DEVELOPMENTAL PSYCHOLOGY
PSYC105
MODULE 2: BEGINNING OF LIFE
(Pre-natal Period and the Cultural Beliefs about Pregnancy)
(Growth, Development and Maturation)
FORMING A NEW LIFE
o Endoderm – the inner layer, will become the
Conception – occurs when a single sperm cell from
digestive system, liver, pancreas, salivary
the male unites with an ovum (egg) in the female’s
glands, and respiratory system.
fallopian tube in a process called fertilization.
o Mesoderm – the middle layer, will develop
Course of Prenatal Development and differentiate into the layer of skin,
(Growth, Development and Maturation)
muscles, skeleton, and excretory and
- Typical prenatal development begins with circulatory systems.
fertilization and ends with birth, lasting between 266 • Other parts of the blastocyst begin to develop into
and 280 days (from 38 to 40 weeks). It can be divided organs that will nurture and protect development
into three periods: germinal, embryonic, and fetal. in the womb:
o Amniotic sac – a fluid filled membrane that
• Cephalocaudal principle – “head to tail,”
encases the developing embryo, protecting it
from head to lower part of the trunk
and giving it room to move and grow.
• Proximodistal principle – “near to far” from
o Placenta – allows oxygen, nourishment, and
center of the body to outer ones.
wastes to pass between mother and embryo
GERMINAL PERIOD o Umbilical cord – Nutrients from the mother
pass from her blood to the embryonic blood
• Germinal Period – Is the period of prenatal
vessels, which carry them, via the umbilical
development that takes place in the first two
cord, to the embryo.
weeks after conception.
• It includes the creation of the fertilized egg, called EMBRYONIC STAGE
a zygote, cell division, and the attachment of the (2-8 weeks)
zygote to the uterine wall.
• Embryonic Stage – the organs and major body
• Rapid cell division (mitosis) by the zygote
systems—respiratory, digestive, and nervous—
continues throughout the germinal period
develop rapidly (Organogenesis).
• By approximately one week after conception, the
o This is a critical period, when the embryo is
differentiation of these cells—their specialization
most vulnerable to destructive influences in
for different tasks—has already begun.
the prenatal environment.
o At this stage, the group of cells, now called the
• The most severely defective embryos usually do
blastocyst, consists of an inner mass of cells
not survive beyond the first trimester, or 3-
that will eventually develop into the embryo.
month period, of pregnancy.
o Trophoblast – an outer layer of cells that later
• Spontaneous abortion, commonly called a
provides nutrition and support for the embryo
miscarriage, is the expulsion from the uterus of
• Implantation – attachment of the zygote to the
an embryo or fetus that is unable to survive
uterine wall, takes place about after conception.
outside the womb.
• Before implantation, as cell differentiation
• A miscarriage that occurs after 20 weeks of
begins, some cells around the edge of the
gestation is generally characterized as a stillbirth.
blastocyst cluster on one side 11 to 15 days to form
the embryonic disk, a thickened cell mass from FETAL STAGE
which the embryo begins to develop. (8 weeks - birth)
o Ectoderm – the upper layer, will become the
• The appearance of the first bone cells at about 8
outer layer of skin, the nails, hair, teeth,
weeks signals the beginning of the fetal stage.
sensory organs, and the nervous system,
including the brain and spinal cord.
PSYC105
MODULE 2: BEGINNING OF LIFE
(Pre-natal Period and the Cultural Beliefs about Pregnancy)
(Growth, Development and Maturation)
FORMING A NEW LIFE
o Endoderm – the inner layer, will become the
Conception – occurs when a single sperm cell from
digestive system, liver, pancreas, salivary
the male unites with an ovum (egg) in the female’s
glands, and respiratory system.
fallopian tube in a process called fertilization.
o Mesoderm – the middle layer, will develop
Course of Prenatal Development and differentiate into the layer of skin,
(Growth, Development and Maturation)
muscles, skeleton, and excretory and
- Typical prenatal development begins with circulatory systems.
fertilization and ends with birth, lasting between 266 • Other parts of the blastocyst begin to develop into
and 280 days (from 38 to 40 weeks). It can be divided organs that will nurture and protect development
into three periods: germinal, embryonic, and fetal. in the womb:
o Amniotic sac – a fluid filled membrane that
• Cephalocaudal principle – “head to tail,”
encases the developing embryo, protecting it
from head to lower part of the trunk
and giving it room to move and grow.
• Proximodistal principle – “near to far” from
o Placenta – allows oxygen, nourishment, and
center of the body to outer ones.
wastes to pass between mother and embryo
GERMINAL PERIOD o Umbilical cord – Nutrients from the mother
pass from her blood to the embryonic blood
• Germinal Period – Is the period of prenatal
vessels, which carry them, via the umbilical
development that takes place in the first two
cord, to the embryo.
weeks after conception.
• It includes the creation of the fertilized egg, called EMBRYONIC STAGE
a zygote, cell division, and the attachment of the (2-8 weeks)
zygote to the uterine wall.
• Embryonic Stage – the organs and major body
• Rapid cell division (mitosis) by the zygote
systems—respiratory, digestive, and nervous—
continues throughout the germinal period
develop rapidly (Organogenesis).
• By approximately one week after conception, the
o This is a critical period, when the embryo is
differentiation of these cells—their specialization
most vulnerable to destructive influences in
for different tasks—has already begun.
the prenatal environment.
o At this stage, the group of cells, now called the
• The most severely defective embryos usually do
blastocyst, consists of an inner mass of cells
not survive beyond the first trimester, or 3-
that will eventually develop into the embryo.
month period, of pregnancy.
o Trophoblast – an outer layer of cells that later
• Spontaneous abortion, commonly called a
provides nutrition and support for the embryo
miscarriage, is the expulsion from the uterus of
• Implantation – attachment of the zygote to the
an embryo or fetus that is unable to survive
uterine wall, takes place about after conception.
outside the womb.
• Before implantation, as cell differentiation
• A miscarriage that occurs after 20 weeks of
begins, some cells around the edge of the
gestation is generally characterized as a stillbirth.
blastocyst cluster on one side 11 to 15 days to form
the embryonic disk, a thickened cell mass from FETAL STAGE
which the embryo begins to develop. (8 weeks - birth)
o Ectoderm – the upper layer, will become the
• The appearance of the first bone cells at about 8
outer layer of skin, the nails, hair, teeth,
weeks signals the beginning of the fetal stage.
sensory organs, and the nervous system,
including the brain and spinal cord.
