The uterine arteries
Keywords: uterus, artery, middle, arteries, anatomyDuring transrectal palpation of the pregnant bovine uterus, it is common to feel for the presence of fremitus in a uterine artery. A video of a windsock, simulating fremitus can be seen here. It shows non-linear, turbulent flow of air through a windsock; the sock is unable to constrain the airflow in a linear, orderly fashion. During pregnancy in ruminants, blood flow to the uterus increases rapidly, exceeding the ability to contain the blood flow in a linear flow. The effect is the same in both cases.
Since antiquity, this artery has been referred to by clinicians as the middle uterine artery, implying that there are several major arteries within the mesometrium. Indeed, this is clearly the case as shown below (A, B & C...perhaps more). However, the image also shows that there is only major uterine artery (UA) from which the smaller arteries emanate. That artery should correctly be referred to as the uterine artery.
Image size: 1500 x 1000px
The question arises as to which of these arteries can develop fremitus during pregnancy. Clearly the major artery is capable of doing so. Therefore if there is any doubt as to which artery one is grasping during pregnancy diagnosis, it may be most correct to refer to "fremitus in the uterine artery" rather that "fremitus in the middle uterine artery". Finally, there is clearly potential for the development of an even number of large arteries in the mesometrium, in which case there can be no middle artery. Collectively therefore, the term "middle uterine artery" is probably incorrect in many instances of transrectal palpation. In the absence of clinical evidence to show otherwise, the term "uterine artery" should be used.
