The scientific viewpoint on the issue. Many people try to claim that the unborn is just a blob of tissue, nothing more than a tumor. But it is a scientific and medical fact, based on experimental evidence, that the fetus is a living, growing, thriving human being, directing his or her own development. The unborn baby is never part of the mother's body. By the end of the second week of pregnancy, there is a distinct embryo present. The fetus has a developing brain and a rudimentary heart. By the end of the third week of pregnancy, the fetus has the beginnings of vetrebrae, developing eyes and ears, a closed circulatory system (separate from the mother's), a working heart, the beginnings of lungs, and budding limbs. By the end of the fourth week of pregnancy, the fetus has a developing nose, and a pancreas. By the end of the fifth week of pregnancy, the fetus has the beginnings of vertebrae, a bony jaw and clavicle, developing eyes, ears, and nose, a closed circulatory system, a working heart, lungs, limbs, hands, feet, and a pancreas. By the end of the sixth week of pregnancy, the fetus has a vertebral column, a bony jaw and clavicle, a primative cranium, ribs, a developing nervous system, a closed circulatory system with a working heart, developing eyes, ears, and nose, lungs, lim bs, hands, feet, a pancreas, a bladder, kidneys, a tongue, a larynx, a thyroid body, and germs of teeth. By the end of the seventh week of pregnancy, the fetus has a vertebral column, a bony jaw and clavicle, a primitive cranium, ribs, femur, tibia, palate, upper jaw, developing nervous system, a closed circulatory system with a working heart, developing eyes,ears, and nose, lungs, arms, legs, hands, feet, a pancreas, a bladder, kidneys, a tongue, a larynx, a thyroid body, germs of teeth, and the beginnings of muscles. By the end of the second month of pregnancy, the fetus has a vertebral column, a bony jaw, clavicle, and palate, a cranium, ribcage, femur, tibia, forearms that can be distinguished from arms, and thighs that can be distinguished from legs, a developi ng nervous sytem, sympathetic nerves (meaning the fetus can feel pain), a closed circulatory system and a working heart, eyes, developing ears and nose, lungs, arms and forearms, legs and thighs, hands and feet, a pancreas, a bladder, kidneys, a tongue, a larynx, a thyroid, germs of teeth, and developing muscles. --gray's anatomy
