Arteries of the Hindlimb - Anatomy & Physiology
The abdominal aorta terminates by branching into the external iliac arteries and the internal iliac arteries. It is these arteries that supply the hindlimb and pelvis.
(Note: Although the information below is based around the anatomy of the canine hindlimb, it is essentially the anatomy of the arteries in similar domestic species. Any major differences will be discussed on their respective pages.)
The Internal Iliac Artery
These are paired arteries with a right and left branch and are terminal branches of the aorta. They provide a blood supply to the pelvic viscera, the walls of the pelvic cavity and the lumbar and gluteal muscle masses. The following describes the initial branches (in order) of when they branch off and arteries of particular relevance to the hindlimb will be indicated.
The median sacral a. arises from either the left or right internal iliac and supplies the sacrum and tail. The internal pudendal a. is the primary branch of the internal iliac and provides blood to the reproductive organs and urinary tract. The caudal gluteal a. supplies the superficial gluteal muscle and the proximal 'hamstring muscles'. The iliolumbar a. is the first branch of the caudal gluteal and supplies the psoas minor, iliopsoas, sartorius, tensor fascia lata and the middle gluteal muscles. The cranial gluteal a. arises from the caudal gluteal and passes over the greater ischiatic notch and supplies the gluteal muscles. The tail is supplied by the lateral caudal a. whilst the dorsal perineal a. supplies the perineum.
External Iliac Artery
The external iliac artery is the principal artery of the hindlimb. Once it branches from the aorta it runs along the ilial body. Prior to entering the femoral canal (formed by the sartorius cranially and the gracilis and pectineus caudally) it detaches the deep femoral a. and on leaving the abdomen the external iliac continues as the femoral a.. The femoral a. continues between the adductor muscles on the medial aspect of the thigh to reach the caudal side of the stifle. Here it continues as the popliteal a.. There are a number of arteries that branch off the external iliac, femoral and popliteal arteries with the prominent branches highlighted below.
From the external iliac a., the first branch is the deep femoral a. which arises in the abdomen near the femoral canal and gives rise to the short pudendoepigastric trunk before continuing as the medial circumflex femoral a.. The pudendoepigastric trunk then branches into the caudal epigastric a. which runs cranially on the deep aspect of the straight abdominal muscles. The second branch of the external iliac a. is the external pudendal a. which runs through the inguinal canal and branches off to supply numerous reproductive structures. The third branch is the medial circumflex femoral a. and this supplies the caudal half of the rectus abdominus and the muscles of the medial thigh.
The first branch of the femoral a.is the superficial circumflex iliac a. which supplies the sartorius, tensor fascia lata and rectus femoris. The lateral circumflex femoral a. which branches off the superficial circumflex iliac a. supplies the quadriceps, tensor fascia lata, the superficial and middle gluteals, and the hip joint capsule. The proximal caudal femoral a. is the second branch from the femoral a., branching at the mid-thigh region and supplying the pectineus, adductor muscles and gracilis. The third branch is the saphenous a. which arises proximal to the stifle and supplies the skin on the medial aspect of the stifle. The saphenous a. also has cranial and caudal branches. This artery and its vessels lie very superficially and the cranial branch gives rise to the dorsal common digital aa. and the caudal branch gives rise to the plantar common digital aa.; both of which supply the foot. The branches following the saphenous a. in order are the descending genincular a. supplying the medial surface of the stifle, the middle caudal femoral a. supplying the distal parts of the adductor and semimembranosus muscles and the distal caudal femoral a. which is the last branch of the femoral a. before it becomes the politeal a.. It supplies the biceps femoris, semimembranosus, semitendinosus, gastrocnemius and the digital flexors.
The popliteal a. supplies the stifle, gastrocnemius, popliteal muscle and terminates by branching into the cranial and caudal tibial aa.. The cranial tibial a. supplies the peroneus longus, long digital extensor and cranial tibial muscles whilst the caudal tibial a. is a small branch that lies in the interosseous space between the tibia and fibula. The dorsal pedal a. is a continuation of the cranial tibial a. and runs over the flexor surface of the tarsus and supplies the tarsus. The arcuate a. branch is the main blood supply to the foot. The dorsal metatarsal aa. supply the paw dorsally whilst the perforating branch (of the) metatarsal aa. forms an anastomoses with the caudal branch of the saphenous a. and contributes to the plantar metatarsal arteries that supply the digits.