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Immediately after meiosis I, the haploid secondary oocyte initiates meiosis II. However, this process is also halted at the metaphase II stage until fertilization , if such should ever occur. If the egg is not fertilized, it is disintegrated and released ( menstruation ) and the secondary oocyte does not complete meiosis II (and does not become ...
Oocyte (or ovum/egg) activation is a series of processes that occur in the oocyte during fertilization.. Sperm entry causes calcium release into the oocyte. In mammals, this is caused by the introduction of phospholipase C isoform zeta (PLCζ) from the sperm cytoplasm. [1]
After birth, the fundus contracts downward into the pelvis one centimeter each day. After two weeks the uterus will have contracted and return into the pelvis. [ 9 ] The sensation and strength of postpartum uterine contractions can be stronger in women who have previously delivered a child or children.
After about a week, a fully functional synapse is formed following several types of differentiation in both the post-synaptic muscle cell and the pre-synaptic motor neuron. This pioneer axon is of crucial importance because the new axons that follow have a high propensity for forming contacts with well-established synapses.
Development before birth, or prenatal development (from Latin natalis ' relating to birth ') is the process in which a zygote, and later an embryo, and then a fetus develops during gestation. Prenatal development starts with fertilization and the formation of the zygote , the first stage in embryonic development which continues in fetal ...
Nine-week-old human embryo from an ectopic pregnancy. Organogenesis is the development of the organs that begins during the third to eighth week, and continues until birth. Sometimes full development, as in the lungs, continues after birth. Different organs take part in the development of the many organ systems of the body.
Ovarian follicle activation can be defined as primordial follicles in the ovary moving from a quiescent (inactive) to a growing phase. The primordial follicle in the ovary is what makes up the “pool” of follicles that will be induced to enter growth and developmental changes that change them into pre-ovulatory follicles, ready to be released during ovulation.
During pregnancy the plasma volume increases by 40-50% and the red blood cell volume increases only by 20–30%. [22] These changes occur mostly in the second trimester and prior to 32 weeks gestation. [24] Due to dilution, the net result is a decrease in hematocrit or hemoglobin, which are measures of red blood cell concentration.