prenatal development 2 Flashcards
which is the first sense to develop?
touch
foetus moves if area around lips is touched at how many weeks?
8
at 10-12 weeks what happens when the palm and soles of feet are touched?
curl their fingers and toes
what do foetuses initially do when responding to facial touch that is different to later in development?
initially move head away from touch, later towards touch
once the foetus starts moving around what areas do they touch?
uterine wall, umbilical cord, themselves
why do foetuses touch their face more than any other part of the body?
provides wide variety of physical sensations > promote further development of physical sensation and touch
what 2 senses are part of the chemosensory system?
taste and smell
when does smell start to develop?
6-7 weeks
when does taste start to develop?
13-15 weeks
what stimulates the chemosensory system?
substances in the amniotic fluid
foetuses ______ and ______ amniotic fluid as it is important for stimulation of the chemosensory system
swallow, inhale (from 4 months)
what is another chemosensory route other than amniotic fluid and how does it get to the foetus?
VIA BLOOD > odour and taste molecules pass from mothers blood stream > placenta > foetus circulation system
why are the molecules via the blood more intense than from amniotic fluid?
haven’t been broken down or metabolised
foetal blood flows through nose and mouth through _______ _______
sensory receptors
what is the evidence that a foetus shows a preference for sweet taste?
mother has a meal so increased glucose levels > amniotic fluid tastes sweeter > foetus will swallow more regularly than if it contains bitter substances
do foetuses have the ability to detect and have preference t certain flavours?
yes! may be genetically determined, learnt in utero, neonates turn their heads to odourants that have been present in mothers diet
what did Mennella et al (2001) show about experience with a flavour in amniotic fluid/breast milk?
it can modify an infants acceptance and enjoyment of similar foods
what has exposure to alcohol in the womb shown?
to increase swelling > may cause preference for alcohol later in life
sensory system that contributes to balance and spatial orientation =
vestibular system
how is info of motion sensed by the vestibular system?
3 fluid filled canals in inner ear that when movement occurs the fluid moves > detected by tiny hairs in the canals > sent to brain to be processed
what does the vestibular system have an important role in?
changing arousal states
what happens when the mother moves a lot?
foetus receives lots of vestibular info
why is it good to rock a baby to sleep at night?
activates the vestibular system and changes arousal state to sleep
eyelids are shut and don’t open until when?
5-7 month gestation
what happens if preterm babies experience light too early and what can be done?
subtle visual deficits so a period of darkness may be needed for proper visual development
what is the visual system like at 5 weeks in utero?
2 balloon like structures at sides of front brain, become separated by small stalk where nerves will travel between eyes and brain > balloons then fold to form a 2 layers to be the retina
when does the lens, eyelids and eye muscles develop?
at 2 months
when do the eyelids fuse together?
at 3 months
what has developed at 6 months in the visual system?
all eye muscles are in place
when do eye movements start?
between 16-23 weeks
nerve fibres connect with the LGN = end of __ trimester
1st
what allows info from both eyes to be integrated at 9 weeks of pregnancy?
partial cross over of the fibres of the optic nerve
at how many weeks is the crossing over of optic nerve fibres complete?
15 weeks
why are REM and sleep patterns important of the development of the visual pathway and visual cortex?
connection between retina and brain is vital for vision, help messages from the retina sync with brain waves of visual cortex
what happens if the infant is deprived of sleep and REM and sleep cycles are disrupted?
can significantly interfere with visual development
why is it a good thing that when babies are born they are near sited?
can see close up of their mum which will strengthen the attachment bond
at how many weeks does the auditory system start to develop?
6 weeks (will start to hear low frequency internal sounds of mothers organs and voice)
inner ear begins to develop to sense balance and position = how many weeks?
8 weeks
when does the cochlea start to develop?
9 weeks
when does the vestibular system start to work?
14 weeks
at 23-25 weeks the auditory system is mature enough to detect _______ stimulation
vibroacoustic
why is the ability to hear still very limited in utero?
sound has to pass through maternal tissue so cuts out higher frequencies
when is sound reliably detected?
30 weeks
what is key for parts of the brain that deal with multimodal stimulation as several senses are activated?
sound stimulation
learning that occurs during the prenatal period which is remembered during the postnatal period =
transnatal learning
what the embryo/foetus is exposed to _______ is important for development ______
prenatally, postnatally
how do we test prenatal learning?
during foetal period present stimulus and test babies responses for habituation or dishabituation
what did Morokuma find in his prenatal auditory learning study?
at 35-37 weeks > foetus habituated and dishabituated but 32-34 weeks had more varied responses and no dishabituation (SHOWS 35 WEEKS MARKS IMPORTANT ADVANCE IN LEARNING ABILITY)
what have studies shown about newborns preferring their mothers voice?
react with more movement to mothers vs strangers voice, sucked on pacifier more frequently to activate mothers voice
(preterm babies didn’t show this)
what study has shown the best evidence for transnatal learning?
mums read out look book for last 1.5 months of pregnancy, changes in sucking rate turned on and off recorder of mothers reading. half read same story, half read different. infants modified sucking rate in direction that produced the familiar story
perinatal complications =
complications in the period before and just after birth
what are the risks for foetal development?
genetic factors, environmental agents, rest congenital anomalies (result of gene and environment interactions), chromosomal abnormalities, miscarriages
what dramatically increases chromosomal abnormalities in the risk of down syndrome development?
maternal age
risk of down syndrome is 1 in ____ at age 20, but 1 in ___ by age 37
2000, 200
what factors give women a basic sense of security that appear to enhance the prospects of a healthy baby?
presence of sympathetic mate, supportive family members, adequate housing, steady employment
what 2 factors during pregnancy are associated with premature delivery and low birth weight?
psychological stress, low SES
what are some of the issues with teenage pregnancy?
pregnant girls growth not complete, pelvic cradle not ready, stress, maternal malnutrition
maternal malnutrition is related to what 2 things?
premature birth, low birth weight
what can be reduced if folic acid is taken during pregnancy?
risk of spina bifida (neural tube defect)
give some examples of teratogens
certain drugs taken by mother, x-rays, environmental contaminants, infectious organisms, diseases (rubella/syphilis), radiation, pollution
what causes abnormal growth of the placenta?
nicotine
what are foetal development risks associated with smoking?
increased rate of spontaneous abortion/stillbirth/neonate death, low birth weight, lung problems, asthma, developmental problems, short attention span, learning/behaviour problems
what is the leading cause of mental retardation?
alcohol
what does maternal alcohol use lead to?
fetal alcohol syndrome (FAS)
what are some features of FAS?
abnormally small head, underdeveloped brain, eye abnormalities, congenial HD, joint abnormalities, face malformations
when is the most serious damage from alcohol caused?
1st weeks of pregnancy
