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.
Uterus Size During Pregnancy: First Trimester. Around 12 weeks pregnant, the uterus is the size of a grapefruit and starts to grow up and out of the your pelvis, but still fits within it. If you are carrying twins or multiples, your uterus will start growing and stretching sooner.our uterus grows exponentially during pregnancy. Think about blowing up a balloon and thatâs basically what your uterus does during pregnancy. Before pregnancy, the uterus is about the size of an orange and is situated deep in the pelvis.