This phase is characterized by the activity of the corpus luteum, which produces progesterone. The signs of estrogen stimulation subside and the corpus luteum starts to form. The uterine lining begins to appear. In the absence of pregnancy the diestrus phase (also termed pseudo-pregnancy) terminates with the regression of the corpus luteum. The lining in the uterus is not shed, but is reorganized for the next cycle.
WK 5 L 1 Ovarian Dysgerminoma Three-dimensional c olor Doppler study of the left ovary showing a whorled pattern of extensive vascularity within the ovarian mass. A feeding vessel is clearly shown. The feeding vessel, lack of a central cyst, and generalized distribution of vessels distinguish this structure from a physiologic corpus luteum.
If a conceptus implants, the corpus luteum grows even bigger, to form the so-called corpus luteum of pregnancy. If no pregnancy occurs, the corpus luteum shrinks dramatically to become a corpus albicans (visible as white scars)
The female reproductive system is freakin' cool. That's all I'm saying. What is the corpus luteum, and how does it work? What is a corpus luteum cyst? What is corpus luteum deficiency? All the answers here.
Prostaglandin F2α (PGF2α, dinoprost [INN]) is a naturally occurring prostaglandin used in medicine to induce labor and as an abortifacient. In domestic mammals, it is produced by the uterus when stimulated by oxytocin, in the event that there has been no implantation during the follicular phase. It acts on the corpus luteum to cause luteolysis, forming a corpus albicans and stopping the production of progesterone.
The corpus luteum also can be recognized by TVS. It can exhibit any of a variety of internal structures and echo patterns, due to the multitude of shapes of the blood or clot that can be seen within it (Figure 3). FIGURE 3 Corpus luteum A–C. Gray-scale, color Doppler, and power Doppler images, respectively, of a typical corpus luteum. B and C show the enveloping vessels, or “ring of fire.” D. A rather typical gray-scale appearance with a mesh-like, linear internal texture. E. A common…