Arteries and veins of the female pelvis.
Hello, everyone! This is Megan from Kenhub, and welcome to another anatomy tutorial. In today's tutorial, we will be looking at the blood vessels of the female pelvis. Before we begin, I'm just gonna give you a quick overview of the things we're going to cover today. So, here, we can see a lateral view of the pelvis. We can see the blood vessels found in the pelvis and the structures they supply such as the rectum, the uterus and the urinary bladder. So, as I said, we're going to be looking at the blood vessels found in the female pelvis.
First, we're going to look at the arteries that supply the structures found in the pelvis. These structures include the pelvic viscera, the pelvic walls and floor, and some structures in the perineum. Then, we'll have a look at the veins that provide the venous drainage of the pelvis. The blood vessels of the female pelvis are pretty similar to the male pelvis with the exception to those that supply the genitalia. Let's begin with the arteries that supply oxygen-rich blood to the pelvis. It's important to note that the arteries supplying the pelvis are mainly derived from the left and right common iliac arteries. So, if we look at this flow chart, we can see that the abdominal aorta gives rise to the left and right common iliac arteries. These arteries then give rise to the internal and external iliac arteries.
The left and right common iliac arteries are large arteries that arise from the bifurcation of the abdominal aorta at the level of the L4 vertebra. Here, we can see the abdominal aorta and we can see it dividing into the right and left common iliac arteries. We can see them highlighted in green in these images. The common iliac arteries then split into the internal and external iliac arteries. All of the branches of the common iliac artery are paired arteries. That means, you have one on either side. This supplied the same structures on both sides of the pelvis. So, let's look at the external iliac artery.
The external iliac arteries are branches of the common iliac artery on either side. They arise from the bifurcation of the common iliac artery just anterior to the sacroiliac joint here. The external iliac artery gives off several branches: the inferior epigastric artery, the deep circumflex artery and then it gives off its terminal branch, the femoral artery. These arteries will not be covered in this tutorial as the external iliac arteries are actually the main arteries that supply the lower limb rather than the pelvis.
The left and right internal iliac arteries also arise from the bifurcation of the common iliac arteries. This artery is the main artery of the pelvis. It gives off several branches which supply the pelvic region. Even though it's smaller than the external iliac artery, the branches of the internal iliac arteries supply the walls and viscera of the pelvis and the buttocks. They also supply the reproductive organs except the gonads which in this case would be the ovaries. The ovaries are supplied by the ovarian artery instead which arises directly from the abdominal aorta at L2.
In this image, we can see the left internal iliac artery in the sagittal plane and, in the next illustration, we can see the right internal iliac artery in the coronal plane highlighted in green. So, the branches of the internal iliac artery can be divided into two groups: the branches of the anterior division and the branches of the posterior division. Again, many branches of the internal iliac artery in females are the same as males excluding those that supply the reproductive structures. They are also all paired arteries meaning that they supply the same structure on both sides of the pelvis.
The branches of the anterior division of the internal iliac artery are the uterine artery, the obturator artery, the umbilical artery, the vaginal artery, the superior vesical artery, the middle rectal artery, the internal pudendal artery and the inferior gluteal artery. Then we have the posterior division of the internal iliac artery. Luckily, there are only three branches to remember for this division and those are the iliolumbar artery, the lateral sacral artery and the superior gluteal artery. As we can see, there are a lot of branches to remember especially when we're looking at the anterior division. So, the easiest way to remember which ones belong to which is to memorize the three that belong to the posterior division. And, from that, you can remember what branches are in the anterior division.
The first branch we're gonna look at today is a branch of the anterior division – the inferior gluteal artery. The reason we're gonna look at this artery first is because it doesn't actually supply structures within the pelvis. It is a large terminal branch of the anterior division that passes over the sacral plexus and lesser pelvis through the greater sciatic foramen. It supplies the gluteal region and its branches anastomose or connect to the superior gluteal artery, the obturator artery and the circumflex femoral artery. If we zoom in on this image, we can see the inferior gluteal artery leaving the greater sciatic foramen here. It passes under piriformis and goes to supply the gluteal region. So, now, that we've looked at the inferior gluteal artery, let's begin with the posterior division of the internal iliac artery.
As I said before, there are three branches to this division. They are the iliolumbar artery, the lateral sacral artery, and the superior gluteal artery. In this image, you can see the left iliolumbar artery. It's traveling upwards and is highlighted in green. It is the first branch of the posterior division and leaves the pelvic cavity through the pelvic inlet. It travels beneath the psoas major muscle and into the iliac fossa. It further divides into two branches: a lumbar branch and an iliac branch, hence, the name, iliolumbar artery. The second branch of the posterior division is the lateral sacral artery. As I said, it’s a branch of the internal iliac artery. It travels inferiorly and laterally lateral to the medial sacral artery. This artery gives off spinal branches and supplies the sacral canal, the piriformis muscle, and the erector spinae muscles. Here we can see this artery highlighted in green traveling downwards.
The third and final branch of the posterior division of the internal iliac artery is the superior gluteal artery. It is the largest branch of the posterior division. It leaves the pelvic cavity through the greater sciatic foramen. So, here, we can see the greater sciatic foramen and we can the superior gluteal artery in green passing through it to exit the pelvis. Once it's exited the pelvis, it gives off branches to the iliacus muscle, the piriformis muscle, the obturator internus muscle, and the gluteal muscles.
We have now covered all of the branches of the posterior division of the internal iliac artery. So, next, we're going to look at the branches of the anterior division. The first artery of the anterior division that we're going to look at is the uterine artery. As its name suggests, it supplies the uterus. We can see it highlighted in green here and, over here, we can see its branches supplying the uterus. This artery travels to the cervix through the parametrium of the broad ligament lateral to the uterus on either side. The uterine artery gives off vaginal, ovarian and tubal branches as well as a branch to the round ligament of the uterus. It also anastomoses with the ovarian artery that I mentioned before. In pregnancy, the uterine artery and its branches become substantially bigger to provide an increased blood supply to the uterus and developing fetus. In the male pelvis, the uterine artery corresponds to the artery of the vas deferens.
The next branch of the anterior division of the internal iliac artery is the obturator artery. We can see the left one here highlighted in green. It supplies the adductor muscles in the thigh. It travels anteriorly and inferiorly along the lateral wall of the pelvis and passes through the obturator foramen on either side of the pelvis. It gives off branches inside the pelvis and a posterior and anterior branch once it's gone through the obturator foramen. The umbilical artery, like the other branches of the internal iliac artery, is a paired artery. This means you have a left and right umbilical artery. It gives rise to the superior vesical artery. In adults, the umbilical artery is obliterated between the bladder and the umbilicus. Here, a fibrous remnant remains forming the medial umbilical ligament.
The superior vesical artery as I mentioned in the previous slide represents the terminal branches of the umbilical artery on either side of the pelvis. So, there is a left superior vesical artery and a right superior vesical artery. In this image, we can see the superior vesical artery supplying the urinary bladder here. The superior vesical artery supply the upper and middle segments of the urinary bladder and provides some branches to the distal part of the ureter as well. The next branch of the anterior division of the internal iliac artery is the vaginal artery. Again, there's a left and right vaginal artery. We can see it highlighted in green on the image here. This artery supplies the vagina and the base of the bladder.
The next artery of the anterior division is the middle rectal artery. It is also a paired artery. It travels to the rectum on the pelvic floor and supplies the rectal muscles. In the female pelvis, it also supplies branches to the lower part of the vagina. It anastomoses or connects with a number of arteries. These are the inferior vesical artery, the superior rectal artery, the inferior rectal artery and with branches of the inferior mesenteric artery and the internal pudendal artery. The illustration shows a left and right middle rectal arteries. Here, we can see it in green supplying the rectum.
The internal pudendal arteries, together with the inferior gluteal arteries, are the terminal branches of the anterior division of the internal iliac artery. The right and left pudendal arteries supply the external genitalia. This artery is bigger in males than in females. It leaves the pelvic cavity through the greater sciatic foramen and enters the perineum through the lesser sciatic foramen. It runs on the lateral wall of the ischiorectal fossa and gives off branches to the labia, clitoris and the perineum. It also gives rise to the inferior rectal artery. For more information on the branches of the internal pudendal artery in the male pelvis, please check out our video tutorial on blood vessels of the male pelvis on our website.
Unlike most of the blood vessels we're discussing in this tutorial, the superior rectal artery is not a branch of the internal iliac artery. This artery supplies the rectum including the mucosa up to the anal valves. It is also a branch of the inferior mesenteric artery. The superior rectal artery runs behind the rectum descending into the lesser pelvis and dividing into a left and right branch before piercing the musculature of the bowels. Here we can see the superior rectal artery highlighted in green supplying the rectum.
As I've mentioned before, the inferior rectal artery is a branch of the internal pudendal artery. It travels through the ischiorectal fossa and supplies the lower half of the anal canal including both sphincters and the skin below the anal valves. In the illustration, you can see the right inferior rectal artery supplying the internal and external anal sphincters.
The median sacral artery is a small unpaired artery that arises from the posterior part of the abdominal aorta just superior to its bifurcation at the level of L4. As you can see in the illustration, the artery travels inferiorly in the midline, crosses the pelvic inlet and then travels along the anterior surface of the sacrum and the coccyx. Its branches supply the posterior surface of the rectum. It also anastomoses with the iliolumbar artery and the lateral sacral arteries. In the following image, we can see the median sacral artery. It's arising from the abdominal aorta here and travels down to supply the posterior surface of the rectum.
We have now covered the anterior and posterior divisions of the internal iliac artery. Let's have a look at the venous drainage of the female pelvis. The veins in the pelvis include the superior rectal vein, the middle rectal vein, the inferior rectal vein, the internal pudendal vein, the vesical veins, the inferior vesical vein, and the vaginal venous plexus. There is also the obturator vein, the uterine vein, the uterine venous plexus, the internal iliac vein, the external iliac vein, and the common iliac vein. For the most part, these veins follow the course of their artery counterpart. You will see in the following slides that these veins drain into the internal iliac vein and, subsequently, the common iliac vein with one exception which is the superior rectal vein.
The superior rectal vein follows the course of the superior rectal artery. It drains blood from the veins surrounding the rectum. It then travels superiorly, crosses the common iliac vessels and drains into the inferior mesenteric vein and, finally, the hepatic portal vein. The paired middle rectal veins arise from the hemorrhoidal plexus also known as the rectal venous plexus. These veins anastomose with the superior rectal vein and the inferior rectal veins. Unlike the superior rectal vein, the middle rectal veins drain into the internal iliac vein and, finally, into the caval system. In these illustrations, we can see the middle rectal vein highlighted in green here and here.
The inferior rectal veins are also paired veins. They drain the inferior part of the external rectal venous plexus. They drain into the internal pudendal vein. They also anastomose with the superior rectal vein and the middle rectal veins. These veins can become varicose resulting in external hemorrhoids or piles. We can see the inferior rectal vein highlighted in green here. The left and right internal pudendal veins receive tributaries from the labia, clitoris, the perineal veins and the inferior rectal veins. They follow the course of the internal pudendal arteries in the lateral wall of the ischioanal fossa, escaping the female pelvis through the infrapiriform foramen. It then drains into the internal iliac veins.
The vesical veins drain blood from the urinary bladder into the internal iliac veins. The veins form the vesical venous plexus. Here, we can see the vesical veins draining the urinary bladder. Now, let's look at the inferior vesical veins. The inferior vesical veins drain into the internal iliac veins. We can see the left vesical vein highlighted in green here. When we talk about the vesical veins, we are referring to the veins arising from the vesical venous plexus. This plexus wraps around the base of the bladder and anastomoses with the vaginal venous plexus in the female pelvis.
The vaginal venous plexus I just mentioned before refers to a network of small veins that drain via the vaginal veins into the internal iliac veins. The vaginal venous plexus anastomoses with the uterine, vesical and rectal venous plexuses. Here, we can see the vaginal venous plexus surrounding the vagina. Now, let's move on to the obturator vein. The obturator veins drain into the internal iliac veins. These veins form in the adductor region of the thigh and pass into the pelvis through the obturator foramen. They also have an anterior and posterior branch much like the obturator artery.
The network of veins that make up the uterine venous plexus is found between the two layers of the broad ligament of the uterus. The uterine venous plexus drains the blood from the uterus into the internal iliac veins via the uterine veins. The uterine venous plexus also anastomoses with the vaginal and ovarian venous plexuses. Here, we can see the uterine venous plexus surrounding the uterus. The left and right uterine veins are connecting veins that join the uterine venous plexus to the internal iliac veins. These veins are situated in the cardinal ligament which is located at the base of the broad ligament of the uterus. We can see it here highlighted in green.
The left and right internal iliac veins are the main veins of the pelvis. They're also known as the hypogastric veins. They receive tributaries from the perineum and the pelvic viscera and they drain into the common iliac veins. The internal iliac veins join the external iliac veins to form the common iliac veins on both the left and right side. In the next image, we can see the right internal iliac vein in a close-up here highlighted in green. The external iliac veins are also paired veins and they are formed by the femoral veins on either side. The external iliac veins follow the external iliac arteries. These veins join with the internal iliac veins to form the common iliac veins on both the left and right side. We can see the external iliac vein here following the external iliac artery.
The left and right common iliac veins drain into the inferior vena cava which is formed when the veins merge at the level of L5. All of the blood from the lower extremities and pelvis drains into the inferior vena cava which carries the blood to the heart. We can see the inferior vena cava here highlighted in green next to the abdominal aorta.
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