Anatomy of the Uterus

00:01 Now, let's turn our attention to the uterus and the various structures of the uterus, and its association with the peritoneum within the pelvic cavity known as the broad ligament.

00:12 So here we can see the uterus.

00:14 We have a body of the uterus, and we have the cervix.

00:18 The cervix remembers that part that protrudes into the vagina.

00:23 We also have a fundus of the uterus.

00:26 And here as it's giving rise laterally to the uterine tubes, we have the uterine horns.

00:31 Here we can see the uterine tubes or the fallopian tube we can see here.

00:36 And here we can see the cavity of the body of the uterus.

00:40 Remember, the uterus is going to be a very thick, strong structure.

00:43 And the cavity here is where that growing embryo and fetus is going to be located.

00:50 We can see that the cavity of the uterus tapers down as it passes towards the cervix.

00:55 So here we can see the isthmus.

00:56 And then we have two openings - an internal and an external cervical os, and now the openings either side of the cervical canal.

01:05 So we have the vaginal canal, the vaginal vault.

01:08 Sperm will then be expelled into that vaginal vault upon ejaculation, and sperm will have to make their way through the external cervical os to enter the cervical canal of the cervix.

01:19 And then pass through the internal cervical os before they go into the main body of the uterus, the cavity of the uterus.

01:26 Then they will pass into the respective uterine tubes, where they may encounter a oocytes, an egg that has been expelled from the ovary.

01:37 So here, let's have a look at the various layers of the uterus.

01:40 The innermost layer of the uterus is the endometrium.

01:44 The main muscular layer is known as the myometrium.

01:47 And then the outer layer is known as the perimetrium.

01:50 And that layer is in close position to the peritoneum, which we'll come to in a moment or two.

01:56 So we have three layers that make up the structure of the uterus.

02:00 Endometrium, that inner layer.

02:02 That layer often comes away on a monthly cycle when females have their period.

02:07 And then you have the main substance of the uterus, which is the myometrium, and then the outermost layer, which is the perimetrium.

02:13 In close association with the peritoneum.

02:16 Let's have a look at the various positions of the uterus and the vagina, which we can see here.

02:21 So again, a sagittal section through the uterus, vagina, and bladder.

02:25 Bladder positioned anteriorly.

02:27 And we can draw a straight line and axis of the vagina here.

02:32 We can also draw a straight line as the axis of the cervix here.

02:35 And another straight line is the axis of the uterine body, which we can see here.

02:40 And these three lines help us to determine and describe the relative position of the uterus towards the bladder.

02:48 This would be your typical kind of textbook view of the position of the uterus over the bladder.

02:54 But this isn't always the case.

02:56 Here we have the uterus lying over the top of the bladder.

02:59 And we have this angle of anteversion.

03:02 So the angle of the axis of the vagina and the cervix is the angle of anteversion.

03:08 And you can see in this case, the uterus is anteverted.

03:12 Here, we can also have the angle of flexion of the body of the uterus.

03:17 And this occurs between the axis of the cervix and the axis of the uterine body.

03:22 And we're going to see the body of the uterus here is anteflexed.

03:26 You can then imagine that if the uterus took a slightly more posteriorly orientate position.

03:32 We can have retroversion of the cervix.

03:35 So again, the angle of the vagina and angle of cervix, if that is moved backwards, we have a retroverted cervix in relation to the vagina.

03:46 And then you can also have a retroflexed body of the uterus, where the body of the uterus is tipped posteriorly in relation to the axis of the cervix.

03:55 So these positions of the uterus can occur in a wide range of females.

04:00 The descriptions can vary, not necessarily what you would see in the textbook.

04:06 But here we're going to see a number of positions that the uterus can assume within the pelvis.

04:12 Now, let's have a look at the relationship of the uterus to his neighboring structures.

04:16 So first of all, we have the fundus of the uterus and that is running up and down against the coils of the small intestine within the abdomen.

04:24 The anterior surface here is running alongside the superior surface of the bladder.

04:30 The posterior surface we can see of the uterus is running alongside the sigmoid colon, and also the rectum forming that rectouterine pouch.

04:38 And we can also there for details see the vagina position between the bladder and rectum.