性器官-女性性器官
The Sex Organs - The Female Sex Organs

月经周期：3相月经周期 I

在一些科学教科书里，月经周期通常被划分为2、3、4或更多的不同的阶段。对目前实际运用来说，将它划分成3期似乎是合适的。I

3相月经周期
(周期第一天至月经最后一天所见的子宫内膜）
 

1. 排卵期子宫内膜  子宫内膜在月经后开始生长。
2. 植入期子宫内膜  子宫内膜为胚泡的植入做好了准备。
3. 月经期子宫内膜  如果没有植入发生，子宫内膜破溃并排出月经。

图例： A. 子宫内膜； B. 子宫颈粘液栓； C. 破溃子宫内膜开始排出； D. 消除粘液栓的区域。

The Menstrual Cycle: The Three Phases of the Menstrual Cycle I

In scientific textbooks, the menstrual cycle is usually divided into two, three, four, or more different phases. For our present purposes, a division into three phases seems adequate.

The Three Phases of the Menstrual Cycle
(Seen as beginning after the last day of menstruation)
 

1. Preparing for Ovulation The endometrium begins to grow after menstruation.
2. Preparing for Implantation The endometrium is becoming ready for the implantation of a blastocyst.
3. Menstruation If no implantation occurs, the endometrium breaks down and is discharged in menstruation.

Key: A. Endometrium B. Cervical mucus plug C. Detached endometrium being discharged D. Unplugged area.