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