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In obstetrics, position is the orientation of the fetus in the womb, identified by the location of the presenting part of the fetus relative to the pelvis of the mother. . Conventionally, it is the position assumed by the fetus before the process of birth, as the fetus assumes various positions and postures during the course of chil
Pregnant women have a decreased perception of balance during quiet standing, which is confirmed by an increase in anterior-posterior (front to back) sway. [41] This relationship heightens as pregnancy progresses and significantly decreases postpartum. To compensate for the decrease in balance stability (both actual and perceived), stance width ...
Sacrum posterior (SP)—the buttocks face posteriorly. Shoulder presentations with transverse lie are classified into four types, based on the location of the scapula (shoulder blade). This presentation needs to be delivered by cesarean section. Left scapula-anterior (LSA) Right scapula-anterior (RSA) Left scapula-posterior (LSP)
The primitive streak is a structure that forms in the early embryo in amniotes. [1] In amphibians, the equivalent structure is the blastopore. [2] During early embryonic development, the embryonic disc becomes oval shaped, and then pear-shaped with the broad end towards the anterior, and the narrower region projected to the posterior.
Limb development in vertebrates is an area of active research in both developmental and evolutionary biology, with much of the latter work focused on the transition from fin to limb. [ 1 ] Limb formation begins in the morphogenetic limb field , as mesenchymal cells from the lateral plate mesoderm proliferate to the point that they cause the ...
The anterior/posterior axis is specified by the sperm at the posterior side. At the two cell stage, the anterior cell is the AB cell while the posterior cell is the P1 cell. The dorsal/ventral axis of the animal is set by a random position of cells during the four cell stage of the embryo.
The anterior end of the egg becomes the head; posterior end becomes the tail. the dorsal side is on the top; the ventral side is in underneath. The products of maternal effect genes called maternal mRNAs are produced by nurse cell and follicle cells and deposited in the egg cells (oocytes).
1 - morula, 2 - blastula 1 - blastula, 2 - gastrula with blastopore; orange - ectoderm, red - endoderm. Embryology (from Greek ἔμβρυον, embryon, "the unborn, embryo"; and -λογία, -logia) is the branch of animal biology that studies the prenatal development of gametes (sex cells), fertilization, and development of embryos and fetuses.