by Dr. David Fleischacker
As with men, the organic and psychic procreative life of women possesses an intelligibility that begins with the finality to conceive life. And as in men, the lower levels are intrinsically oriented toward higher levels of intelligibility. Another, way of saying this is that the lower levels of organic life possess intrinsic orientations toward higher levels of intellectual, rational, volitional life, and an obediential potency to a life of sanctified grace in faith, hope, and love.
Hence, as with the general way of proceeding established earlier, starting with the lowest levels of the procreative order to the highest, we will begin examining the women’s body in its organic structure with one exception, the neurological schemes. I will deal with the female neuro-schemes in a later blog, because the complexity requires separate treatment.
The female procreative order
The physiology of the women has a number of key elements that relate it to the conjugal union with a man, to the creation and formation of a new human being, and to nurturing the existence of the new life once born. For example,
- The ovaries provide a place for the developmental growth and maturation of oocytes.
- The uterus provides for the early formation of a child in the womb and the mother’s mammary glands for the early post-natal life of the child.
- The woman's body is bio-physically and bio-chemically structured for receiving the spermatozoa of the man and then facilitates the movement of the spermatozoa toward the oocyte.
These features point to the key elements of the female procreative schemes. Explanatorily, much more is involved. As has been recognized in earlier blogs, procreativity is an intelligibility that really belongs to the entire unity of a man and a woman. Hence, it is something that is an intelligibility that involves the integration of many of the recurrent schemes of correlation and recurrent schemes of development in the body. It is closely linked to the neural system, the endocrine system, the circulatory and respiratory systems, the muscular system, the skeletal system, and it is protected by the immune system. It is not merely a part of the body, but rather it is an ordered intelligibility of the many parts of the human body.
Prior to the woman's own birth, her body came to form all of the oocytes she will ever possess. However, it will take until adolescence before her body forms to a degree to support the formation and the nurturing of a new life. Once she reaches procreative maturity, her body has undergone a series of changes that have capacitated her to receive a man and his spermatozoa and to mature her own oocytes for 1) release, 2) fertilization, 3) implantation, 4) growth in the womb, and then 5) growth as an infant. Many of the biochemical schemes involved in all of these stages are simply unknown. However, many have been learned in the last few decades because of the high profitability and the demand for the “reproductive” and contraceptive industries.
As was mentioned in earlier blogs, the oocyte is structured to receive one and only one spermatozoa. Here is a small refresher. The zona pelucida that surrounds the oocyte is species specific (meaning that spermatozoa from another species could not penetrate it). Furthermore, once a spermatozoa has worked its way through the zona and becomes incorporated into the oocyte, the egg shifts its structure to hinder the entrance of other spermatozoa. Hence, the oocyte has a functional and schematic relationship to the spermatozoa. This scheme forms a new type of being, one that has an intrinsic developmental finality and this finality is oriented toward the mature human adult. On their own, the spermatozoa and the oocyte do not possess this developmental capacity.
Now let us turn to the woman's body. Oocytes are found within the ovaries. Since the woman's body is the location where the first 9 months of life are formed, her body is on a kind of recharge cycle that is roughly one month in length (interestingly, I did read one study that argued that if a woman is in a largely natural light environment, her cycle will line up with the cycles of the moon). This recharge cycle is needed because of how her body has to prepare itself for the possibility of nurturing a new life which requires a tremendous amount of energy to accomplish. Without the recharge cycle, the woman’s body would be in a constant state of fertility, which would require for example a constant release of a sufficiently matured oocytes, a constant state in which the uterus is prepared for implantation, a constant state of readiness that would burn tremendous amounts of calories and other nutrients far beyond her normal human intake. From a scientific viewpoint, here are some of the steps involved in the cycle.
Follicular Phase → Luteal Phase
Relationship to creation of new life
Let us begin our explorations of the monthly cycle of a woman with the follicular phase. This phase derives its name from the follicles which reside within the woman's ovaries. Each follicle contains an oocyte which is surrounded by a kind of protective sheath of cells (granulosa cells). At the beginning of this phase, hormones trigger some of the follicles in the woman's ovaries to begin to mature, which means that the oocyte grows in size, adding components that would be needed for fertilization and by an embryonic human being. When the maturation of the follicle begins to take place, the granulosa cells divide and increase in number, forming multiple layers around the oocyte, and between these layers an atrial pouch forms that fills with fluids, rich in hormones. This process leaves just one layer of granulosa cells around the oocyte. At the same time, these cells secrete a layer of thick gel around the oocyte called the zona pellucida. 14 days after the follicular phase begins, the most mature follicle will burst open, releasing the oocyte with its zona pellucida and the one layer of granulosa cells. This release marks the end of the follicular phase and the beginning of the luteal phase. The remaining part of the follicle then forms into a corpus luteum. Blood vessels have permeated this corpus, and the cells begin to produce progesterone and some estrogen, which then travel into these blood vessels and subsequently into the body, triggering various responses. One of the important responses in the woman’s body is the modification of the uterus, creating a special lining suitable for implantation and the growth of a young child. If no fertilization results, then the entire scheme returns to the follicular phase to begin the cycle anew. The entire meaning of these schemes is oriented toward the creation of new life.
Relationship to man
One can also focus on a variety of other changes that take place in the woman's body. Some of these relate the woman to a man. The woman begins to secrete a mucous that is designed to facilitate the conjugal act. The woman's olfactory senses come to respond to male pheromones in a new way. During the conjugal act, the triggering of similar schemes as found in the male body results in the expansion of blood vessels in a variety of places in her body. It also results in a contraction of muscles in her body that work to move the spermatozoa more completely into her body, and into the regions that have been prepared to direct and facilitate the movement of the spermatozoa toward the oocyte.
Luteal Phase → Pregnancy
If conception of the zygotic person takes place and implantation occurs, the woman's body then begins another set of changes that prepare for her role in forming the young boy or girl in her womb, and subsequently in nursing and caring for him or her in the first years of life. The implantation itself triggers various changes, including the release of a hormone that keeps the uteral lining from disintegrating and shedding. Even her brain will undergo significant changes to facilitate both bonding as well as increased abilities to attend to the needs of the child within the environment (thus, this facilitates increases in some of the cognitive abilities of the woman as well—more on that in a later blog).
Pregnancy → Birth
Once the child is born, the preparation taking place in the woman's mammary glands during pregnancy then gives way to small quantities of breast milk called colostrum, specifically designed for the needs of the newborn. Then, the nutrients shift to “milk” for the duration of nursing. Interestingly, during nursing, the nerves triggered release two hormones from the pituitary gland in the brain: prolactin and oxytocin. Prolactin then triggers the mammary glands to pull proteins and sugars from the blood stream to produce the milk. Oxytocin results in triggering cells in the breast to contract and push the milk out. Oxytocin also causes cells in the uterus to contract, thus shrinking it. Nursing also inhibits a hormone needed for the maturation and release of new oocytes, hence the reason that many, though not all, women who are nursing will not become pregnant until nursing ceases.
Far more can be said about many of these interlocking procreative schemes, however, the few mentioned here should be sufficient to give the reader an appreciation of the close integration of many events that take place in the women’s body and which form the procreative organic schemes.
This language follows the neuro-scientist Shewmon who has argued for a variety of “wholistic” properties that belong to the body as a whole, and really require the integration of a variety of different parts of the body. Hence, for example, healing of the body requires the operative integration of many systems, and is really not a property of just one part of the body. Likewise, the procreative life of the body is not merely the result of the uterus or the vagina or the ovaries. It really is an feature of an integration of many schemes.
 As a note, this key fact is one of the grounds for claiming that the human person begins at this point, though because of the intrinsic independence of the human capacity for self-transcendence from the empirical residue, this is not as easy as one might suppose. I presented this in an earlier set of blogs (“When does the human person begin to exist?”)
 As a note, recent studies in the last few years indicate that women will be more attracted to men with a greater complementarity in their immune systems. This complementarity however is not found if the woman is taking the contraceptive pill. For one summary of this, see this BBC article: http://news.bbc.co.uk/2/hi/health/7558499.stm.
 The argument that the zygote is a human person was made in another set of blogs entitled “When does the human person begin to exist?” In this blog, I started with St. Thomas' definition of a person.
 You can find a summary of these points at http://www.babies.sutterhealth.org/breastfeeding/bf_production.html. Another interesting study linked oxytocin to bonding. Here is a summary of it.http://www.sciencedaily.com/releases/2007/10/071015110059.htm.