Human Reproduction
How do humans reproduce
Female reproduction organs and their function
Vagina: The vagina is a canal that joins the cervix (the lower part of uterus) to the outside of the body. It also is known as the birth canal.
Uterus (womb): The uterus is a hollow, pear-shaped organ that is the home to a developing fetus. The uterus is divided into two parts: the cervix, which is the lower part that opens into the vagina, and the main body of the uterus, called the corpus. The corpus can easily expand to hold a developing baby. A channel through the cervix allows sperm to enter and menstrual blood to exit.
Ovaries: The ovaries are small, oval-shaped glands that are located on either side of the uterus. The ovaries produce eggs and hormones.
Fallopian tubes: These are narrow tubes that are attached to the upper part of the uterus and serve as tunnels for the ova (egg cells) to travel from the ovaries to the uterus. Conception, the fertilization of an egg by a sperm, normally occurs in the fallopian tubes. The fertilized egg then moves to the uterus, where it implants into the lining of the uterine wall.
Male reproductive organs and their function
Penis: This is the male organ used in sexual intercourse. It has three parts: the root, which attaches to the wall of the abdomen; the body, or shaft; and the glans, which is the cone-shaped part at the end of the penis. The glans, also called the head of the penis, is covered with a loose layer of skin called foreskin. This skin is sometimes removed in a procedure called circumsission The opening of the urethra, the tube that transports semen and urine, is at the tip of the penis. The penis also contains a number of sensitive nerve endings.
Testicles (testes): These are oval organs about the size of large olives that lie in the scrotum, secured at either end by a structure called the spermatic cord. Most men have two testes. The testes are responsible for making testosterone, the primary male sex hormone, and for generating sperm. Within the testes are coiled masses of tubes called seminiferous tubules. These tubes are responsible for producing sperm cells.
Prostate gland: The prostate gland is a walnut-sized structure that is located below the urinary bladder in front of the rectum. The prostate gland contributes additional fluid to the ejaculate. Prostate fluids also help to nourish the sperm. The urethra, which carries the ejaculate to be expelled during orgasm, runs through the center of the prostate gland.
Urethra: The urethra is the tube that carries urine from the bladder to outside of the body. In males, it has the additional function of ejaculating semen when the man reaches orgasm. When the penis is erect during sex, the flow of urine is blocked from the urethra, allowing only semen to be ejaculated at orgasm.
Puberty
Puberty is the process of physical changes by which a child's body matures into an adult body capable of sexual reproduction to enable fertilisation. It is initiated by hormaonal signals from the brain to the gonads; the ovaries on a girl, the testes in a boy. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscles,blood, skin, hair, breasts and sexual organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when the child has developed an adult body. Until the maturation of their reproductive capabilities, the pre-pubertal, physical differences between boys and girls are the genitalia, the penis and the vagina
Fertilisation of the female egg by male sperm
In addition to all the fun, your bodies are building up tension that you hope will end in orgasm. Having an orgasm also has an important biological function. In men, orgasm propels sperm-rich semen into the vagina and up towards the cervix at roughly 10 miles per hour. The force of ejaculation gives the sperm a good head start on their way to the egg. A woman doesn't need to orgasm for conception to happen. Gentle uterine contractions can help the sperm along, but these happen without you having an orgasm
Growth of baby in mother
During fertilisation, the genetic material in the sperm and egg combine to create a new cell that will rapidly start dividing. This bundle of new cells is known as the blastocyst. It continues travelling down the fallopian tube towards the uterus, a journey which can take another three days or so.
You are not actually pregnant until the blastocyst has attached itself to the wall of your uterus, where it will develop into an embryo and placenta. Occasionally, the blastocyst will implant somewhere other than the uterus (usually in the fallopian tube). This is called an ectopic pregnacy, which is a medical emergency. The pregnancy will not survive outside the uterus and needs to be completely removed, to avoid damage to the fallopian tube.
It will be a couple of weeks until you miss a period and suspect that you're going to have a baby. Once you have missed your period or noticed one of the othersigns of pregnacy, a home pregnacy test will confirm it. If you've got a little one on the way,
Birth
Birth is the act or process of bearing or bringing forth offspring from the uterus. The offspring is brought forth from the mother. The time of human birth is defined as the time at which the fetus comes out of the mother's womb into the world
Words I need to Define
Foetus:A fetus, also spelled foetus, fœtus, faetus, or fætus, is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.
Embryo:An organism in its early stages of development, especially before it has reached a distinctively recognizable form.
Gametes: A reproductive cell having the haploid number of chromosomes, especially a mature sperm or egg capable of fusing with a gamete of the opposite sex to produce the fertilized egg.
Gestation: The period of development in the uterus from conception until birth; pregnancy