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Variants and anomalies in the development of urogenital organs
Last reviewed: 23.04.2024
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Among violations of kidney development, there are anomalies due to the number. There is an additional kidney, which is formed from any side and lies below the normal kidney. A duplicate kidney (dup duplex), which occurs when one side of the primary kidney is divided into two equal parts, is rarely the absence of one kidney (agenesia renis). Kidney anomalies can be associated with their unusual position. The kidney can be located in the area of its embryonic bookmark - the distopia of the kidney (distopia renis) or in the pelvic cavity. Possible kidney anomalies in form. When the lower or upper ends of the kidneys are fused, a horseshoe kidney (ren arcuata) is formed. In the case of fusion of both lower ends of the right and left kidneys and both upper ends, a ring-shaped kidney (ren anularis) is formed.
If the development of the tubules and capsules of the glomeruli, which remain in the kidney in the form of isolated vesicles, develops a congenital cystic kidney.
Anomalies of the ureter are observed in the form of its duplication from two or one side. There is a split ureter rissus in its cranial or, rarely, caudal part. Sometimes constrictions or enlargements, as well as protrusions of the ureter's wall - the ureter's diverticulum, are formed.
With the development of the bladder may appear protrusion of its walls. Rarely there is underdevelopment of the wall (its cleavage), which is combined with non-growth of the pubic bones, - ectopia of the bladder (ectopia vesicae urinariae).
Anomalies of internal genital organs
Anomalies and variants of development of internal male and female sexual organs arise as a result of complex transformations of them in embryogenesis.
Of the anomalies of the sex glands, it should be noted underdevelopment of one testicle or its absence (monarchism), with a delay in lowering the testicles in a small pelvis or in the inguinal canal, there is a bilateral cryptorchidism. The vaginal process of the peritoneum can be uninflammated, then it communicates with the peritoneal cavity and a loop of the small intestine can protrude into the formed pocket. Sometimes the testicle lingers in the process of lowering, which leads to an unusual location (ectopia testis). In this case, the testicle may be in the abdominal cavity, either under the skin of the perineum, or under the skin in the region of the outer ring of the femoral canal.
In the process of development of the ovaries, there are also cases of their abnormal displacement (ectopia ovanorum). One or both ovaries are either placed at the deep inguinal ring, or pass through the inguinal canal and lie under the skin of the large labia. In 4% of cases, there is an additional ovary (ovarium accessorium). Occasionally, congenital maldevelopment of one and sometimes both ovaries takes place. Very rarely there is a lack of fallopian tubes, as well as the closure of their abdominal or uterine opening.
When the distal ends of the right and left paramezonephalic ducts are insufficiently coalesced, the bicornic uterus (uterus bicbrnus) develops, and with complete non-affection - the double uterus and the double vagina (a rare anomaly). In the case of delayed development of the paramezonephalic duct on one side, an asymmetric, or unicorn, uterus arises. Quite often the queen stops in its development. Such a womb is called infant (infantile).
[Anomalies of external genital organs
An anomaly of development of the male external genitalia is hypospadia (hypospadia) - incomplete closure of the urethra from below. The male urethra remains below as a gap of a greater or lesser length. If the male urethra is split from above, then its upper cleavage occurs - epispadia (epispadia). This anomaly can be combined with non-dissection of the anterior abdominal wall and anterior to the bladder (ectopia of the bladder). Sometimes the hole of the foreskin does not exceed the diameter of the male urethra and the head of the penis can not leave through such a hole. This condition is called fimosis.
To the rare anomalies of the development of the reproductive organs is the so-called hermaphroditism (two-cavity). Distinguish between true and false hermaphroditism. True hermaphroditism is very rare and is characterized by the presence of the same person in the testicles and ovaries in the male or female type of the structure of the genital organs. More common is the so-called false hermaphroditism. In these cases, the sex glands belong to the same sex, and the external genital organs, according to their characteristics, correspond to the other sex. Secondary sex signs at the same time resemble the signs of the opposite sex or are, as it were, intermediate. Distinguish between male false hermaphroditism, in which the sex gland differentiates as an egg and remains in the abdominal cavity. At the same time, the development of the genital rollers is delayed. They do not coalesce with each other, and the sexual tubercle develops insignificantly. These formations mimic the genital cleft and vagina, and the sexual lump is the clitoris. With female false hermaphroditism, the sex glands differentiate and develop as ovaries. They descend into the thickness of the genital rollers, which are so close to each other that they resemble a scrotum. The end part of the genitourinary sinus remains very narrow and the vagina opens into the genitourinary sinus, so that the opening of the vagina becomes less noticeable. Sexual tubercle considerably expands and imitates the penis. Secondary sexual characteristics take on a character characteristic of a man.