This is a view of the same uterus, from below. Here the urethral connection of the bladder can be seen clearly (the bladder is again displaced to the left), and
the body and horns of the uterus are more clearly differentiated from the broad ligament.
In this image, the bladder, fat and broad ligament have been stripped away, clearly revealing the uterine body and horns.
Here the cervix is clearly exposed, and can be seen as the raised section between
the forefinger and thumb of the hand.
In this image, the insemination pipette is seen being introduced through the cervix from the vagina, although the vagina itself has been removed. Note the index
finger is introduced slightly (up to almost the first knuckle), and is being used to guide the pipette into and through the cervix, as it would when carrying out an insemination.
On the left can be seen the different textures of the uterine/cervical/vaginal tissue. The darker section at the top is the endometrium, the light section in the middle of the image is the cervix,
and the lower section is the vagina.
The ovary (seen on the right) is roughly kidney-shaped, with the depression in the center of the lower side being the ovulation fossa, where the ova evacuated from the follicle (which "implodes"
rather than "explodes" upon ovulation), exits on its way to the uterus after ovulation. The follicle shown here outlined in red is approximately 2 cm, the size being measured from the outer
surface to the innermost extent (in this image therefore, from left to right). As a result, ultrasound is the only truly accurate method for establishing follicular size. Determination of size by
rectal palpation relies on the assumption that the follicle is spherical in shape, and although this is often the case, it is not always so. Even if the follicle is spherical, it is difficult to
determine the exact edge when using palpation. On the other hand, rectal palpation is of value in many cases to determine how close to ovulation the mare is, as the consistency of the
follicle typically softens dramatically close to ovulation, and this can be established using palpation with greater touch sensation. Ultrasound may detect either a "tear-shaping"; or a thickening of the outer membrane of the
follicle, both signs of impending ovulation, but these signs are not always present.
