Week 3 Flashcards
genotype
an individual’s inherited genetic makeup
phenotype
the individual’s appearance and behavior, shaped in part by genotype
what are the 4 time periods of a zygote to newborn
- germinal period
- embryonic period
- fetal period
- age of viability
Germinal period
- first 14 days
- zygote begins duplication and division within hours of conception
- development of the placenta
- implantation (10 days after conception)
- organisms growth rapidly
Embryonic period
- 3 to 8 weeks
- primitive streak becomes the neural tube and later forms the brain and spine of the CNS
- head takes shape
- eyes, ears, nose, and mouth form
- heart begins to pulsate
- extremities develop and webbed finger and toes separate
fetal period
- 9 weeks to birth
- genitals form and sex hormones cause differences in fetal brain organization
- by 3 months, the fetus weighs about 3 ounces
- experiences the period of greatest brain growth during the 4th, 5th, and 6th months
age of viability
- age at which a preterm newborn may survive outside the mother’s uterus if medical care is available
- 22 weeks after conception
- brain is able to regulate basic body functions
teratogens
- includes any agent or condition, including viruses, chemicals, and drugs, resulting in birth defects or death
- critical period
- threshold
preterm
- birth that occurs two or more weeks early
- usually associated with low birthweight
Small for gestational age (SGA)
- these newborns should weigh much more at their GA than they do
- suggests impairment throughout prenatal development and serious problems
Causes for LBW
- maternal malnutrition and behavior
- hunger; poor nutrition
- drug use
- multiple births
weight and height at 24 months
weight doubles & child will reach half the adult height
brain percentage at birth
25 % of adult weight
brain percentage at 24 months
75% of adult weight
head sparing
preserves brain weight over body weight when calorie intake dips
motor skills
different ways in which the body uses muscles to preform specific tasks
fine motor skills
use smaller muscles, specifically those in the hand and wrist
- includes grasping skills as well as eye-hand coordination
gross motor skills
use larger muscle and muscle groups
- includes rolling, crawling, walking
Implicit memory
- not verbal
-memories stored in parts of the brain that develop first - evident by 3 months; effects are lifelong
explicit memory
- depends on language
- arises in cerebral cortex
- improves along with language acquisition
- vocabulary depends on explicit memory
naming explosion
- child’s vocabulary spurts, once 50 words are mastered
- 21 months old says 2x as many words as 18 month old
theory one for language learning
infants need to be taught to use words (BF skinner)
theory two for language learning
- social impulses foster language learning
- only humans learn language to join the social world
- language learning is more effective from books than from videos
theory three for language learning
- babies are born with a genetic “language acquisition device,” pruned after the sensitive language learning period
- genetically programmed to learn our first language and its structure
experience-expectant growth:
- basic experiences are necessary for the brain to grow normally
- all babies brains need things to see and hear, objects to manipulate, people to love
experience- dependent growth:
- human brains are plastic
- neural connection grow in response to experiences that vary by culture
