Babies Essays

Babies Essays Babies Essay Babies Essay How is the baby’s due date calculated and why is it often hard to calculate? The baby’s due date is calculated by doctors and midwives from the beginning of the mother’s last period. This marker is used because it is difficult to determine exactly when the mother is ovulating and as a result when the sperm is fertilized the egg. 2) Briefly explain the process of conception? Ovulation, Development of Corpus Luteum, Release of Egg, Menses, Fertilization, Implantation, Pregnancy Hormones. 3) What is DNA? DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms.Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus but a small amount of DNA can also be found in the mitochondria. 4) How long is the germinal stage? Explain what happens in this stage. The germinal stage lasts only about 2 weeks. Within just a few hours after conception, the single-celled zygote begins making a journ ey down the fallopian tube to the uterus where it will begin the process of cell division and growth. 5) How can pregnancy be detected? What hormones play a significant role in this? You can detect pregnancy by certain symptoms. A pregnancy test can be detected.The hCG hormone plays a role in this. 6) Describe the physical development that occurs in relation to the ectoderm, mesoderm and endoderm. 7) What happens 18 days after conception? The embryo commences growth inside the uterus. It is divided into three layers that will later form organs and tissues. The neural tube develops in the top layer. Some of these cells will further specialise, sprouting outward to cover the body with skin, hair and nails. The heart and the circulatory system begin to appear in the middle layer. The third layer starts to house the lungs, intestines and beginnings of the urinary system.In the meantime, the early division of the placenta, the chorionic villi, and the umbilical cord, which delivers nouri shment and oxygen to the embryo, are already working. Low on the sides of the head, two folds are evident – tissue that will become the ears. 8) Why is the embryonic stage considered a critical period? Because the embryonic period is the time when the embryo grows up in to fetus by performing several processes, these process are so much important that if these are not happen in the mean time then the fetus may catch many deformities and anomolies . ) Briefly describe the foetal stage. The fetal stage of prenatal development may be defined as beginning at the 11th week in gestational age, which is the 9th week after fertilization. In biological terms, however, prenatal development is a continuum, with no clear defining feature distinguishing an embryo from a fetus. The use of the term fetus generally implies that a mammalian embryo has developed to the point of being recognizable as belonging to its own species, though the point at which this occurs is subjective.A fetus is al so characterized by the presence of all the major body organs, though they may not yet be fully functional, or situated in their final anatomical location. 10) What is the placenta? Discuss its importance. The placenta is an organ attached to the lining of your womb during pregnancy. It keeps your unborn baby’s blood supply separate from your own blood supply, as well as providing a link between the two. The link enables the placenta to carry out functions that your unborn baby can’t perform for itself. The placenta is linked to your baby by the umbilical cord.Your baby is inside a bag of fluid called the amniotic sac, which is made of membranes. Oxygen and food pass from your blood supply into the placenta. From there, the umbilical cord carries the oxygen and food to your unborn baby. Waste products from the baby, such as carbon dioxide, pass back along the umbilical cord to the placenta and then into your bloodstream, for your body to dispose of them. The placenta p roduces hormones that help your baby to grow and develop. The placenta also gives some protection against infection for your baby while its in the womb. It protects your baby against most bacteria.However, it does not protect your baby against viruses. For example, if you’re not immune to the rubella virus (German measles), it can cross the placenta and cause miscarriage, stillbirth or birth defects such as deafness, brain damage, heart defects and cataracts. Alcohol, nicotine and other drugs can also cross the placenta and can cause damage to your unborn baby. Towards the end of your pregnancy, the placenta passes antibodies from you to your baby, giving them immunity for about three months after birth. However, it only passes on antibodies that you already have.