 Conception
– 4 weeks
8
weeks
 12 weeks
 16
weeks
 20 weeks
 24 weeks
 28
weeks
 32 weeks
 36 - 38 weeks
 Less
1/10 inch long
 Beginning of spinal cord, nervous system,
heart, intestinal system and lungs
 Amniotic Sac – clear fluid, in which the
unborn baby floats and moves
 Less
than 1 inch
 Face forming – eyes, ears, mouth
 Arms and legs are moving
 Heartbeat detectable
3
inches and weighs 1 oz
 Moving fingers and toes
 Finger prints
 Can smile, frown, swallow and urinate
5
½ inches long, 4 oz
 Strong heartbeat
 Thin skin
 Downy hair over body
 Fingernails and toe nails develop
 10-12
inches
 Sucks thumb
 Hiccup
 Hair, eyelashes and eyebrows
 Rolls over fluid
 11-14
inches 1 ½ lbs
 Wrinkled skin
 Open eyes
 Strong grip
 14-17
inches, 2 ½ - 3 lbs
 Adding body fat
 Very active
 16
½ - 18 inches, 4 – 5 lbs
 Sleep/awake
 Responds to sounds
19 inches 6lbs
 Skin less wrinkled
 Gaining immunities from mother

 Embryonic


Occurs 2-8 weeks after conception
Rate increases of cell division, support systems
for the cells form, organs appear
 Germinal


Period
period
Takes place in first 2 weeks after conception
Creation of zygote (fertilized egg), cell division
attachment of the zygote to the uterine wall
 Embryonic



Period
Occurs 2-8 weeks after conception
Rate increases of cell division, support systems for
the cells form, organs appear
The mass of cells attached to the uterine wall forms
three layers and is now called the embryo
 Endoderm – inner layer of cells will develop into
digestive and respiratory systems
 Ectoderm – outer layer of cells will become the
nervous systems and sensory receptors (ears, nose,
eyes and skin)
 Mesoderm – middle layer – will develop into the
circulatory system, bones, muscle, excretory system
and reproductive system
 Fetal



Period
2 months of conception
Last for 7 months
Development is very dramatic