Psyc Module 3

Study Notes

Prenatal Development Overview

Prenatal development is the transformation of a zygote into a newborn, divided into three major periods: Germinal, Embryonic, and Fetal stages.

Germinal Stage

Begins with conception on Day 1, where sperm and ovum unite to form a zygote, containing unique genetic instructions.
Implantation occurs between days 10-14, as the zygote embeds into the uterine lining.
Specialized cells differentiate to form the placenta, umbilical cord, and embryo during this stage.

Embryonic Stage

Lasts from weeks 3 to 8, characterized by organogenesis, where all organ systems develop within this six-week timeframe.
This period follows implantation and is critical for initial body structure formation.

Fetal Stage

Spanning weeks 9 to 38, marked by significant growth and refinement of organs.
The fetus increases from 2.5 cm and 7 g to approximately 51 cm and 3.2 kg by birth.
By week 12, sex differentiation allows identification of male or female fetuses.
Viability is achievable by week 24 due to changes in brain and lung development.

Developmental Patterns

Cephalocaudal pattern indicates growth from the head downward.
Proximodistal pattern describes growth starting from the center of the body outward.

Gonads and Gender Development

Gonads develop into testes in males and ovaries in females.
Androgens promote the development of male genitalia, while their absence leads to female development.
Structural brain differences between sexes may influence cognitive skills, such as spatial and verbal abilities, aggression, communication, and potentially sexual orientation.

Fetal Learning and Prenatal Environment

Fetuses can recognize familiar sounds from their environment inside the womb, highlighting early learning capabilities.

Teratogens and Their Effects

Teratogens are agents or conditions that lead to congenital anomalies in fetal development.
Drugs can lead to lower birth weight, fetal death, and neurobehavioral disorders.
Alcohol exposure can cause Fetal Alcohol Syndrome (FAS).
Maternal diseases can result in fetal death or impairments like loss of vision or hearing.
Nutrition is crucial; inadequate nutrients are related to neural tube defects and malnutrition can increase risks of low birth weight and mental illnesses in adulthood.

Challenges in Teratogen Research

Assessing precise teratogenic effects is complicated by variables such as genetics and environmental influences, particularly during sensitive development periods.

Neonatal Behavioral Assessments

The Apgar Scale evaluates newborns' immediate need for assistance with breathing.
The Brazelton Neonatal Behavioral Assessment Scale monitors a newborn's development in the initial weeks after birth.
Assessment scores help identify potential neurological problems, facilitating early medical intervention to address physical or neurological issues.

Description

Explore the fascinating stages of prenatal development, from conception through the embryonic stage. This quiz covers the germinal stage and its key events, leading to the formation of critical structures such as the placenta and umbilical cord. Test your knowledge on the processes that turn a zygote into a newborn during these vital early periods.