fertilization

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fertilization

 [fer″tĭ-lĭ-za´shun]
in human reproduction, the process by which the male's sperm unites with the female's oocyte, creating a new life. The sex and other biologic traits of the new individual are determined by the combined genes and chromosomes that exist in the sperm and oocyte. See also conception and reproduction. Called also fecundation and impregnation.

After injection into the vagina, millions of sperm cells (spermatozoa) make use of their whiplike tails to swim through the cervix toward the uterus. Most are destroyed along the way by secretions in the vagina, but some reach the uterus and a few may enter the fallopian tubes. A very small number may survive as long as 48 hours. If during this period only one sperm succeeds in entering a fallopian tube and meeting there an oocyte ready to be fertilized, conception can occur. This event is possible only during a period of about 4 days of the month. After the sperm lodges in the oocyte, the tail disappears, but the head unites with the oocyte to form the zygote.
in vitro fertilization the process by which conception takes place in a laboratory medium; the term literally means fertilization “in glass.” A lay term for the product of in vitro fertilization is “test tube baby.”

The treatment cycle involves the following steps: (1) Induction of ovulation with fertility drugs, such as clomiphene citrate, injectable follicle-stimulating hormone/luteinizing hormone, or both, to produce multiple ovarian follicles. When the largest follicle reaches 20 mm in diameter the patient is given an injection of human chorionic gonadotropin to induce expulsion of the oocyte from the follicle. (2) Laparoscopy and follicular aspiration for the harvesting of oocytes. (3) Maturation of retrieved oocytes and inoculation with the husband's or donor's sperm. (4) Incubation of the resulting embryos until they reach the two- to six-cell stage. (5) Transfer of an embryo via catheter into the patient's uterus; at this point intensive intervention ceases, the pregnancy is considered normal, and no further manipulation is required.
in vivo fertilization union of the sperm and ovum within the reproductive tract of the female; usually taken to mean artificial insemination in which the sperm is artificially introduced into the vagina, cervix, or uterine cavity to overcome the problem of infertility.

fer·til·i·za·tion

(fer'til-i-zā'shŭn),
The process beginning with penetration of the secondary oocyte by the sperm and completed by fusion of the male and female pronuclei.

fertilization

(fûr′tl-ĭ-zā′shən)
n.
1. The act or process of initiating biological reproduction by insemination or pollination.
2. The union of male and female gametes to form a zygote.
3. The act or process of applying a fertilizer.

fer′til·i·za′tion·al adj.

fertilization

Fusion of ovum & spermatozoon Reproduction medicine The penetration of an egg by sperm, resulting in combined genetic material that develops into an embryo

fer·til·i·za·tion

(fĕr'til-ī-zā'shŭn)
The process beginning with penetration of the secondary oocyte by the sperm and completed by fusion of the male and female pronuclei.

fertilization

(fert?il-i-za'shon) [L. fertilis, reproductive]
Enlarge picture
FERTILIZATION
The process that begins with the penetration of the secondary oocyte by the spermatozoon and is completed with the fusion of the male and female pronuclei. This usually takes place in the fallopian tube. Viable spermatozoa have been found in the tube 48 hr after the last coitus. After the ovum is fertilized and the diploid chromosome number is restored in the zygote, cell division begins. The blastocyst then enters the uterus, where it may implant for continued nurture and development. See: illustration

heterologous fertilization

Assisted fertilization of a woman's ova with donor sperm.
See: in vitro fertilization; artificial insemination

homologous fertilization

Artificial fertilization of a woman's ovum by her husband's sperm. The ovum and sperm are united while both are outside the body and then are placed in the uterus during the optimum time for fertilization.

in vitro fertilization

Abbreviation: IVF
Laboratory-produced conception, used to enable pregnancy in infertile women when sperm access to ova is prevented by structural defects in the fallopian tubes or other factors, or in combination with her partner's sterility. After drug-induced follicle maturation, a sample of ova and follicular fluid is removed surgically and mixed with a specimen of the partner's sperm for incubation. The resulting zygote is introduced into the woman's uterus for implantation.
See: embryo transfer; GIFT; ZIFTillustration

fertilization

The union of the spermatozoon with the egg (ovum) so that the full complement of chromosomes is made up and the process of cell division, to form a new individual, started.

fertilization

the fusion of male and female GAMETES to give rise to a ZYGOTE which then subsequently develops into a new organism. See ACROSOME for further details of animal fertilization. See EMBRYO SAC for details of the ‘double’ fertilization of flowering plants.

Fertilization

The joining of the sperm and the egg; conception.
Mentioned in: Contraception

fer·til·i·za·tion

(fĕr'til-ī-zā'shŭn)
Process beginning with penetration of secondary oocyte by one or more sperm(s) and completed by fusion of the male and female pronuclei.

Patient discussion about fertilization

Q. i just have my period last november 25 and ended on 28.when is my possible fertile and ovulation period please help me identify my fertile and ovulation period

A. If someone knew it, it'd solve the human race many problems with fertility. The problem is that ovulation (and thus, the period of possible fertility) happens 14 days BEFORE the onset of menses, so you know about it only retrospectively.

However there ways such as serial body temperature measuring, along with kits that measures the level of hormones in the urine in order to estimate the time of the coming ovulation, and help in timing intercourse.

You may read more about it here (www.mayoclinic.com/health/ovulation-signs/AN01521 ) but anyway, consulting a doctor (e.g. gynecologist) may be wise.

More discussions about fertilization
References in periodicals archive ?
Paternity analyses need to be conducted on early embryos to positively discriminate between fertilization and embryo viability effects (e.g., Huvet et al., 2001).
Assemble a list of the ways iron fertilization might harm the ocean--as the Scientific Group of the London Convention did earlier this year--and it quickly becomes lengthy and distressing.
Whereas, assortative fertilization or gamete preference, which is commonly regarded as a post-mating, pre-zygotic isolating mechanism, has only recently come to prominence and is increasingly accepted as another important possible barrier to hybridization and gene flow between closely related species (Bierne et al.
One of the few researchers to specifically investigate the effect of low salinity on both fertilization and cleavage was the remarkable E.
Significant yield responses to N fertilization have been reported, as well as possible residual effects of repeated N applications on triticale cycles (Marton, 2002).
Thus, the aim of this research was to understand the effects of coverage with nitrogen and macro and micronutrients leaf fertilization on yield and physiological quality of upland rice seeds.
The study objectives were to (i) evaluate the effectiveness of N, P, and K fertilization on yield, oil andprotein contents of winter rapeseed and (ii) explore the responses of rapeseed quality to N, P, and K application on five major fatty acids.
Fresh and dry matter productions at 620 DAP were dependent on the interactions (p < 0.05) between the planting spacings and fertilizations (Table 3).
He said that they found that the egg itself plays no significant role in promoting fertilization precedence by their own species' sperm and instead it is actually the ovarian fluid that controls which species' sperm wins the fertilizations, which was unexpected.
(2007), increases in average weight of the pineapple fruit can be obtained when plants are subjected to a proper mineral fertilization.
But economists conclude that the growing urgency to solve our emissions problem will reward anyone who can make iron fertilization work.
While the previous analysis tests for contamination bias between the two alleles possessed by focal males, data from the competitor-free trials permit an explicit assessment of how many fertilizations were obtained by males from outside of the experimental arrays.