Intro & Prenatal Development Flashcards
What is developmental psychology?
The study of change and stability over the lifespan
Specifically how we change physically, cognitively, behaviourally and socially over time due to biological, individual and environmental differences
What is ontogenetic development?
The development of an individual over their lifetime
What is microgenetic development?
Changes that occur over very brief periods of time
What is phylogenetic development?
Changes that occur over evolutionary time
When is the prenatal stage of development?
Conception to birth
When is the infancy stage of development?
Birth to 2 years
When is the preschool stage of development?
2 to 4 years
When is the childhood stage of development?
5 to 12 years
When is the adolescence stage of development?
12 to 18 years
When is the young adulthood stage of development?
18 to 40 years
When is the middle - late adulthood stage of development?
40 - 65 years
65 years and over
What is preformationism?
The popular belief that miniature people lived in sperm and started to grow when the sperm met the egg
What is Epigenesis?
The term describing that new organs and structures develop through a series of stages throughout prenatal development
When does the Germinal stage take place?
Conception - 2 weeks
What happens during the germinal stage?
The fertilised egg (zygote) doubles its cells twice a day
Around 2 weeks after fertilisation, the zygote attaches to the uterus wall and the cells become an embryo
Fewer than half of zygotes survive
When does the Embryo stage take place?
2 - 8 weeks
What happens during the embryo stage?
A period of rapid growth when key organs and structures develop
The inner cell mass become the embryo and the rest becomes the amniotic sac and the placenta
What is the amniotic sac?
A membrane filled with clear fluid which provides an even temperature and cushioning
What is the placenta?
It permits the exchange of materials from the mother to the embryo/foetus via the bloodstream through blood vessels that make up the umbilical cord
Which three layers are formed from the inner cell mass at the beginning of the embryo stage?
The ectoderm (top layer) The mesoderm (middle layer) The endoderm (bottom layer)
What does the ectoderm become?
The nervous system, nails, teeth, inner ear, lens of eyes and skin
What does the mesoderm become?
The muscles, bones, circulatory system, inner layers of the skin and internal organs
What does the endoderm become?
The digestive system, lungs, urinary tract and glands
Outline the formation of the brain and spinal cord
Once the layers differentiate, a u shaped groove forms down the centre of the ectoderm and the top of the groove fused to form the neural tube
The neural tube becomes the brain and SC
When does the foetus stage take place?
9 weeks - birth
What happens during the foetus stage?
Marks a time in growth and development in the organs
Areas near the head develop earlier
During the last 5 months, the lower parts develop more rapidly
The development of sexual organs takes place early in this period
All human features regardless of whether they are M or F can develop M or F genitalia
Its the presence or absence of androgens that cause M genitalia to develop
How is gender determined?
Whether sperm X or Y fertilises the egg
Outline prenatal sex differences
Sperm that carry Y chromosome are lighter and swim faster, so 120-150 males are conceived to every 100 females
But at birth only 106 males to 100 females
Why are boys more vulnerable prenatally?
Because they only have one X chromosome, so if they have a defective gene on the X chromosome, they do not have a functioning copy to balance this out
What are teratogens?
Environmental agents (drugs), diseases, and physical conditions that can affect the growing embryo/foetus They can impair prenatal development leading to birth defects or prenatal death
What do the effects of teratogens depend on?
Timing - may only cause damage if present during a certain period of development
The dose-response relationship - the greater the exposure, the more likely the damage
What is the most common human teratogen?
Alcohol
What does alcohol do to the foetus?
Crosses the placenta into their bloodstream and amniotic sac
Stays in the foetuses blood stream for longer
Can lead to heightened activity reflexes and abnormal startle reflexes
Can also lead to FAS - facial defects, hyperactivity and behavioural problems
