Pregnancy is the result of the joining of a sperm and an egg cell during the process of fertilization. The more precise phrase "natural" or "in vivo" fertilization refers to this internal process of human fertilization, which means that it occurs inside the body of the woman, notably in the Fallopian tube.
The binding of the egg and sperm can also be done in a laboratory. The use of assisted reproductive technology (ART) or In Vitro Fertilization (IVF) is recommended for couples facing difficulties in conception due to various reasons.
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What is Fertilization?
The fusing of the male and female gametes, or sperm and egg, is known as fertilization. This process brings together an equal number of chromosomes from the male and female, such that the fetus then has 46 chromosomes, which is normal for humans.
Male semen contains millions of sperms. When the semen enters the woman's vagina, these sperms swim upwards through the cervix towards to fallopian tubes, where the egg cell is situated. It takes only one sperm to penetrate through the outer layer of the egg cell or ovum for fertilization to take place.
However, the sperm cannot survive for long in the woman’s body. This is why it is useful to keep track of your ovulation so that the egg cell is present when the sperm enters the body. Once you are pregnant, book an appointment with the best pediatrician in Hyderabad, who can guide you about everything there is to know about a newborn baby and how to take care of her.
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Process of Fertilization
Step 1: Capacitation of Sperm: The process of the getting sperm ready for fertilization is known as "sperm capping." The sperm gets more mobile as it grows hyperactive. This stage makes sure the sperm penetrates the egg cell.
Step 2: Sperm-Zona Pellucida Binding: In this stage, the sperm binds to the zona pellucida layer of the ovum to create a receptor-ligand response. Once this coupling event has taken place, no additional sperm can pass through this layer.
Step 3: Zona Pellucida Penetration: The sperm's head is designed in such a manner that it aids in penetrating the ovum's wall. Additionally, it promotes ovum development, which is paused during one meiotic stage. Immediately following fertilization, the next phases begin.
Step 4: Acrosome Reaction: A number of Zona Pellucida-digesting enzymes are carried by the sperm head, or acrosome, which helps the sperm penetrate further into the ovum’s layers. The head of the sperm contracts as it enters deeper into the ovum.
Step 5: Cortisol Reaction: The egg is now activated after being frozen throughout the meiotic division’s metaphase stage. Exocytosis is produced when the Zona Pellucida and cortical granules combine.
Step 6: Zona Reaction: This is the end of fertilization because the Pellucida Zona layer hardens.
Fun Facts About the Reproductive System
- The scrotum, which houses the testicles, is present outside the body because the process of sperm generation (spermatogenesis) requires an ideal temperature of 2 to 3oC lower than the usual human body temperature.
- Normally measuring 3 inches in length and 2 inches in width, a woman's uterus can enlarge up to 20 times while she is pregnant. One of the strongest muscles in a woman's body is found in the uterus.
If you have any more questions regarding the process of fertilization or pregnancy, visit a gynecologist, who will help and support you through the entire process.
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