This paper examines the biological processes of human reproduction, beginning with contraception and the roles of male and female gametes in fertilization. It traces fetal development through all three trimesters of pregnancy, detailing key milestones from embryonic formation through organ development. The paper concludes with an explanation of labor, delivery, and the immediate postnatal period. The work provides a detailed chronology of pregnancy development, emphasizing hormonal changes, structural formation, and physiological preparation for birth.
Contraception begins when a male and female have sexual intercourse and ejaculation from the male is released into the female genitals at the end of intercourse. It takes two to three months to create a new sperm cell. The ejaculation releases the male gamete cell known as the sperm cell; at least 40 million of these cells are released with one ejaculation, so men must make these sperm cells through most of their adult life. This production starts in the testes and they are stored there as well, maintained at a perfect temperature of 34 degrees Celsius. Though 40 million sperm are sent into the woman's uterus, only one male gamete cell can fertilize an egg. Their purpose is to reach the female gamete cell and to fertilize it as quickly as possible.
The female gamete cell, known as the egg cell, is made in the ovaries, which are two ovals attached to the fallopian tubes. Every woman is born with one to two million egg cells in their ovaries, though they decrease in number as you grow older. During each menstrual cycle, an egg cell ripens and is released into the fallopian tube, which is about 10 centimeters in length. This tube leads the egg from the ovaries to the uterus. The egg lives for about 24 hours after it has been released and needs to be fertilized within this time to conceive a baby.
If a sperm meets an egg, fertilization takes place and the fertilized egg is now known as an embryo. The genetic makeup of each gamete cell combines and starts to create a baby. The cell that is fertilized starts to divide, and this cell is then called a blastocyst, which normally occurs within 5 days of fertilization. This blastocyst will travel down to the uterus, where it then attaches itself to the uterus wall. Here it will develop into an embryo and placenta. This part of the pregnancy is called implantation.
The blastocyst starts to produce the human chorionic gonadotropin hormone into your bloodstream, which tells the lining of the uterus to stay in place and not disintegrate as it usually would. The period between conception and birth is known as the gestation period, which lasts for 40 weeks. There are 3 trimesters in pregnancy.
After implantation and hormonal changes, the woman would be around 5 weeks pregnant, which is when the embryonic stage begins. At this stage the embryo has grown to 2 millimeters and is starting to produce amniotic fluid. The placenta is starting to develop, and by the end of the fifth week the embryo will have nearly doubled in size to about 4–5 millimeters. Nerves begin to grow as a group of cells on the back of the embryo fold over to form a tube, which will grow into a spinal cord.
In week 6, the first blood cells are developing and a pipe-shaped heart has formed and is beginning to beat. The embryo has reached 8 millimeters. In week 8 (6 weeks from conception), the embryo measures around 18 millimeters and arms and legs are now growing. The face is beginning to take shape. In week 10, the embryo is now a fetus, and the body muscles are almost fully developed.
In week 14, the eyes have moved from the sides of the head to the front and eyelashes have now formed. A very fine covering called lanugo has formed over the fetus. In week 16, the bones are hardening and nails are developing. In week 19, the buds of teeth start forming.
When week 20 arrives, vernix appears on the baby's skin, which is a waxy white substance that coats the skin of newborn babies and protects the baby before birth from the amniotic fluid. In week 23, the baby's fingerprints are formed.
Week 27 marks the beginning of the third trimester. In week 29, the lungs are maturing in preparation for the first breath. In week 34, the body's organs are more developed and the kidney is passing fluid through, which is recycled back to the amniotic sac. In week 35, the baby has rapid weight gain and is getting ready for birth.
"Childbirth process and immediate newborn care"
You’re 77% through this paper. Sign up to read the remaining 1 section.
Sign Up Now — Instant Access Already a member? Log inAlways verify citation format against your institution’s current style guide requirements.