules, where the blood is dropped to the sinusoidal capillaries where hepatocytes work to detoxify the blood and the blood goes to the inter lobule veins, then the hepatic veins which then sends the blood to the Inferior vena cava. From the Diaphragm, the Inferior phrenic veins, the Suprarenal veins, the renal veins, and the Gonadal veins all send blood to the Inferior vena cava. The right ascending lumbar vein is given off by the Inferior vena cava which then goes upwards to the diaphragm where they drain to the right posterior intercostal vein. The blood goes to the Azygos vein which then moves to the thorax and receives blood from the right posterior intercostal veins. The common iliac vein also gives blood to the left ascending lumbar vein which sends blood to the left posterior intercostal veins. When going to the thoracic region, it becomes the hemiazygos vein which will pick blood from the left posterior intercostal vein. The hemiazygos vein then empties the blood into the Azygos vein. The hemiazygos still continues to the accessory hemiazygos vein which also receives blood from the bronchial vein and the left posterior intercostal veins. The Accessory hemiazygos vein also goes to the Azygos vein, then into the Superior Vena Cava. The Superior Vena cava sends blood to the right Atrium., ,
Let me continue with the lower limbs of the body, basically, the plantar of the foot called the plantar digital veins then drain blood to the Plantar metatarsal veins which then send the blood to the plantar venous arch which branch to two structural veins which the Medial plantar veins and the lateral plantar vein. Both the medial plantar and the lateral plantar veins empty into a saphenous vein known as the small saphenous veins and the posterior tibial vein. The small saphenous vein drains the dorsal part of the foot and the plantar part of the foot. Let me quickly illustrate the veins in the Dorsum of the foot. From the dorsum of the foot are the dorsal digital veins which drain to the dorsal metatarsal veins, then to the dorsal venous arch, which then goes to the fibular vein, the dorsalis pedis vein, the small saphenous vein. This is how the small saphenous vein gets blood from both the dorsal and the plantar of the foot. From the dorsalis pedis vein blood is sent to two other arteries which are the anterior tibial vein, and the Great Saphenous vein. You see, the fibular vein sends blood to the Anterior veinThe small saphenous vein, the anterior tibial vein and the posterior tibial vein then send blood to the Popliteal vein. The popliteal vein and the great saphenous vein return blood to the femoral vein. Also, the Deep femoral vein sends blood to the femoral vein which sends the blood through the inguinal ligament to the External iliac vein. The internal iliac has some veins draining into it. Similar to what I wrote in my artery post, just that this time around it is going to be veins and not arteries.,
The veins are the Superior gluteal vein, Obturator vein which drains blood from the adductor region of the hip, Inferior Gluteal vein, the lateral sacral vein, the Internal Pudendal vein, the vesicle veins from the bladder, the Uterine vein and the vaginal veins for females, and the middle hemorrhoidal veins. The internal iliac and the external iliac vein come together to become the Inferior vena Cava which is below the diaphragm and then sends the blood to the right atrium. Above the diaphragm is the Superior Vena Cava which also sends blood to the Right Atrium. I explained the Superior Vena Cava Flow above.
After explaining the flow of blood back to the heart from the abdomen, the thorax, and the lower limb, certain pathophysiology can cause a problem with this flow to the heart. One of these conditions is the Budd-Chiari Syndrome which is an occlusion of blood in the hepatic system, which is usually caused by thrombosis in the hepatic veins leading to hepatomegaly (enlarged liver), and Ascites which is the presence of excess fluid in the abdomen.
Image Credit
Image 1 || Wikimedia Commons || Thoracic Abdominal Veins
Image 2 || Wikimedia Commons || Circulatory System
