A new human being usually begins the first day of his life as a single-cell human embryo at the beginning of the biological process that continues throughout a human being’s life. At that moment, a new human person, who carries with him as much information as 50 sets of the Encyclopedia Britannica, is formed. This genetic information – DNA – will determine all of this little person’s physical characteristics and much of his intelligence and personality.
Our little friend is now three cells big. His cells will continue to divide as he starts down his mother’s Fallopian tube toward her uterus (womb), where he will get the food and shelter he needs to grow and develop.
Implantation into his mother’s uterus begins and all the while he continues to grow. As his cells multiply, they differentiate to perform specific functions – circulatory, muscular, neural and skeletal.
Implantation is completed around this time and his mother misses her first menstrual period.
His hear, brain, spinal column, and nervous system are almost complete and his eyes begin to form.
His heart begins to beat.
His muscles are developing, and arms and leg buds are visible. His large, distinct head is clearly identifiable, along with the major outlines of brain and eye vesicles, the beginnings of his central nervous system, notochord, mouth and pharynx, body cavity, and the basis of his skeleton.
Our little friend’s face is taking shape; his forehead, eyes, nostrils and mouth are evident; external ears are beginning; hand and foot plates appear in his limb buds.
The brainwaves of this little boy can be recorded. His different muscles begin working together.
His fingers and toes are fairly well defined, and fingerprints, a unique and defining feature of every human being, are permanently engraved on his skin. All of his organs are present, complete, and functioning (except his lungs).
All areas of his body are sensitive to touch. He sucks his thumbs, swallows, squints, frowns and puckers his brow. If his palm is stroked, he will make a tight fist.
He now has fingernails, toenails and working taste buds. He can also make all facial expressions, including a smile.
Although this baby was already a boy at fertilization, his sex is now identifiable.
This little baby’s heart is pumping six gallons of blood every day, and his mom can now feel him jumping around and turning somersaults, exercising the muscles and lungs he will need to live outside his mother’s womb. Rapid eye movement (REM) can be recorded while he’s sleeping, indicating that he is dreaming.
He now weighs about one pound and is a foot long. If he is born now, he would have a 50 percent chance of surviving with the help of dedicated doctors and nurses.
He can open and close his eyes and recognizes his mom’s voice. His weight continues to increase and “baby fat” fills out and smoothers his skin. If he is born now, his chance of surviving increases to 90 percent.
When he is ready to be born, he will release hormones to trigger labor. He may weigh between 7 and 9 pounds, and can be between 18 and 21 inches long!