(MAPC) LIFE SPAN PSYCHOLOGY (MPC-002) ANSWER 2017

QUESTION2-Define prenatal period. What are the environmental influences affecting the development of an infant.

ANS-Prenatal development is the process that occurs during the 40 weeks prior to the birth of a child. During each prenatal stage, environmental factors affect the development of the fetus. The developing fetus is completely dependent on the mother for life, and it is important that the mother receives prenatal care, which is medical care during pregnancy that monitors the health of both the mother and the fetus. According to the National Institutes of Health ([NIH], 2013), routine prenatal care can reduce the risk of complications to the mother and fetus during pregnancy.

When the zygote attaches to the wall of the uterus, the placenta is formed. The placenta provides nourishment and oxygen to the fetus. Most everything the mother ingests, including food, liquid, and even medication, travels through the placenta to the fetus—hence the common phrase that a mother "eats for two." Anything the mother is exposed to in the environment affects the fetus; if the mother is exposed to something harmful, the child can show life-long effects.

Prenatal development is typically divided into three distinct periods (zygote, embryo, fetus). In reality, these periods represent continuous phases of development, during which the organism, protected and sustained by the amniotic sac, the placenta, the umbilical cord, and after the fifth month, the lanugo, undergoes a systematic series of sequential changes to become increasingly complex and differentiated.

The Zygote

The period of the zygote, which lasts about two weeks, extends from fertilization to implantation, when the zygote becomes implanted in the wall of the uterus.

The Embryo

The period of the embryo begins at that point and lasts until the eighth week. During this period of rapid growth, most of the important organs and physiological systems develop, and the embryo is quite vulnerable to adverse environmental influences.

The Fetus

The period of the fetus extends from the beginning of the third month until birth. Although the major organ systems are well differentiated by this time, the central nervous system continues to develop at a rapid pace, reflexes develop, and regulatory processes and the respiratory system continue to mature. A danger at this time is respiratory distress syndrome; and if the child is born before the age of viability, or at 28 weeks, it may not be developed enough to survive.