Of the Birth canal summarizes all female reproductive organs that the baby has to pass through during its birth. During the contractions it leaves the uterus through the open cervix and is pressed out of the mother's body through the vagina. All of these organs belong to the human birth canal.
In humans, an unborn baby lies deep in the mother's pelvis, where it can develop well protected for 9 months. In contrast to fish or frogs, for example, humans can only give birth to one child per birth, as this child is much more likely to survive the birth and the first critical months of life than a newly hatched fish, for example.
The size of the human birth canal is therefore evolutionary, because the human baby is embedded in the body - it has to make this way when it is born in order to leave the mother's body. In addition to the vagina and the cervix in the broader sense, the birth canal also includes the mother's pelvis, as this can become one of the greatest hurdles for the unborn baby.
The birth canal thus serves the unborn child as protection against harmful and life-threatening environmental influences of all kinds during its development, since the mother can protect her child well as long as it is in her own body.
In a narrower sense, the birth canal in humans consists of the cervix and vagina. The cervix represents the entrance and exit of the uterus. During pregnancy it is tightly closed and additionally protected by a protective mucus plug.
As a result, no liquid can escape and germs can hardly penetrate up into the uterus, as they have to pass the cervix to do this. It opens in the course of the birth and thus opens the way for the baby to the further birth canal. If this does not happen, natural birth cannot take place. The vagina lies between the uterus and the outside world and also has a protective effect on the unborn child. Many pathogens die in the vagina because it has a slightly acidic environment and neither bacteria nor viruses can survive in it.
In a broader sense, the pelvis itself also belongs to the birth canal. The child initially lies in the mother's pelvis before it is pressed into the birth canal. Female pelvic bones are wider than males because a child's head and body must fit through them. If the child cannot pass through this part of the birth canal, natural birth is impossible.
The birth canal is especially important for the 9-month pregnancy, in which its components offer the unborn baby valuable protection. Humans only have one child per birth because they are able to offer a single offspring far better protection than other species.
While a human baby is developing, it is safe and well protected "behind" the protective mechanisms of the birth canal. The acidic environment of the vaginal lining prevents germs from reaching him before his immune system is sufficiently developed to deal with them. The cervix acts as an additional protection against diseases.
Since the unborn child is also in the mother's body, she protects herself from enemies at the same time and also protects her child as long as it has not yet made its way through the birth canal - at least that is the evolutionary idea behind this reproductive strategy. When the child is finally viable after nine months of pregnancy, every part of the birth canal enables him to give birth.
The pelvis is wide enough to let the head and body through. The cervix opens and gives way to the outside. The vagina serves as the final channel through which the child is forced through labor.
One of the most common complications affecting the birth canal is the pelvic bone. It is invariably formed in the adult woman, so that the child either fits through its shape - or in the worst case not. Before the possibility of receiving support from modern medicine, birth canals that did not fit the child's body resulted in broken bones or, in the worst case, deaths in both mother and child during childbirth.
The child could not leave the maternal body and serious birth injuries occurred. One of the hormonal problems affecting the birth canal is the cervix, which does not open despite labor. It should be open at least about 10 cm for a smooth birth - if it does not open at all or if it stagnates despite labor, the child cannot leave the uterus. An emergency caesarean section is necessary, just like with the unsuitable pelvis.
Furthermore, in the birth canal, the child may wind its own umbilical cord around its neck and either suffocate in the birth canal or suffer such severe damage from the lack of oxygen that it dies minutes or hours after birth. Depending on the position of the child, it cannot be born naturally through the birth canal - especially the breech position with the feet forward is problematic for a natural birth.