Search results
Results From The WOW.Com Content Network
Human growthand development. Human fertilization is the union of an egg and sperm, occurring primarily in the ampulla of the fallopian tube. [1] The result of this union leads to the production of a fertilized egg called a zygote, initiating embryonic development. Scientists discovered the dynamics of human fertilization in the 19th century.
Pregnancy is divided into three trimesters of approximately three months each. The first trimester includes conception, which is when the sperm fertilizes the egg. The fertilized egg then travels down the fallopian tube and attaches to the inside of the uterus, where it begins to form the embryo and placenta. During the first trimester, the ...
Human embryonic development or human embryogenesis is the development and formation of the human embryo. It is characterised by the processes of cell division and cellular differentiation of the embryo that occurs during the early stages of development. In biological terms, the development of the human body entails growth from a one-celled ...
Ovulation marks the end of the follicular phase of the ovarian cycle, and the start of the luteal phase. Ovulation is the release of egg cells from the ovaries as part of the ovarian cycle for most vertebrates. In women, this event occurs at the end of the follicular phase, when the ovarian follicles rupture and release the secondary oocyte ...
Human reproduction is sexual reproduction that results in human fertilization to produce a human offspring. It typically involves sexual intercourse between a sexually mature human male and female. [1] During sexual intercourse, the interaction between the male and female reproductive systems results in fertilization of the ovum by the sperm to ...
After the pollen tube enters the gametophyte, the pollen tube nucleus disintegrates and the two sperm cells are released; one of the two sperm cells fertilises the egg cell (at the bottom of the gametophyte near the micropyle), forming a diploid (2n) zygote. This is the point when fertilisation actually occurs; pollination and fertilisation are ...
Menstrual cycle The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that makes pregnancy possible. The ovarian cycle controls the production and release of eggs and the cyclic release of estrogen and progesterone. The uterine cycle governs the preparation and maintenance of the lining of the ...
Of all women receiving fertility treatment, 78 percent received advice. Fertility drugs act like hormones, and for women are used to trigger ovulation or to stimulate the production of better or ...