A&P II_Female Reproductive

Note: rectum, vagina, and urethra will pierce the pelvic diaphragm on the way to get out. What is interesting is the pelvic diaphragm does not completely occlude or close off the inferior part of the pelvis! There is a gap between the ischiopubic rami. This gap will be closed off by another muscular diaphragm referred to as the ____.

Note: rectum, vagina, and urethra will pierce the pelvic diaphragm on the way to get out. What is interesting is the pelvic diaphragm does not completely occlude or close off the inferior part of the pelvis! There is a gap between the ischiopubic rami. This gap will be closed off by another muscular diaphragm referred to as the urogenital diaphragm.

What are the three basic openings that we have to seal up with muscles?

On the lateral side is the obturator foramen. 2. And then, there is the floor of the pelvis itself and 3. part of this greater sciatic foramen. All of these open areas are filled in by these muscles and they are skeletal muscles which we have voluntary control over (somatic nervous system).

You've just put your hand in female pelvis, what cavity/space am I really in? It is an extension of what?

Peritoneal cavity The greater sac of the peritoneal cavity

What are the 3 parts of the Fallopian Tube?

1. Fimbriae 2. Ampulla 3. Isthmus 4. Intramural Portion The ovary has three parts: the "fingerlike" fimbriae end (the fimbriae are cells that have cilia which during ovulation beat into the tube, allowing the egg to be captured and sucked in). Then there is a wide area called the ampulla which is just a large area which after ovulation when the egg is swept in, the egg will sit in the ampulla for a number of days waiting to fertilize. -Whether it is fertilized or not, after a certain amount of time, the egg will continue its journey by traversing the fallopian tube. -As you get closer to the uterus, it narrows from this wide ampulla to this narrow isthmus, and then that part of the fallopian tube which penetrates the fibromuscular wall of the uterus is called the intramural portion.

Why are the vagina and urethra not oriented straight up and down like the rectum?

Recall that the vagina and the urethra are on an oblique angle, not straight up and down like the rectum, and that's because they must bend anteriorly to get through the other diaphragm (urogenital) to get to the outside world whereas the rectum stays posterior.

The ___ is the most posterior structure piercing the pelvic diaphragm and it stays posterior as it continues on to form the anal canal.

Rectum

So again, the ovary is attached to the broad ligament by the ___, but it's also attached to the uterus by the ____ and to the lateral wall by the ___ which contains all of these great vessels.

So again, the ovary is attached to the broad ligament by the mesovarium, but it's also attached to the uterus by the ligament of the ovary or the ovarian ligament and to the lateral wall by the suspensory ligament which contains all of these great vessels.

There is one part of the uterus where the peritoneum comes up and instead of coming straight to the top, it deviates and forms a little ledge. It is still the peritoneum but a ledge is formed. Attached to that little ledge is the most important part of the female reproductive system. because that ledge is where the ovary is attached.

The Broad Ligament

So, if the true pelvis contains the reproductive organs, what do you think hangs out in the major pelvis?

The GI tract! And some of it actually goes into the true pelvis: the sigmoid colon turns into the rectum.

Back to the floor of the pelvis, and I continue to trot along till I get to the anterior wall. And now there is another bulge. A bulge formed by an organ that lies right behind the pubic symphysis and is a truly retroperitoneal organ. What organ is this?

The bladder

The relationship between the urinary system and the female reproductive system. The ovarian artery is always found medial or lateral? to the ureter at the brim of the pelvis?

The last important slide is this one. This shows you the two important clinical relationships between the urinary system and the female reproductive system. -So here is the kidney, this yellow represents the ureter, and you can note how the ureter runs down the posterior wall into the pelvis and then eventually to the bladder. -Note, the ovarian artery (branch of the aorta) as it goes down to the ovary, at the brim of the pelvis, always lies lateral to the ureter. -This relationship is critical. It never changes. -The ovarian artery is always found lateral to the ureter at the brim of the pelvis. -If you keep following the ureter down, it then meets the uterine artery.

The majority of the superficial innervation comes from what nerve?

The majority of the superficial innervation comes from the pudendal nerve. As I said, "if it's the perineum, it's the pudendal!" So the pudendal nerve is critical. Your old friend, the ilioinguinal and genitofemoral nerves that you've seen already in the anterior abdominal wall, take care of the superior portion of the perineum, again, the same in males. Inferiorly, there are branches that come from cutaneous nerves from the sacral plexus. Mostly pudendal, with other somatic nerves providing a generous amount of cutaneous innervation.

The muscle on the lateral wall of the pelvis closing off the obturator foramen is called the ____.

The muscle on the lateral wall of the pelvis closing off the obturator foramen is called the obturator internus muscle. Note how this muscle does not completely occlude the lateral wall (this obturator foramen!)

When you look at the uterus, it can be delineated into what three parts based on where the uterine tubes open?

1. Fundus 2. Body 3. Anterior and Posterior Fornix The part above the opening of the uterine tubes is known as the fundus, just like the stomach it's this rounded portion. Then you have the very large body. The body on the posterior wall is where implantation will typically take place. Then as you go lower, the body narrows and pushes down through the pelvic diaphragm into the vagina. The vaginal walls come up over that so the uterus, the cervix of the uterus, actually projects down into the vaginal canal. Because the cervix projects down and the walls of the vagina come higher, you get these "recesses, an anterior and posterior fornix. The opening of the cervical portion of the uterus into the vagina is known as the external os, and yes during pregnancy the external os will change shape.

The pelvic diaphragm consists of what two muscles?

1. Levator ani 2. Coccygeus muscle this large triangular shaped muscle called levator ani and right behind it, right under the piriformis and behind levator ani, is the coccygeus muscle. They work together in order to seal off the floor of our pelvis.

And you could look more carefully at the levator ani muscle and see that it is made up of three fairly distinct muscles (or 2 sets of 3 muscles, because there is a left group and a right group!). The three parts of the levator ani and the names are descriptive of origins and insertions which you don't have to remember. What are the 3 distinct muscles that make up the levator ani muscle?

1. Pubococcygeus muscle 2. puborectalis muscle 3. illiococcygeus muscle ------------------- There is a pubococcygeus muscle that goes from the pubis to the coccyx, a puborectalis muscle that goes from pubis, forms a sling around rectum, and joins puborectalis muscle from the other side. And then there's this fan-shaped iliococcygeus muscle,

The Urogenital diaphragm is composed of what?

1. Skeletal muscle 2. Fascial Covering

Describe the Innervation of the Female Pelvis

1. Somatic Part 2. Sympathetic Part 3. Parasympathetic Part How is all this innervated? There are three parts as we know: there is the somatic part which is just regular pain, touch, temperature proprioception as we know from nerves, and then we have the autonomic innervation. So, I don't have to tell you that the external genitalia/perineum is exquisitely sensitive.

When you look at the pelvis, it's got all these holes in it! Why don't the organs just fall out the bottom?

A number of muscular diaphragms were created in order to seal off the spaces and create a foundation for all the organs in the pelvis to lie on. Now we are looking down into the pelvis. And you can see, we don't see any empty spaces! What we do see are muscles.

And what you end up getting is a mixture of preganglionic parasympathetics in the Pelvic Splanchnics, a mixture of postganglionic sympathetics from the chain, mixing together to form appropriately: the huge ____sitting right there in the pelvis. And it will supply innervation to what structures?

And what you end up getting is a mixture of preganglionic parasympathetics in the Pelvic Splanchnics, a mixture of postganglionic sympathetics from the chain, mixing together to form appropriately: the huge inferior hypogastric plexus sitting right there in the pelvis. -And it will supply innervation to almost all the structures in the pelvis, whether male or female. ----------------------------------- NOTES: Remember that the greater, lesser, least and lumbar splanchnic nerves provide fibers that synapse in preaortic ganglia and supply the visceral organs of the digestive tract. For the pelvic organs the sympathetic innervation comes from spinal cord segments T11-L1 with the exception of the ovary and testes which comes from T10-11 due to the fact that they both develop in the thoracic region and then migrate down into the pelvis. Parasympathetic innervation to the pelvic organs comes from the pelvic splanchnic nerves which arise from lateral horn of spinal cord segments S 234. Pain from the pelvic organs typically travels with the pelvic splanchnic and therefore refers to the S 234 dermatomes. Exceptions to this: ovaries, and body and fundus of the uterus, which travel with the sympathetics.

One of the questions that an anatomy exam inevitably asks is, what nerve would innervate the obturator internus muscle?!

And you would think, well the obturator nerve goes right through it, why wouldn't it innervate the obturator internus muscle. Alas, this is not the case. Instead the nerve that innervates the obturator internus muscle is called the nerve to the obturator internus, which is a branch of a large somatic plexus called the sacral plexus. This closes off the lateral wall of the obturator internus.

As the left and right hypogastric nerve makes its way into the pelvis, it is JOINED by ____ nerves coming from ___. These nerves are preganglionic parasympathetics. And they join the postganglionic sympathetics found in the left or right ____ nerve.

As the left and right hypogastric nerve makes its way into the pelvis, it is JOINED by Pelvic Splanchnic nerves coming from S2, S3, S4. The Pelvic Splanchnic nerves are preganglionic parasympathetics. And they join the postganglionic sympathetics found in the left or right hypogastric nerve.

What is the importance of the relationship between the rectouterine pouch and the posterior fornix?

But the relationship between the rectouterine pouch and the posterior fornix is still critical for in vitro fertilization. During in vitro, women are primed with hormones to cause the ovary to develop a lot of eggs at once. But you need to harvest the eggs prior to ovulation in order to do in vitro. And here you can see an ultrasound probe inserted into the vagina, pressing at the posterior fornix, allowing visualization of the ovary, and then pass a needle through the posterior fornix into the ovary to aspirate the eggs.

The bony pelvis consists of what two bones? And each of these bones are composed of what?

Coxal Bones (left and right) And each coxal bone is composed of three smaller bones that have fused during development: 1. the very large ilium, 2. a pubis, and 3. the ischium.

The ovary is covered by what? For one brief moment once a month something does end up in the peritoneal cavity?

Epithelium and thus by definition you are not in the cavity When an egg is ovulated, egg bursts through the epithelium and then it is sitting or lying in peritoneal cavity. Typically the fibriated end of the fallopian tube will suck it right in but sometimes it doesn't -->falls into the rectouterine pouch -the female reproductive system is an open system to the outside world: sperm swims its way into cervix into uterus, sperm goes into fallopian tube to egg, -->leads to ectopic pregnancy Fallopian tubes are open into peritoneal cavity the peritoneum is very vascular so the fertilized egg which is in the peritoneal cavity will implant to the peritoneal cavity BUT also the same way sperm went through, bacteria can also do the same and get PID/peritonitis

External Genitalia The labia minora enclose what is known as the ___. And what two structures that pierce the urogenital diaphragm open into it?

External genitalia. Note: labia majora laterally. Labia minora more medially. The labia minora enclose what is known as the vestibule. And in the vestibule opens the two structures that pierce the urogenital diaphragm: 1. superiorly the urethra and just below it the 2. vagina. Both open into the vestibule! Note the close proximity of the urethra to not only the vaginal canal but also the rectum. Because of the structure of a female compared to a male, women are far more prone to UTIs. Follow the labia minora north (or superiorly) and it will always lead you to the glands of the clitoris (which is homologous in every way to the glans of the penis) and the hood that encloses it.

Describe the Peritoneal Reflections

Here in red is shown the peritoneum sweeping down off the posterior abdominal wall, down to the floor of the pelvis, note how it goes over the posterior surface of the pelvis, over the anterior surface, up over the bladder, and up the anterior wall. -Above is the peritoneal cavity and there is nothing in here! Note the rectouterine pouch of Douglas, the lowest point in a female pelvis. The vesicouterine pouch is obviously higher. I'll come back to this because it is clinically important. Note that the posterior fornix of the vagina and the rectouterine pouch is only separated by a thin layer of smooth muscle and connective tissue

So this is a beautiful picture showing the three key muscles involved in the pelvis and closing off, and how the vagina makes its way through both of those diaphragms.

Here you can see the broad ligament (so I know I am looking at the front), and what has happened is the two leaves of the broad ligament have been opened so you can see what lies between them. Note the cervix projecting into the vaginal canal, external os, but there lying between the leaves of the broad ligament are the neurovascular bundles. You can see the uterine artery running up to take care of the upper part of the cervix, you can see the vein, and also note the structures of the pelvis that we talked about: lateral wall closed off by the obturator internus. Note the dome shaped pelvic diaphragm that the diaphragm needs to go through. And then after bending past that pelvic diaphragm, it then needs to go through the urogenital diaphragm.

How was the adnexa examined before ultrasound?

If I pierce this rectouterine pouch by going through the posterior fornix of the vagina (and in the olden days, a procedure done to examine the adnexa was done using a fiberoptic instrument, and since ultrasound hadn't been invented yet this was the only way to examine the fallopian tubes and ovaries, and the problem with doing this was while it provided a great picture it also has high risk infection into peritoneal cavity, so nobody does this anymore).

Of these three diameters, without question, the conjugate diameter is the most important. How so?

It is a way of determining the opening or diameter of the pelvic inlet. By putting two gloved fingers into the vaginal canal and pressing posteriorly, you can feel the promontory of the sacrum. How far your fingers go in tells you the diameter, and this is important if you're an obstetrician because the fetal head must engage and get past the pelvic inlet. Knowing the diameter of the pelvic inlet and the diameter of the fetal head gives you a pretty good approximation. During parturition, certain hormones are released that allow the relaxation of the sacroiliac joint and the fibrocartilaginous pubic symphysis, allowing the two coxal bones to separate apart a bit allowing the baby's head to get past the pelvic inlet.

What is important about the Greater and lesser sciatic foramen?

It turns out that the greater as well as the lesser sciatic foramen are actually tunnels, roadways, conduits that connect anatomical spaces. If I were to leave the pelvis because I wanted to enter the gluteal region, I would leave through the greater sciatic foramen! So it connects the pelvis to the gluteal region. And if I wanted to leave the gluteal region and enter the perineum, I could do that by going through the lesser sciatic foramen. So the greater sciatic foramen connects the true pelvis to the gluteal region. And the lesser sciatic foramen leads from the gluteal region to the perineum.

What would happen if I opened up the broad ligament?

Just like the mesentery in the GI tract, you would find the neurovascular bundle!

What is the major blood supply tot he uterus?

Major blood supply to the uterus is the uterine artery off the internal iliac. It supplies not only the body but it also goes into the mesosalpinx to supply the uterine tubes as well as the ovary. -In addition, that uterine artery will come and supply blood to the upper part of the vagina. -So this uterine artery is very important, and important to be careful when you do a hysterectomy and remove the uterus and ligate the uterine artery.

Ledge that holds ovary

Mesovarium

The most posterior and superior muscle of the pelvis is the?

Most posterior and superior, there is a muscle that starts with a P and it's called the piriformis muscle. The most superior aspect of our pelvis is closed off by the piriformis muscle. The piriformis muscle leaves the pelvis through the greater sciatic foramen to enter the gluteal region. The obturator internus muscle leaves through the lesser sciatic foramen. Both the piriformis and the obturator internus will insert on the femur (the largest and strongest bone in the body) and do the lower limb.

This is an artist's depiction of what happens during ovulation. Here you can see the ovary, the fimbriated end, coming up during ovulation. The egg is being ovulated. What you don't appreciate is that the egg is covered by incredibly sticky cells called the ____, and the cilia located on the cells of the fimbriae, all they have to touch the sticky cumulus cells and it draws the whole thing into the ova duct.

Next diagram is an artist's depiction of what happens during ovulation. Here you can see the ovary, the fimbriated end, coming up during ovulation. The egg is being ovulated. What you don't appreciate is that the egg is covered by incredibly sticky cells called the cumulus oophorus cells, and the cilia located on the cells of the fimbriae, all they have to touch the sticky cumulus cells and it draws the whole thing into the ova duct. So the egg is sitting deeper in, but it's covered by the cumulus cells. This whole process almost always ensures that the egg is swept into the oviduct, but sometimes it misses and falls into the peritoneal cavity.

Is the heart in the pericardial cavity? Is the lungs in the pleural cavity?

Nope -they are just a space Because it is covered by visceral peritoneum But Uterus is covered in peritoneum

These pelvic muscles are what type of muscle and are innervated by what part of the nervous system?

-Skeletal muscle -thus innervated by our Somatic NS, typical spinal nerves You have control over these skeletal muscles.

There is a little opening here which allows a very important nerve that lies on the posterior abdominal wall to leave the pelvis and enter into our thigh. This opening is referred to as the ___, and take a guess at what you would name the nerve that goes through that opening?

-The Obturator Foramen -You guessed it, the obturator nerve. -The obturator nerve leaves the pelvis and enters our thigh by going through the obturator foramen (or the obturator canal actually).

And because it forms a boundary between two anatomical areas, the pelvic diaphragm has dual innervation. How so?

-The superior aspect is done by branches of the lumbosacral plexus. -And the inferior side (@ the roof of the perineum) is done by the pudendal nerve (which does 99% of skeletal muscle done in the perineum). -So the pelvic diaphragm is unique in that it is innervated by two nerves depending on superior or inferior surface.

The ureter artery always runs above or below? the ureter?

-The uterine artery always runs OVER the ureter. -You can always remember that by the little diddy, "water runs under the bridge." -The bridge formed by the uterine artery and the ureter carrying urine (the water), runs under.

What must a surgeon do or becareful with when doing a hysterectomy and oophorectomy in regards to the vessels?

-When a completely hysterectomy and ovariectomy must be done, you need to be careful that the uterine artery and ovarian artery are cut and ligated, and NOT the ureter. -If there is a mistake in a hysterectomy, it is because the surgeon did not cleanly isolate the ureter.

Do you think female immune system recognizes the sperm as foreign?

-Yes, it will attack it -yet the vast majority of women do not make antibodies to sperm Why when faced with something foreign does your immune system not respond to it

Now let's take a look at the organs and blood supply. Here we have a picture of our uterus (232). On the right side the peritoneum is intact and on the left side it has been removed. You can see that the ovary is attached to the uterus by the __. and it is attached to the lateral wall of the pelvis by what's called a _____.

-ovarian ligament You can't see the ledge of the peritoneum, aka the mesovarium, because the ovary is attached to it. -But it is attached to the uterus by this ovarian ligament and it is attached to the lateral wall of the pelvis by what's called a suspensory ligament of the ovary. And if you were to open up and strip away the peritoneum, you would see that the suspensory ligament is kind of important because it contains the neurovascular bundles: the ovarian artery, the vein, autonomics, lymphatics...etc.

What are the 3 diameters of the pelvic inlet?

1. Conjugate Diameter 2. Transverse Diameter 3. Oblique Diameter -The pelvic inlet (the way into the female pelvis) has a number of diameters. -There is an anterior-posterior diameter which goes from the pubic symphysis to the promontory of the sacrum known as the conjugate diameter. -There is also a diameter that measures the left to right opening called the transverse diameter. -And another one you might read about in some textbooks is called the oblique diameter. -It basically goes from the sacroiliac joint of one side to the iliopubic eminence (raised part of the bone on the ileum) on the contralateral side.

Describe the dual blood supply of the ovary

The ovary actually has a dual blood supply: the ovarian artery (which we know from the abdominal aorta) and another big blood supply to the female reproductive system: the uterine artery which is a branch of the internal iliac. The uterine artery will reach the uterus at about the level of the cervix, run between the leaves of the broad ligament to supply the uterus, and then it will branch to provide blood to the ovary and tube. The ovarian artery (from the abdominal aorta) supplies the ovary and there is also a branch going to the uterine tube. So this anastomosis is important! Because the ovarian artery comes from the abdominal aorta and the uterine artery comes from the internal iliac, aka both HUGE sources of blood both of which supply the entire reproductive system. And as you know, during pregnancy, with the formation of the placenta, it requires an enormous amount of blood which is provided by this anastomosis!

The perineum is defined as? Describe the innervation to the perineum?

The perineum is defined as the space between the pelvic diaphragm forming the roof and the gluteal region forming the floor. And the perineal region is filled with a lot of fat as you well know.

Note that the pelvic diaphragm is dome-shaped (rounded) at the bottom. The perineum is this space between the ___ above and the ___ below. Also remember that the perineum is filled by an enormous amount of ___, which is important for another reason.

The perineum is this space between the rounded pelvic diaphragm above and the gluteal muscles below. Also remember that the perineum is filled by an enormous amount of fat, which is important for another reason. So this is the structure of the pelvic diaphragm and how we have to bend through the urogenital diaphragm in order for the urethra and vagina to exit.

What is the lowest point in the female pelvis?

The recto uterine pouch -clinically important because it is where infections will fester and grow

The rest of this msucle is referred to as the ____. And what does it provide?

The rest of this muscle is referred to as the pelvic diaphragm. And it provides most of the foundation that closes off the pelvis.

MOVE THE PERITONEUM Object of game: move the peritoneum from one side to another. One rule: As we move the peritoneum from one side of the screen, you are not permitted to go through the structure. Can go around but not through. Peritoneum comes sweeping down off of the posterior wall of screen, then runs along the floor of the pelvis working its way to the other side of screen, and stops and turns around and looks at posterior wall and notes that behind the peritoneum there is a bulge in the peritoneum. This organ is coming down that posterior wall and makes its way to midline so it can get into the pelvis. What organ forms this bulge that I see behind this peritoneum on the posterior wall.

The sigmoid colon becoming the rectum

The superior hypogastric plexus containing postganglionic sympathetics makes its way towards the sacrum down into the pelvis. As it makes its way, this little obstruction formed by the ___ in the beginning of the rectum prevents the superior hypogastric plexus of nerves from continuing down, and so it divides into a left and right hypogastric plexus. And this simply means that half goes to the left and half goes to the right, we are bilateral afterall!

The superior hypogastric plexus containing postganglionic sympathetics makes its way towards the sacrum down into the pelvis. As it makes its way, this little obstruction formed by the sigmoid colon in the beginning of the rectum prevents the superior hypogastric plexus of nerves from continuing down, and so it divides into a left and right hypogastric plexus. And this simply means that half goes to the left and half goes to the right, we are bilateral afterall!

The sympathetics are coming downnnnn into the pelvis. There are a lot of postganglionic fibers leaving the sympathetic chain as you know, they congregate around the aorta, and then they begin to form something that is called the ____

The sympathetics are coming downnnnn into the pelvis. There are a lot of postganglionic fibers leaving the sympathetic chain as you know, they congregate around the aorta, and then they begin to form something that is called the superior hypogastric plexus.

What type of muscle makes up the urogenital diaphragm? And it is innervated by what nerve?

The urogenital diaphragm is composed of skeletal muscle and a fascial covering. When you peel away the inferior fascia of the urogenital diaphragm, you see the muscles that make up the urogenital diaphragm. This is skeletal muscle! Both the urethra and the vagina leave the pelvis through the pelvic diaphragm but then BEND to get through the urogenital diaphragm. This is skeletal muscle as I've said, it's in the perineum, and therefore it is innervated by the nerve that does 99% of skeletal muscle in the perineum: the pudendal nerve. How do I know it is skeletal muscle? Because I have control over it. When you stop urinating, you are squeezing the skeletal muscle surrounding the urethra closing off the flow of urine.

Moving along the floor of pelvis, i am right in the middle of the female pelvis. I found an obstruction. What obstruction have I run into right in the center of a female pelvis? Now remember the rule: I can't go through it. So what do I do?

The uterus Have to climb up the wall of the uterus over the top and down the anterior wall to get back to the floor of the pelvis.

What are the different ways to treat uterine prolapse?

There are a number of ways you can treat this, depending on the patient's wishes and age, you can obviously do a hysterectomy, or you could push the contents back up and insert a pessary. A pessary is very similar to a diaphragm you would use for birth control. It holds the contents in place and you visit a physician every 6 months or so to replace it. Or now you can also do surgery to tighten up the uterus and ligaments to hold it in place. So, a prolapsed uterus is where the pelvic diaphragm weakens and ligaments give out and you can't support the weight.

There is a procedure called a ____ where a contrast dye is placed through the cervix into the uterus and it fills the uterus and x-rays are taken a certain amount of time after the injection of the dye. The dye continues out of the uterus to line the uterine tube, and here you can see the dye spilling out into the peritoneal cavity (on both sides), so you know the tubes are patent. So the problem with conception is not related to the uterine tubes being scarred in any way.

There is a procedure called a uterosalpingography where a contrast dye is placed through the cervix into the uterus and it fills the uterus and x-rays are taken a certain amount of time after the injection of the dye. The dye continues out of the uterus to line the uterine tube, and here you can see the dye spilling out into the peritoneal cavity (on both sides), so you know the tubes are patent. So the problem with conception is not related to the uterine tubes being scarred in any way.

What is the way IN to the pelvis and the way OUT

There is a way IN to the pelvis: the pelvic inlet, and while you can't appreciate this in 2D, there's a way OUT of the pelvis called the pelvic outlet. Most of us have made that journey at one time or another in our lives.

The vagina and the urethra, after going through the pelvic diaphragm, are a little bit different. How so?

They bend anteriorly because they come out or exit through the urogenital diaphragm to open up into the outside world. The other important thing to remember about the urogenital diaphragm is that it separates two anatomical spaces: the pelvis above and the perineum below.

This is a parasagittal view of the uterus. Remember how I said the peritoneum comes up the posterior wall over the anterior wall and this is how you get your rectouterine and vesicouterine pouches. At a point off the midline, that continuous piece of peritoneum forms a ledge that goes up and over. Because of this ledge formed by this broad ligament (this "____"), the large broad ligament is divided into what two parts?

This is a parasagittal view of the uterus. Remember how I said the peritoneum comes up the posterior wall over the anterior wall and this is how you get your rectouterine and vesicouterine pouches. At a point off the midline, that continuous piece of peritoneum forms a ledge that goes up and over. Because of this ledge formed by this broad ligament (this "mesovarium"), the large broad ligament is divided into two parts: 1. a mesosalpinx (which contains our uterine tubes) and the rest is the 2. broad ligament. Note the ovary attached to the mesovarium on the posterior wall right over the rectouterine pouch.

What else can the uterine artery and internal iliac supply?

This is just for me to remind you that the uterine artery can supply branches to the vagina and also the internal iliac can directly supply blood to the vaginal canal: each one of us is variable.

Try to remember: if it's going into the GI tract (sigmoid, rectum), those preganglionic parasympathetics will synapse in the ___ of the organ whereas other preganglionic parasympathetics are going to synapse IN the ___, and those postganglionic parasympathetics will then go to erectile tissue of the penis, the clitoris, and the bladder.

Try to remember: if going into the GI tract (sigmoid, rectum), those preganglionic parasympathetics will synapse in the WALL of the organ whereas other preganglionic parasympathetics are going to synapse IN the inferior hypogastric plexus, and those postganglionic parasympathetics will then go to erectile tissue of the penis, the clitoris, and the bladder.

Because of presence of the uterus, what two spaces have been created?

Two valleys 1. One between the uterus and rectum (the rectouterine pouch of douglass) 2. One between uterus and bladder (vesicouterine pouch)

How does the orientation of the uterus change before and during pregnancy?

Typically, the uterus is tightly bent over the bladder in an anteflexed and anteverted position. But during pregnancy, the uterus has to grow to accommodate the fetus so it tends to get more vertical as it goes up into the abdominal cavity. As a consequence of that, more pressure is put on the pelvic diaphragm which is supporting the uterus. After childbirth, the uterus shrinks back to almost its original size but it never again is in that tight anteflexed and anteverted position. It's always a little bit raised. And on top of that as women age, the pelvic diaphragm begins to weaken a little bit. The ligaments responsible to assist in holding the uterus begin to weaken and wither also. A lot of pressure is put on the pelvic diaphragm, the primary support of the uterus. Hence, the importance of kegel exercises during pregnancy to exercise that pelvic diaphragm. And what happens is, as the uterus gets more vertically, the pelvic diaphragm can no longer support the weight. . So what begins to happen as women age is the uterus stands more vertical, you lose tone in the pelvic diaphragm and the uterus begins to push out the vaginal canal. This is known as a prolapsed uterus.

Clinical Correlations

Upper left: uterus, vaginal canal, bladder, rectouterine pouch, rectum. Note that the rectouterine pouch is the lowest point in the female pelvis (much lower than the vesicouterine pouch) and note the proximity of the pouch to the posterior fornix of the vagina. If I wanted to put a syringe into this rectouterine pouch, I only have to go through a small amount of tissue here. This image shows a nulliparous woman who has not given birth.

Uterine Fibroids

Uterine fibroids are the most common benign tumors in women. -Half of women over age 50 have fibroids. -If you are younger, you can see why having fibroids might be a problem in implantation (in having a baby), especially if they are on the internal posterior wall of the uterus. -Sometimes these fibroids can grow to the size of a grapefruit and press on the nerves on the floor of the pelvis, i.e. the sciatic nerve, and women will experience sciatica not due to the disc space but due to the pedunculae and size of the uterine fibroids. -Very common, these are stimulated by estrogen, and will begin to shrink postmenopause.

What are the notches in the posterior aspect of the pelvis? What are the two ligaments associated with these notches? What is important about these notches?

When you look to the back, you can see there are these notches in the pelvis: -greater and lesser sciatic notch. What is important about the notches is that because of the presence of two large ligaments (anterior a small sacrospinous ligament and most posteriorly a large, strong sacrotuberous ligament), these two notches in the bone are converted into foramina: the greater and lesser sciatic foramen.

Now, in the olden days when a couple couldn't conceive, it was of course felt that the problem has to lie in the female reproductive system because as we know males are so perfect in every way they could never be wrong. As part of a workup you would do to determine problems in the female reproductive system (and by the way, problems in conception are 50/50 male-female), what is one of the first things you do?

after the endocrine workup you make sure ovulation is actually occurring, the next question is, are the uterine tubes patent? Are they open? Because if the egg is ovulated and swept into the oviduct, it has to make its way into the uterus! So could these tubes be blocked? Could there be an infection? PID? Gonorrhea?

The levator ani muscle has its origin from this white thick condensation of fascia on the surface of the obturator internus muscle called the ___.

has its origin from this white thick condensation of fascia on the surface of the obturator internus muscle called the arcus tendineus (labeled TA on the diagram). The arcus tendineus is so strong, it forms an attachment for the muscles that make up the pelvic diagram. So again, the pelvic diaphragm consists of two muscles: coccygeus muscle and levator ani (has 3 divisions: pubococcygeus, puborectalis forming a sling around the rectum, and iliococcygeus which has an extensive origin from the arcus tendineus). Levator ani plus the coccygeus is the pelvic diaphragm.

And the important thing you are looking at as we look down into the pelvis, this very large group of muscles, is known as the ____.

pelvic diaphragm.

What is interesting about the pelvis is how it is divided up. If you place your hand over the pelvic inlet, you divide the pelvis into what two parts?

the part above the pelvic inlet is larger and we refer to it as the major pelvis. The part below is smaller and we call this the true pelvis. It's called the true pelvis because lying within it are the contents of the female reproductive system.

The coccygeus muscle + levator ani = ____.

the pelvic diaphragm! They work together in order to seal off the floor of our pelvis.

Difference between sacroiliac joint and pubic symphisis

the sacroiliac joint is a synovial joint while the pubic symphysis is a fibrocartilaginous joint.