A description of human fertilization

Persaud, The Developing Human: Association of a mammalian spermatozoon with the egg surface occurs along the lateral surface of the spermatozoon, rather than at the tip as in other animals, so that the spermatozoon lies flat on the egg surface.

Following ovulation, the fimbriated, or finger-like, end of the fallopian tube sweeps over the ovary. Wiley-Liss, ] In fact, many state laws already falsely define "conception" as "implantation.

Conception: How It Works

One procedure involves inserting the needle through the vagina transvaginally. Purpose IVF is one of several assisted reproductive techniques ART used to help infertile couples to conceive a child. Contact between the egg and sperm A description of human fertilization random. Human development begins at fertilization, the process during which a male gamete or sperm Sperm Transport The transport of sperm is dependent upon several factors: The "abortion pill" RU also destroys the conceptus by interrupting implantation because of interference with the hormonal environment of the implanting embryo.

The added stress and expense of multiple clinic visits, testing, treatments, and surgical procedures can become overwhelming.

Human fertilization

IVF is one of several possible methods to increase the chance for an infertile couple to become pregnant. The zygote thus produced is then introduced into the uterus and allowed to develop to term.

There is a slight risk of ovarian rupture, bleeding, infections, and complications of anesthesia. That single-cell embryo is totipotent, i. Ovarian hormones estrogen taken in large doses within 72 hours after sexual intercourse usually prevent implantation of the blastocyst, probably by altering tubal motility, interfering with corpus luteum function, or causing abnormal changes in the endometrium.

Although fertilization may occur in other parts of the tube, it does not occur in the uterus. In fact, there is a range of both totipotent and pluripotent cells in the early developing human embryo. At the point on the outer surface of the sea urchin egg at which a spermatozoan attaches, the thin vitelline membrane becomes detached.

The cilia within the tube, and muscular contractions resulting from the movement of the egg, create a forward motion. Biochemical analysis of fertilization Many of the early studies on biochemical changes occurring during fertilization were concerned with the respiratory metabolism of the egg.

The woman may be given a sedative prior to the procedure.

in vitro fertilization

Want to thank TFD for its existence? In normal sexual reproduction between a man and a woman, where fertilization takes place in your fallopian tube not in your uterusyou are already pregnant when the day embryo implants. Human development begins when an oocyte is fertilized.

The procedure takes from 2 to 3 days. In fact, whole spermatozoa injected into unfertilized eggs cannot elicit the activation reaction or merge with the egg nucleus. If twinning is cloning which it isand if it is used to asexually reproduce new embryos for implanting into women as infertility treatments, then at least this form of reproductive cloning has been going on for decades now.

Thus, they are genetically identical. The fertilized eggs can then be returned to the uterus, as in IVF. If "regulation" fails, then the embryo or the cells die.

Human pregnancy begins with the fusion of an egg and a sperm.The footage gives a visual description of the process of fertilisation.


Following the journey of both sperm and egg, CGI graphics provide a brilliant insight into the topic and includes research along with the key facts and processeses that students need to know. Fertilization: Fertilization, Despite the many early descriptions of spermatozoa, their essential role in fertilization was not proved untilwhen the Swiss physician and zoologist Hermann Fol observed the penetration of a spermatozoon into an ovum.

Human Reproduction Questions - All Grades

human genetics: Fertilization, sex determination, and differentiation. A human. When does conception, or fertilization, occur?

An egg matures in a female's ovary. All 23 pairs of chromosomes are present. A dominant gene overrides a recessive gene. Sperm from a male unites with an egg from a female.

Fertilization — sperm union with the egg — occurs in this portion of the tube. The fertilized egg then begins a rapid descent to the uterus. The period of rest in the tube appears to be necessary for full development of the fertilized egg and for the uterus to prepare to receive the egg.

Fertilization is the first step that needs to happen to make a baby! In simple terms, fertilization occurs when the sperm and egg combine to create an embryo. In order for a man and woman to make a baby, you need a brain, a uterus, fallopian tubes, sperm and healthy eggs.

Once a woman is determined to be a good candidate for in vitro fertilization, she will generally be given "fertility drugs" to stimulate ovulation and the development of multiple eggs. These drugs may include gonadotropin releasing hormone agonists (GnRHa), Pergonal, Clomid, or .

A description of human fertilization
Rated 0/5 based on 33 review