Humans Development Outline
K. Prenatal development and birth
1. Prenatal development (3 periods or 3 trimesters)
2. Birth: the big day (welcome to the outside world)
3. Postpartum period (after birth
L. Prenatal development is divided into 3 periods and lasts approximately 266
days (9 months)
1. Germinal period: first 2 weeks after conception, zygote created
2. Embryonic period: 2-8 weeks after conception
3. Fetal period: 2 months after conception
M. The three trimesters of prenatal development
1. First trimester: conception-15 weeks
a. Less than 1/10 of an inch long
2. Second trimester: 16 weeks-27 weeks
a. About 5.5 inches long & 4 ounces
3. Third trimester: 28 weeks-40 weeks
a. About 14-17 inches long & 2.5-3 pounds
N. Teratogen
1. Any agent that causes birth defects
a. Drugs (prescription & nonprescription)
b. Alcohol or tobacco
c. Environmental pollutants
d. Infectious diseases
e. Nutritional deficiencies
f. Maternal stress
g. Advanced age of parent
2. Severity of damage to the unborn depends on:
a. Dose
b. Time of exposure
c. Genetic stability
O. Theories of development
1. Erik Erikson - exploring psycho-social changes
a. A little like the unfolding of a rose bud, each petal opens up
at a certain time, in a certain order, which nature, through its
genetics, has determined. If we interfere in the natural order
of development by pulling a petal forward prematurely or out
of order, we ruin the development of the entire flower.
K. Prenatal development and birth
1. Prenatal development (3 periods or 3 trimesters)
2. Birth: the big day (welcome to the outside world)
3. Postpartum period (after birth
L. Prenatal development is divided into 3 periods and lasts approximately 266
days (9 months)
1. Germinal period: first 2 weeks after conception, zygote created
2. Embryonic period: 2-8 weeks after conception
3. Fetal period: 2 months after conception
M. The three trimesters of prenatal development
1. First trimester: conception-15 weeks
a. Less than 1/10 of an inch long
2. Second trimester: 16 weeks-27 weeks
a. About 5.5 inches long & 4 ounces
3. Third trimester: 28 weeks-40 weeks
a. About 14-17 inches long & 2.5-3 pounds
N. Teratogen
1. Any agent that causes birth defects
a. Drugs (prescription & nonprescription)
b. Alcohol or tobacco
c. Environmental pollutants
d. Infectious diseases
e. Nutritional deficiencies
f. Maternal stress
g. Advanced age of parent
2. Severity of damage to the unborn depends on:
a. Dose
b. Time of exposure
c. Genetic stability
O. Theories of development
1. Erik Erikson - exploring psycho-social changes
a. A little like the unfolding of a rose bud, each petal opens up
at a certain time, in a certain order, which nature, through its
genetics, has determined. If we interfere in the natural order
of development by pulling a petal forward prematurely or out
of order, we ruin the development of the entire flower.
