The uterine horn is an integral part of the female reproductive system. Sometimes referred to as the uterotubal junction, the uterine horn is the part of the uterus that comes to a point and connects to its adjacent Fallopian tube, also known as the uterine tube; each end of the uterus has a uterine horn. This structure serves as an egg's pathway from a Fallopian tube to the uterus.
The uterine horn is just one part of the reproductive process. Typically about once a month, an egg will pass from either ovary through the nearest Fallopian tube. The horn is the point where the egg travels from the Fallopian tube, into the uterus. Once inside the uterus, the egg implants itself into the endometrial lining, or the endometrium, and awaits fertilization.
The female reproductive system contains muscles that are responsible for the essential uterine contractions that occur during menstruation, childbirth and orgasm. This muscle contraction is necessary for the egg's monthly journey from the ovaries to the uterus. Some theorize this structure has its own muscular sphincter, which would allow or deny passage of materials, but this theory has not been confirmed.
The round ligament originates at the horns of the uterus. The round ligament is critical to the female reproductive system. One reason is because it connects the uterus to the mons pubis, which is the mound of flesh protecting the pubic bone. It also is responsible for holding the uterus at an inclined angle above the bladder. Only in this position does the uterus have the capacity to expand and develop a fetus.
Sometimes, complications or malformations occur within the reproductive system and one or both of the Fallopian tubes do not connect with the uterine horns. Infection can also cause blockage and complicate the egg's path through the horn, making it difficult or impossible to conceive. In fact, some contraceptive devices purposefully block the horns of the uterus. If the egg cannot pass into the uterus, the body will absorb it.
Other reproductive and general health problems can result from malformed and/or dysfunctional uterine horns. Occasionally, if the uterine tubes are not adequately connected to the uterus, menstrual blood pools in the horns. If this happens, a simple one-day surgery should be enough to correct the problem.
Most mammals' reproductive systems are dependent on the uterus and therefore have uterine horns. The specific species' reproductive system dictates the size and quantity of functioning horns. Mammals that give birth to many babies at once, as in a litter, have larger uterine horns than mammals such as humans, who typically give birth to one offspring at a time.