What is the basic event in reproduction

Overview What are the three stages of fetal development called? Fetal development is an orderly and intricate process. It begins before you even know you’re There are three stages of fetal development: germinal, embryonic and fetal. Most people don’t talk about their pregnancy in these terms, but it can be helpful to know. Germinal stage The germinal stage is the shortest stage of fetal development. It begins at Embryonic stage The embryonic stage lasts from about the third week of pregnancy until the eighth week of pregnancy. The blastocyst begins to take on distinct human characteristics. It’s now called an embryo. Structures and organs like the neural tube (which later becomes the brain and spinal cord), head, eyes, mouth and limbs form. The embryo’s heart begins to develop and pulse around the sixth week. Buds that will become arms and legs also form around the sixth week. By the end of the eighth week, most of the embryo’s organs and systems take shape. For a lot of people, this is the point in pregnancy where Fetal stage The fetal stage of development begins around the ninth week and lasts until birth. This is when the embryo officially turns into a fetus. The fetus gets its assigned sex around nine weeks of pregnancy, although your healthcare provider can’t detect it on ultrasound yet. The fetus’s major organs and body systems continue to grow and mature. Things like fingernails, eyelashes and hair also grow. The fetus is able to move its limbs, although you may not...

Internal and external organs of the female reproductive system. What is the female reproductive system? The female reproductive system is the body parts that help women or people assigned female at birth (AFAB): • Have sexual intercourse. • Reproduce. • Menstruate. What are the parts of the female reproductive system? The female reproductive anatomy includes both external and internal parts. External parts The function of your external genitals are to protect the internal parts from infection and allow sperm to enter your vagina. Your vulva is the collective name for all your external genitals. A lot of people mistakenly use the term “vagina” to describe all female reproductive parts. However, your vagina is its own structure located inside your body. The main parts of your vulva or external genitals are: • Labia majora: Your labia majora (“large lips”) enclose and protect the other external reproductive organs. During puberty, hair growth occurs on the skin of the labia majora, which also contain sweat and oil-secreting glands. • Labia minora: Your labia minora (“small lips”) can have a variety of sizes and shapes. They lie just inside your labia majora, and surround the opening to your vagina (the canal that joins the lower part of your uterus to the outside of your body) and urethra (the tube that carries pee from your bladder to the outside of your body). This skin is very delicate and can become easily irritated and swollen. • Clitoris: Your two labia minora meet at y...

For this biological process to be carried out, certain organs and structures are required in both the male and the female. The source of the ova (the female germ cells) is the female At copulation, or This articles describes the organs, both male and female, that are involved in human reproduction. The reproductive process itself is covered in other articles. For a detailed discussion of the series of changes that occur in a woman’s body as her fetus develops, see see see see

How does conception occur? Conception (or fertilization) is when sperm and an egg join together. It’s one of the many steps that happen to create a Conception is closely related to a person’s Sperm production begins in the testicles of men or people assigned male at birth (AMAB). During ejaculation, millions of sperm cells are set free with the sole purpose of finding an egg to fertilize. When you have unprotected sex, sperm cells swim up through your vagina and into your fallopian tubes. Millions of sperm battle to reach and penetrate the egg, but only one breaks through the egg's outer layer to fertilize it. If sperm doesn't fertilize an egg, the egg dissolves. If a sperm is successful on its quest to fertilize an egg, the now fertilized egg (called a zygote) continues to move down your fallopian tube, dividing into two cells, then four cells, then more cells. About a week after the sperm has fertilized the egg, the zygote has traveled to your uterus. It's now a growing cluster of about 100 cells called a The blastocyst then attaches itself to the lining of your uterus (the endometrium). This attachment process is called implantation. However, just because conception occurs doesn't mean implantation will. Sometimes implantation doesn't happen, and you pass the fertilized egg in your next menstrual period. If implantation happens, the cells continue to divide — some cells Timeline of getting pregnant You calculate your menstrual cycle from the first day of menstrual bleed...

https://bio.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fbio.libretexts.org%2FBookshelves%2FIntroductory_and_General_Biology%2FBook%253A_General_Biology_(Boundless)%2F43%253A_Animal_Reproduction_and_Development%2F43.03%253A_Human_Reproductive_Anatomy_and_Gametogenesis%2F43.3C%253A__Gametogenesis_(Spermatogenesis_and_Oogenesis) Expand/collapse global hierarchy • Home • Bookshelves • Introductory and General Biology • Book: General Biology (Boundless) • 43: Animal Reproduction and Development • 43.3: Human Reproductive Anatomy and Gametogenesis • 43.3C: Gametogenesis (Spermatogenesis and Oogenesis) Expand/collapse global location \( \newcommand\) • • • • • • • Spermatogenesis and oogenesis are both forms of gametogenesis, in which a diploid gamete cell produces haploid sperm and egg cells, respectively. Key Points • Gametogenesis, the production of sperm (spermatogenesis) and eggs (oogenesis), takes place through the process of meiosis. • In oogenesis, diploid oogonium go through mitosis until one develops into a primary oocyte, which will begin the first meiotic division, but then arrest; it will finish this division as it develops in the follicle, giving rise to a haploid secondary oocyte and a smaller polar body. • The secondary oocyte begins the second meiotic division and then arrests again; it will not finish this division unless it is fertilized by a sperm; if this occurs, a mature ovum and another polar body is produced. • In spermatogenesis, diploid sperm...

In the reproductive process, a male sperm and a female egg provide the information required to produce another human being. Conception occurs when these cells join as the egg is fertilized. Pregnancy begins once the fertilized egg implants in the uterus. The embryo grows and becomes surrounded by structures that provide support and nourishment. Eyes, limbs, and organs appear as the embryo develops into a fetus. The fetus grows inside the uterus until pregnancy ends with labor and birth. By then all body systems are in place—including the reproductive system that can one day help produce another human being. 1. Fertilization: A Sperm and an Egg Form a Zygote During sexual intercourse, some sperm ejaculated from the male penis swim up through the female vagina and uterus toward an oocyte (egg cell) floating in one of the uterine tubes. The sperm and the egg are gametes. They each contain half the genetic information necessary for reproduction. When a sperm cell penetrates and fertilizes an egg, that genetic information combines. The 23 chromosomes from the sperm pair with 23 chromosomes in the egg, forming a 46-chromosome cell called a zygote. The zygote starts to divide and multiply. As it travels toward the uterus it divides to become a blastocyst, which will burrow into the uterine wall. 2. The Zygote Becomes an Embryo: Development Prior to and During Implantation A fertilized egg, or zygote, takes about five days to reach the uterus from the uterine tube. As it moves, th...