Ovaries

Today, I tackle a body part upon which I consider myself to be somewhat of an expert. Had my left ovary behaved years ago, I would not be typing this today–and I would still have both ovaries. Speaking with other women, it becomes obvious very quickly that we tend to know very little about our ovaries.  Hopefully, I will shed some light on this for you today!

Where are the ovaries?  It’s safe to say we know they’re in our pelvis, but where exactly?  A good estimate is to make a triangle with with your index fingers and thumbs and place that over your pelvis with the index fingers pointing downward.  In the upper corners is about where your ovaries are.  (They tend to be a bit lower and more centralized than most assume they are.)  The ovaries are held in place by a network of ligaments which also attach to the uterus and Fallopian tubes.  The ovaries are not connected directly to the Fallopian tubes.  Many diagrams shows the fimbriae (the leafy looking parts on the far left and right below) of the Fallopian tubes as been directly adjacent to the ovaries, which leads many to believe that the ovaries are directly attached to them.  They are not.  (Read more about the relationship between the ovaries and the Fallopian tubes in the section about Fallopian tubes.)

The ovaries are, ironically, shaped like eggs but are smaller than the chicken eggs that one typically purchases at the grocery.  The ovaries are about the size of a walnut, are slightly pearl colored, and have bumpy, soft surfaces.  The ovaries are responsible for producing a variety of sex hormones.  At birth, the ovaries of a healthy baby girl contain between one and two million eggs.  By the time puberty begins, most of these have wasted away leaving about 300,000 eggs–plenty for the reproductive lifespan.  Thus, a woman has a finite number of eggs, but men have a different mechanism that continually makes sperm.  This is why women have “childbearing” years, but men can father children throughout their adult lives.

The eggs have a complicated lifespan before they are even released for potential fertilization.  The term “egg” is generic and refers to a single cell’s journey through maturation.  Before maturation, the egg is referred to as an oocyte.  Once it finishes maturing (see diagram below), it becomes an ovum and three polar bodies.  The polar bodies are actually inside of the ovum and serve to “fuel” the egg once it is fertilized continuing cell division and replication before it implants in the uterine lining (where it forms a network of blood vessels that forms the placenta and umbilical cord).

Each month, the ovaries usually release one mature egg (not one from each).  The ovaries are covered in cells called follicles and within each follicle is a single egg.  Once an egg is matured, the process of ovulation can begin.  During this time, the follicle that houses the mature egg expands and eventually ruptures forcing the egg outward.  This rupturing is completely normal–it would be abnormal for ovarian follicles to never rupture, and in fact some women can actually feel a quick pain when the rupture occurs.  The diagram below is an illustration of the ovulation process, beginning in the upper-left hand corner and going clockwise.

Following a woman’s “childbearing” years, the ovaries continue to play an important role.  For years, many doctors prescribed a surgery called a hysterectomy to remove the ovaries (as well as the uterus and Fallopian tubes) once a woman was finished having children.  This was performed to prevent cancer from developing.  However, we now know that ovarian cancer can actually develop anyway after the ovaries have been removed.  This is because the ovaries share tissue with the internal cavity that remains following a hysterectomy.  Leaving the ovaries intact provides a number of hormonal benefits throughout menopause that are difficult to replace.  Thus, the benefits of leaving the ovaries intact often outweigh the drawbacks.  (This is something that should be discussed with a physician, because each individual has a different medical history that will affect any such decision.)

There is a lot more that could be said about ovaries, but let’s save that for another day.  Hopefully this gives you a better understanding of how the ovaries work!

The Uterus

Pound for pound, the uterus is the strongest muscle in the human body. The uterus weighs about 40 ounces (2.5 pounds; 1.1 kg) and is about the size of a pear when not pregnant. Yet, in the process of giving birth, the uterus can exert over 100 pounds of force (440 newtons). The uterus is responsible for protecting and nursing a growing fetus during a pregnancy, and also for pushing that fetus out when it’s time to give birth. Let’s further explore this great muscular feat of nature–the human uterus.

The word uterus comes from Latin meaning “womb” or “stomach.”  It is an organ particular to mammals.  The human uterus consists of two parts:  the main body, generally just called the uterus, and the narrow “neck” called the cervix (Latin for “neck”).  In humans, the uterus is labeled as simplex because it is generally a single (simple) compartment, but sometimes the uterus does not end up like this.  When a female fetus is developing in the womb, it starts out initially as an organ shaped like a V–as though the cervix has two horn-shaped compartments.  As the fetus develops, the horns will generally fused into one, “simplex” uterus.  About 6.7% of the time, though, this does not happen resulting in a malformed uterus.

The most common type of malformation is the bicornuate (or “two-horned”) uterus.   Other malformations include unicornuate (“one-horned”) uterus, double uterus (two whole, functioning uteruses), and absent uterus (where the uterus fails to develop at all).  Each of these malformations has its own set of issues, and a medical professional can help counsel a person with a malformed uterus.

The uterus consists of three main “layers,” much like the different layers of skin.  The innermost layer on the inside of the uterus is called the endometrium.  It is a temporary layer that builds up and jettisons away over the course of a menstrual cycle.  The middle layer is called the myometrium.  This is the main, muscular layer of the uterus and consists of smooth muscle mass.  The outermost layer is referred to as the perimetrium.  It is a thin membrane that secretes serous fluid.

In the reproductive cycle, the uterus receives the egg after it has been fertilized while traveling down the Fallopian tube (labeled here as the uterine tube).  Once the fertilized egg is in the uterus, it will usually implant in the endometrial lining of the uterus (that is normally shed when a woman has her period).  From this implantation, the uterus and the embryo form a network of blood vessels that exist only during the pregnancy.  This is called the placenta and is what the umbilical cord is attached to.

The uterus, besides being key to the reproductive cycle, is also important in the sexual response cycle.  It directs blood flow toward the pelvis and outer genitalia during sex. This directed flow of blood happens during arousal and allows for sex to be pleasurable to the woman.  The uterus is also involved in a somewhat rare type of orgasm called, of course, the uterine orgasm.

The uterus is, arguably, the most central organ to not only reproduction but also sexual response.  Take good care of your uterus and go to the gynecologist for your regular check-up!  Have questions or comments?  Let’s hear ’em.

Episiotomy

When I was younger I remember hearing the word episiotomy in relation to childbirth but never really knew what it meant.  As I got older, I heard the word less and less often.  That is until my senior year of college when I got to know the meaning of the word quite well without actually experiencing it myself.  In one of my seminar classes, a classmate (a midwife by day) was telling the class about the term paper she was writing.  It was about the birthing practices of rural Nicaragua.  She worked in a tandem network of midwives both here in the US and in Nicaragua.  She said that the practice of episiotomy in the US was almost completely extinct but that it was still commonly used in Latin America.

In a class of about 11 women and 1 man (poor guy!), we all wanted to know more about this “episiotomy.”  So, in the spirit of that midwife taking her time to explain this practice I hope to impart a better understanding of the practice on you.

I have heard an episiotomy rather brutally and frankly described as cutting the vagina to make it wider for a baby’s head to pass through more easily during birth.  This is basically true but is not necessarily as barbaric as it may sound.  The cut is actually a type of surgery and it is done under anesthesia.

Most Western countries (United States, Australia, and Europe in particular) have moved increasingly away from using the episiotomy because of the complications it can cause.  A birth may progress without any need for the vaginal opening to be wider or the perineum (skin at the back of the vagina) may tear on its own.  This, too, is not as gruesome as it may sound.  A natural “tear” is often much shallower than an episiotomy.  Thus an episiotomy may take longer to heal and cause more complications.

There are two main types of episiotomies:  one is basically a straight, lateral cut from the vagina backward–this is called midline.  The other kind is is called medio-lateral and is cut at more of an angle away from the anus.

While there is certainly a time and a place for an episiotomy (as there is for a Cesarean section), I believe that natural tearing is preferable to episiotomy if possible.  The midwife I mentioned earlier explained this in an example I will never forget.  She took a piece of notebook paper and cut it halfway through with scissors.  “This is an episiotomy,” she said.  She took another piece of paper and tore it half way.  She said, “This is a natural tear.”  The torn piece of paper had all sorts of fibers and extra edges to it that the cut piece of paper didn’t have.  These overlapping bits provide a better opportunity to heal.  (Imagine trying to glue the cut piece of paper back–you couldn’t!  But you could with the torn piece of paper.)

Some studies show episiotomies, especially midline, cause greater complications even after the healing has occurred.  For instance, a woman can have trouble with sexual intercourse–it can be painful due to scarring and her vaginal walls can have trouble becoming lubricated.

There are certain therapies (such as massage and perineal dilation) than can help give the vagina preparation for birth that will make it less likely that a doctor will perform an episiotomy.  In any event, it is yet another complicated decision that a mother must make in the birthing process.  Hopefully this sheds a bit more light on it.  Have questions or comments?  Don’t be shy–dive right in!