chapter 4: prenatal development

Question 1

prenatal development

Answer 1

the development of humans before they’re born

Question 2

postnatal development

Answer 2

the development of humans after they’re born, especially in infancy

Question 3

stages of prenatal development

Answer 3

o Zygote – first two weeks
o Embryo – 2-10 weeks (the period when organs develop)
o Foetus – after week 10 until birth

Question 4

indirect methods for studying prenatal development

Answer 4

non-human models of prenatal changes in brain and behaviour + human embryos and foetuses that died + testing perception and memory of neonates (infants who’re less than a month old)

Question 5

direct methods of studying prenatal development

Answer 5

measurement of autonomic nervous system activity with external stimulation + phenotypes (characteristics, capacities and patterns of activity) + placing a foetal ultrasound cardiotocograph sensor around the maternal abdomen that can record the heartrate and movement + using fMRI and MEG

Question 6

aproptosis

Answer 6

programmed death of cells

Question 7

when does organogenesis end

Answer 7

8 weeks

Question 8

stages of zygote

Answer 8

o Zygote – day 1, fertilized egg
o Morula – day 3, ball of 16 cell, cell differentiation starts
o Blastula – day 4-7, cavity arises, embryo arises out of inner cells, implantation in uterus

Question 9

what’s gastrulation

Answer 9

formation of the 3 germ layers by migration and differentiation of blastula cells

Question 10

layers of blastula cells

Answer 10

ectoderm - skin, hair and nervous system
mesoderm - muscles and bones
endoderm - most other organs

Question 11

neurulation

Answer 11

ectoderm - neural plate (18 days) - neural tube (cranial-caudal organization)

Question 12

when are cells for different parts of the brain differentiated

Answer 12

18 days

Question 13

what happens when the closing of the neural tube fails

Answer 13

spina bifida (open back) + anencephaly or open skull (usually miscarriage or death shortly after birth)
folic acid during first 12 weeks - helps

Question 14

neurogenesis

Answer 14

the birth of neurons

Question 15

cerebral cortex

Answer 15

the area of the brain that is associated with complex tasks (memory, language, thoughts, control and integration of movement and the senses)

Question 16

when do cerebral hemispheres begin to arise

Answer 16

9 weeks

Question 17

when do the cells in the cerebral hemisphere proliferate and migrate

Answer 17

4 months

Question 18

when is the surface no longer smooth and what appears then

Answer 18

6 months, sulci (groove), gyri (ridges)

Question 19

when does the process of inhibition become function and what happens then

Answer 19

15 weeks - period of reorganisation of behaviours – reflexive neuronal circuits are still in place, now controlled by more sophisticated nerve cells in the new higher centres

Question 20

when is the number of cells in the cerebral cortex mature

Answer 20

27 weeks - but at birth the brain is only at about 25% of its full adult volume (myelination)

Question 21

lobes and their function

Answer 21

Frontal lobes – associated with movement, parietal lobes – sensations, temporal lobes – hearing, memory, sense of self and time, occipital lobes – visual centre of the brain
+Association cortex – surrounds the primary sensory areas, longer development (concerned with higher cognitive and integrative function that develop with experience)

Question 22

what brain regions are the same and different than adult?

Answer 22

Same – sensory and motor networks
Different – emotion and control

Question 23

pattern of rest and activity at 34 weeks

Answer 23

20-30% of their time in quiet, motion-less sleep with a steady heartbeat and breathing movements that are rhythmic
rest of the time - the same as newborn active sleep - many different body movements, eyes moving rapidly back and forth + heart and breathing rate are irregular + responsive to the sensory stimuli they’re exposed to +fewer general body movements + breathing movements

Question 24

does the baby move at 38 weeks

Answer 24

longer periods of deep sleep - rest periods of about 80-100 minutes

Question 25

development of touch

Answer 25

8 weeks – if the area around the lips is stroked – foetuses will respond by moving 10 weeks – foetuses will curl their fingers in a reflexive grasp when their palm is touched 12 weeks – their toes will curl when soles are touches

Question 26

rooting reflex

Answer 26

the reflex that causes newborn babies to respond to one of their cheeks being touched by turning their head in that direction – helps them nurse

Question 27

chemosensory system

Answer 27

encompasses both the gustatory (taste) and olfactory (smell) senses

Question 28

how can infants experience taste stimulants

Answer 28

mouth, nose, blood

Question 29

when are nose plugs gone

Answer 29

4th month

Question 30

when is the constitution of amniotic fluid is increasingly dependent on foetal urination

Answer 30

second ja; f pf tje [regmamcu

Question 31

are some taste preferences learned in utero

Answer 31

yes, newborns turn their heads in the directions of smells present in their mother’s diet (anise, garlic, carrot juice)

Question 32

colostrum

Answer 32

the breast fluid that comes before true milk – rich in minerals and antibodies, helps populate the newborn’s gut with good bacteria

Question 33

vestibular system

Answer 33

the sensory system that contributes to balance and spatial orientation

Question 34

when do infants show the righting reflex and what is that useful for

Answer 34

25 weeks - turning their heads downwards for birth

Question 35

when do babies move

Answer 35

when the mother isn't - vestibular stimulation

Question 36

preterm

Answer 36

born prematurely, anything before 38 weeks

Question 37

what's improved if the incubator is rocked

Answer 37

weight gain, visual responsiveness, and later expressive language development

Question 38

circadian rhythm

Answer 38

bodily cycles within the body that occur on a 24-hour cycle

Question 39

what's kangaroo care

Answer 39

skin-to-skin contact between the mother and the preterm infant over 24 days

Question 40

when are eyelids no longer fused shut

Answer 40

5-7 months

Question 41

when do eyes start forming

Answer 41

5th week

Question 42

how do eyes develop

Answer 42

balloons fold inwards, retina develops (function – capture the light entering the eye through rods and cones (develop from the optic cup) and convert it into electrical impulses) + the outer wall forms a pigment-containing layer that absorbs the light + nutritive network of blood vessels

Question 43

timeline of eye development

Answer 43

2nd month – the lens begins to develop + the eyelids and muscles that move the eyes + the iris 3rd month – the eyelids have fused together + the cornea is forming layers 6th month – all the muscles that move the eyeball are in place 16th to 23rd week - eye movements begin

Question 44

can premature babies see

Answer 44

26 weeks yes - distinguish light from datk

Question 45

the visual pathway

Answer 45

connects the light-sensitive cells in the eye (rods and cones) to the brain – deals with the transmission and interpretation of the electrical impulses encoding the visual information that enters the eye

Question 46

what's the relay station

Answer 46

lateral geniculate nucleus of the thalamus

Question 47

when do the nerve fibbers interconnect with the LGN

Answer 47

end of the first ttimester

Question 48

straite cortex

Answer 48

in the occipital lobe, part of the brain concerned with basic visual function Surrounding areas – perceptual processes – interpretation of sensory information (development by the end of the third trimester)

Question 49

when does the development of the auditory system begin

Answer 49

6th week

Question 50

what can fetuses hear

Answer 50

mother’s heartbeats, borborygmi (gastrointestinal sounds), mother’s voice

Question 51

when do foetal motor and heart rate responses to external sounds start

Answer 51

26th week

Question 52

transnatal learning

Answer 52

learning that occurs during the prenatal period which is remembered during the postnatal period

Question 53

what was found about habituation in the prenatal period

Answer 53

35th week is important 35-37 weeks habituated and dishabituated, 32-34 weeks just mostly habituated

Question 54

research on hearing heartbeats

Answer 54

Intrauterine sounds calm neonates – but some research called the soothing effect of heartbeat sound into question (failure to replicate + neonatal arousal response to sound dependents upon many variables such as characteristics of the stimulus, infant’s initial state and the experimenter’s choice of response)

Question 55

how do infants react to mother's voice compared to a stranger's voice 2 hours after birth

Answer 55

more movement + sucked to activate the recording of it more frequently

Question 56

when can infants discriminate languages

Answer 56

4 days after birth, 2 days old show a preference for their maternal language

Question 57

critical period

Answer 57

Period with specific development is optimal (sensitive period) Period in which system is vulnerable for lesions

Question 58

perinatal

Answer 58

just before and after birth

Question 59

breakdown of congenital defects

Answer 59

10-15% - genetic factors 10% - environmental agents

Question 60

what causes chromosomal defects

Answer 60

an error in the separation of chromosomes into appropriate daughter cells: meiotic cell division – the type of cell division that occurs in sexually reproducing organisms which halves the number of chromosomes in reproductive cells

Question 61

risk for Down's syndrome by age

Answer 61

at 20 is 1/2000, at 30 it’s 1/1000, by 37 it’s 1/200

Question 62

what can the age of the father cause

Answer 62

schizophrenia, autism, dwarfism

Question 63

autosomal genetic disorders and examples

Answer 63

resulting from a mutation in a gene in one of the non-sex chromosomes Sickle cell disease, cystic fibrosis, Tay-Sachs disease, Huntington’s disease, Marfan syndrome Ashkenazi Jews – 1/30 is a carrier of Tay-Sachs disease, African Americans – 8/100 carriers of the sickle cell gene

Question 64

adverse outcomes of heavy maternal alcohol consumption

Answer 64

risk for spontaneous abortion, stillbirth, premature placental separation, intrauterine growth restriction, preterm birth, poor development, newborn mortality + risk for SIDS

Question 65

how many children of Addis get foetal alcohol syndrome

Answer 65

6%

Question 66

factors linked to severity of FAS

Answer 66

mother’s drinking behaviour (hard to say how much is harmful), timing of the consumption, mother’s alcohol metabolism (faster digestion – less damage), mother’s age, genetic predisposition, mother’s lifestyle

Question 67

prenatal influence of smoking

Answer 67

Babies weigh 100-200g less + twice the risk for foetal growth restrictions + risk for prematurity and perinatal complications (premature detachment of the placenta) + two to threefold increase for SIDS + o Behavioural problems and cognitive weakness + problems with attention, visuoperceptual processing and speech processing

Question 68

SSRI

Answer 68

Selective serotonin reuptake inhibitior (SSRI) – a class of drugs used to treat depression or anxiety

Question 69

microcephaly

Answer 69

small skull, limited brain growth (often in combination with intellectual disability and organ defects) - Zika virus: spread by mosquitoes, >1000 cases where the mother was infected and the child developed microcephaly

Question 70

what are calcium and iron needed for

Answer 70

calcium - for foetal bone, muscle and transmitter production iron - red blood cell and tissue production

Question 71

developmental programming

Answer 71

the hypothesis that prenatal conditions have detrimental effects on health into adulthood

Question 72

timing of nutrition - diseases

Answer 72

o Early – diabetes, CVD, breast cancer, depression, schizophrenia, obesity o Middle – diabetes, lung diseases, kidney diseases o Late – diabetes

Question 73

dutch pregnant women in WWII

Answer 73

risk of having schizophrenia, antisocial personality disorder or mood disorder (2nd and 3rd trimester)

Question 74

reflex behaviors at birth

Answer 74

breathing, rooting, sucking, swallowing + toe-curling reflex, finger-grasping reflex, startle reflex + stepping reflex