Endometrial Cycle (Nursing)

00:01 So, now, let's move on to the very last cycle.

00:04 The endometrial cycle.

00:06 Now this cycle has four phases.

00:08 Don't worry, because again, the words tell us exactly what's going on.

00:13 The four phases include the proliferative phase, the secretory phase, the ischemic phase, and the menstrual phase.

00:22 So, let's look at what's going on specifically in the uterus or the endometrial lining.

00:28 Because over the course of the menstrual cycle, the lining is going to change in thickness.

00:33 So, let's see how that goes.

00:35 In the very first part of the endometrial cycle, the proliferative phase...

00:40 let's stop right there.

00:41 What does the word proliferative make you think of? Something growing.

00:47 Exactly.

00:47 So, think about the fact that the endometrium must become thick in order to be prepared for a potential fetus. Yes? So, in the proliferative phase, the cells are dividing and the uterus is becoming thick over that first part of the cycle.

01:03 Then the next thing that happens is we have a corpus luteum.

01:08 So corpus luteum, if you'll remember produces progesterone, and its job is to stabilize the endometrium.

01:14 So, it's great that the cells are there, and it's proliferative, and it's thick, but we have to have a way to maintain its presence.

01:21 So, there are spiral arteries that help to keep the endometrium in place and progesterone helps to do that.

01:28 So think about secretions.

01:31 And we're secreting progesterone, and other things to keep the endometrial lining in place.

01:38 So, that is the secretory phase.

01:41 So, if we don't get a message from a potential pregnancy in terms of HCG, then our corpus luteum begins to degenerate, and we're going to lose some of that progesterone, and we move into this period of ischemia.

01:54 And as we move into this period of ischemia in the endometrial cycle, the spiral arteries begin to sort of retract, and as they retract, the lining of the uterus is going to begin to sort of die off a little bit.

02:06 And then as we move into the menstrual phase, then we're going to slough off that lining.

02:11 So, think about that.

02:12 Menstrual phase of the endometrial cycle, and sloughing off of the cells.

02:17 Does that make sense? Hopefully, so.

02:20 So, let's again look at the hormones in relationship to the endometrial cycle.

02:25 So, let's start with progesterone.

02:27 So, thinking about how progesterone predominates in the second half of the cycle, it's responsible for maintaining the lining of the uterus.

02:36 And so you can see that after ovulation, progesterone levels go up, right? So, it stabilizes the endometrium.

02:43 But the estrogen or the estradiol is what's responsible for creating thickness and so the estrogen levels are going to be elevated in the proliferative phase.

02:53 Can you see that now? Great.