Anatomy of the Female Reproductive System (Nursing)

00:01 Now, let's look at some of the structures of the female reproductive system.

00:07 We'll start by looking at the gonad which in the lack of a Y chromosome will grow into an ovary.

00:14 And here, we see the ovary is very closely associated with the uterine or fallopian tube which connects to the uterus.

00:25 The uterus eventually narrows down to something called the cervix which is continuous with the vagina.

00:33 And together, these will be the equivalent of what we would call the female reproductive ducts.

00:39 If you think about the uterus and how much it grows during pregnancy, it makes sense that there's going to be a lot of ligaments that keep it held in place within the pelvis.

00:52 For example, we have the uterosacral ligaments that do just what the name says, connects the uterus to the sacral bones or this sort of distal portion of the vertebral column that makes up the posterior portion of the pelvis here.

01:10 There's also the pubocervical ligament which connects the cervical area to the pubic bone.

01:16 The cardinal ligaments which are more transversely oriented and connect the cervical ligaments to some of these uterosacral ligaments.

01:25 We also have a very wide one called the broad ligament that we're going to look at in greater detail.

01:32 We also have one that doesn't look as supportive and that's the round ligament.

01:38 That's because the round ligament isn't really so much a supportive structure as it is a remnant of something called the gubernaculum which is this embryologic structure that sort of guides the descent of the ovary during development.

01:54 And it connects to the labia. So, the broad ligament as the name implies, it's very broad.

02:02 And, so, there's a lot of structures within this that we're going to want to point out.

02:06 It's covered in peritoneum just like any other structure in the abdominal pelvic cavity and here, we see the broad ligament is basically a wide sheet covered in peritoneum.

02:22 Its upper border may be free but the lower borders are continuous and attached to the surrounding abdominal pelvic wall through the peritoneum.

02:35 So, it's a lot like the other structures we learned about in, for example, the abdomen that have connections via peritoneum to the surrounding wall that give it some support.

02:46 We'll break down certain portions of the broad ligament depending on where we are.

02:53 So, the portion of broad ligament that's associated with the fallopian or uterine tube is going to be called the mesosalpinx.

03:01 Salpinx, whenever you hear that, that's another term for the tube.

03:06 So, for example, salpingectomy is cutting out a tube, the fallopian tube.

03:12 The portion connecting to the ovary will be the mesovarium.

03:18 The portion connecting to the majority of the uterus is the mesometrium.

03:24 Metrium is going to be a suffix that relates to the uterus.

03:30 Let's take a look at a sagittal section and see how these organs sit related to other ones.

03:39 For example, the distal portion of the large intestine. The rectum here sits most posteriorly.

03:46 The uterus is going to sit just anterior to the rectum here.

03:52 And the uterus, again, is going to be continuous with the vagina.

03:57 Sitting anterior to both is going to be the bladder and in this sagittal view, you can see just how compressed the bladder may be during pregnancy as the uterus becomes enlarged throughout the course of a pregnancy, it's going to be compressing the bladder against the pubic bone.

04:18 Because we see here in the midline, this is the public symphysis or this fibrocartilaginous structure that connects the two halves of the bony pelvis.

04:27 Again, the pelvic cavity is really continuous with the abdomen, so, we sometimes say abdominal pelvic cavity.

04:34 So, everything here is still lined by peritoneum.

04:39 And because it's all lined by peritoneum, we see that there's actually a little tiny space between the bladder and the uterus.

04:48 And we will call that tiny little space the vesicouterine pouch.

04:52 Vesico is just another term for bladder.

04:57 Posteriorly though, we have another pouch called the rectouterine pouch.

05:03 Again, it's the space between the rectum and the uterus and the name's very descriptive and tells you exactly where that is.

05:09 For example, if you were to say there's an abscess in the rectouterine pouch, that will be very descriptive and tell you exactly where that's located.

05:16 But unfortunately, it's very commonly used by its eponym, the Pouch of Douglas.

05:22 So, you want to be aware that that is the other name for this space.

05:26 If we were going to take off some of the peritoneum of the broad ligament, we could see the ovary and its associated fallopian tube much more clearly here.

05:36 We actually see the fallopian tube, while it does drape over the ovary, it's not actually holding it in place.

05:43 It's just in close approximation with it. The ovary is actually held if you will, by the utero-ovarian ligament and the suspensory ligament but not the fallopian tube.

05:57 It does have a very close relationship but not one where it's directly attached for support.

06:07 So, let's take a look at that in greater detail. So, if we were to look at it in cross-section here in sort of a frontal plane, we can see why and how the fallopian tube sits over the ovary in the manner that it does. So, in the ovary, there are many follicles of different types, all the way from primordial that are there from prior to birth, to primary, secondary, and even tertiary follicles or mature follicles that are ready for ovulation.

06:40 And because follicles are all around the ovary, the fallopian tube isn't fixed in one spot.

06:46 Rather, it uses signals to locate the follicle that's most likely to rupture during ovulation and center itself over that area.

06:57 That way, during the process of ovulation when the egg or the oocyte ruptures through, the fallopian tube will be right there in place to catch it.

07:11 After the oocyte has ruptured and ovulation is complete, the follicle doesn't just disappear, it actually turns into something called the corpus luteum and that corpus luteum is going to secrete special hormones that are going to help facilitate the process of gestation, and therefore, is called progesterone. And so it'll have an interesting impact on the inside layer of the uterus that we'll look at later.

07:43 The fallopian tube portion that sits over the ovary and sits there to sort of pick up this recently ruptured oocyte are the fimbriae.

07:54 They're little finger-like projections and they're going to lead into something called the infundibulum which in turn, is going to have a wide portion called the ampulla.

08:06 And then, a narrow part where it connects to the uterus called the isthmus.

08:12 The uterus itself has this very wide portion that is the portion that projects into the abdominal pelvic cavity called the fundus of the uterus.

08:24 And then, the narrow part inferiorly where it's about to join into the vagina is the cervix.

08:31 Everything else is composed of the body of the uterus.

08:36 The uterine wall has a very thin inner lining called the endometrium.

08:42 And although it's very thin, functionally speaking in terms of implantation of developing blastocyst or zygote, the endometrium is going to be the most important portion for that.

08:56 But the thickest portion is going to be the smooth muscle underneath it called the myometrium.

09:03 And then, superficially, another thin layer continues with the peritoneum which is going to be the perimetrium.

09:12 So, let's look at this connection between the ovary and the uterus a little bit more closely.

09:18 So, ovulation again is going to result in this unfertilized oocyte being picked up by the fimbriae of the fallopian tube.

09:30 And in the fallopian tube, will get fertilized by sperm.

09:36 And this process of moving is going to be facilitated by some structures within the fallopian tube so that as this fertilized cell is dividing into more and more cells, eventually becoming something called a blastocyst, it will reach the uterine cavity at this stage called the blastocyst so that it can implant into the endometrium.

10:04 Now, the endometrium, because this is where the blastocyst is going to implant, is going to look different at different stages during the menstrual cycle.

10:14 So, if we were to start at the premenstrual or the thickest portion of the endometrium, we would have the menstrual portion of the endometrium where it's actually lost or shed.

10:27 The superficial most portion of this endometrium called the functional layer will be shed but the baso layer will remain so that it can regenerate during the ongoing process of the menstrual cycle.

10:43 The post-menstrual cycle, this will again, it will grow or recapitulate the functional layer under the influence of estrogen hormones.

10:53 And then, after ovulation, that remaining follicle we said turn into a corpus luteum, it will secrete something called progesterone which will make the endometrium grow even more into something called secretory endometrium and will be very big, very thick, and ready for implantation. And if implantation doesn't occur, then, the cycle starts over again with menstruation.

11:23 Now, the fallopian tube itself is going to undergo peristalsis as well as have a lot of ciliated cells in its lining to help move the fertilized egg towards the uterine cavity.

11:39 Unfortunately, sometimes, it's not able to do that and it will implant too early.

11:46 For example, in the fallopian tube and if it implants in the fallopian tube, it's outside of the usual area.

11:54 So, we would call that an ectopic pregnancy. Ectopic is a term used in a lot of senses, it just means outside the usual area.

12:05 The fallopian tube is the most common area of an ectopic pregnancy but because the fallopian tubes are not directly attached to the surface of the ovary, sometimes, you can even have ectopic pregnancies where they fall out of the fallopian tube and into the surrounding abdominal cavity and even have an abdominal ectopic pregnancy.