Exam 2 Developmental Psychology Notes
- Conception occurs when a single sperm cell from the male unites with an ovum (egg) in
a female’s fallopian tube in a process called fertilization.
occurs from two to eight weeks after conception. Creation
of the fertilized egg, cell division, attachment of the zygote to the uterine wall.
The group of cells now called the blastocyst consists of an inner mass of cells
that will eventually develop into the embryo and the trophoblast, an outer
layer of cells that later provides nutrition and support for the embryo.
Implantation (attachment of the zygote to the uterine wall, takes place about
10 to 14 days after conception.
occurs from two to eight weeks after conception. Support
systems for cells form, and organs appear. Mass of cells is now an embryo and
three layers of cells form. Endoderm is the layer of inner cells, which will
develop into the digestive and respiratory systems. Ectoderm is the outermost
later which will become the nervous system, sensory receptors (ears, nose, and
eyes) and skin parts (hair and nails) Mesoderm is the middle layer, which will
become the circulatory system, bones, muscles, excretory system, and
Organogenesis is the name given to the process of organ formation
during the first two months of prenatal development.
begins two months after conception and lasts for seven months
on average. 3 months after
(fetus is 3 inches long and weighs 3 ounces) 4
(fetus is 6 inches long and weighs 4 to 7 ounces) 5 months after
(fetus is 12 inches and weighs close to a pound) 6 months after
eyelids completely formed, fine layer of hair covers head) 7 months after
(fetus is 16 inches long and about 3 pounds. Considered viable – able to
survive outside the womb) 8 and 9 months after
(fetus gains about 4 extra
pounds). At birth
(average American baby weighs 7.5 pounds and is 20 inches
EQUAL PERIODS OF 3 MONTHS ARE CALLED TRIMESTERS.
NOT THE SAME AS PRENATAL PERIODS
Germinal and Embryonic periods occur in 1
Fetal begins towards the end of the first trimester and continues
through the 2
Hazards to Prenatal Development
is any agent that can potentially cause a birth defect or
negatively alter cognitive and behavioral outcomes. Teratogens
include drugs, incompatible blood types, environmental pollutants,
infectious diseases, nutritional deficiencies, maternal stress, advanced
maternal and paternal age, and environmental pollutants.
The dose, genetic susceptibility, and time of exposure to a
particular teratogen influence both the severity of the damage
to an embryo or fetus and the type of defect