The uterine blood circulation is specifically crucial for the menstrual cycle and pregnancy. A uterine artery emerges out of each internal iliac artery and travels via the broad ligament towards the uterus. It produces numerous divisions that perforate in the myometrium and create arcuate arteries.
Insertion, Relations and Pathway
Each arcuate artery travels within a circle close to the uterus and also anastomoses along with the arcuate artery on the other side. Throughout its course, it produces smaller arteries which perforate the rest of the way through the myometrium, in the endometrium, and also create the spiral arteries. The spiral arteries loop within the endometrial glands to the surface of the mucosa. They rhythmically contract and expand, helping make the mucosa alternately shrink and flush with blood.
The normal arcuate vessels are sometimes found inside the periphery of the uterus and should not be misunderstood for pathology. The radial arteries emerge as multiple divisions through the arcuate arteries and also go centrally in order to circulate the rich capillary network within the deeper layers of the myometrium along with the endometrium. Before going into the endometrium, the radial arteries produce the straight along with spiral arteries of the endometrium. These vessels are usually demonstrated among 1 and 3 weeks after the beginning of the last menses. Before the beginning of menses and while menses these vessels are less apparent. The vasodilating actions of estrogens on the uterus while midcycle and the vasoconstricting hormonal effects while the late luteal phase prior to menses describe the normal dynamic changes of these vessels.
After connecting with the wall of the uterus, the uterine artery move upwards in order to move tortuously with the lateral uterine sidewalls to connect with the upper portion of the uterus around the entrance of fallopian tubes. It continues to travel with the lower border of the fallopian tube where it terminates by anastomosing along with the ovarian artery, a direct division of the abdominal aorta. In this portion of its course, the uterine artery produces divisions, which move transversely and enter the myometrium. These are referred to as the arcuate arteries. They connect with the basal layers of endometrium where they are called as the basal arteries. From the basal arteries, spiral and straight arterioles of the endometrium are acquired.
The arcuate artery towards the cervix is also called the circular artery of the cervix. The uterine artery gives off a small descending branch which circulates the cervix along with the vagina. The uterine artery also circulates branches towards the fallopian tube and ureter as it goes across it. Cervicovaginal branches anastomose along with vaginal arteries in order to create the azygos arteries of the vagina.
Blood supply towards anterior and posterior walls is given by the arcuate arteries, which go circumferentially over the uterus. Via the arcuate vessels, branches called the radial arteries develop at right angles.
Calcification After Menopause
Calcifications may be found inside the arcuate arteries within postmenopausal women and look like peripheral linear echoes with shadowing. This is a normal aging process which may be increased within diabetic patients. Echogenic foci in the inner layer of the myometrium, which are normally nonshadowing, are thought to represent dystrophic calcification associated to previous instrumentation. Though they are of no clinical importance, they should be differentiated from calcified leiomyomas. Uterine perfusion (the vascular blood flow inside the myometrium) can be examined by Doppler sonography of the uterine arteries. The Doppler waveform usually shows a high-velocity, high-resistance arrangement.