Fimbriae (common pili) and flagella on the surface of bacterial cells. Left: dividing Shigella enclosed in fimbriae. The structures are probably involved in the bacterium's ability to adhere to the intestinal surface. Right: dividing pair of Salmonella displaying both its peritrichous flagella and its fimbriae.
Relaxin's peak is reached during the 14 weeks of the first trimester and at delivery. It is known to mediate the hemodynamic changes that occur during pregnancy, such as increased cardiac output, increased renal blood flow, and increased arterial compliance.
Third Trimester. Around 28 weeks, the home stretch begins. Many women feel Braxton-Hicks contractions during this time, which is just the uterus's labor preparation. While your body prepares itself, it's a good idea to prepare your mind, too, especially if this is your first baby.