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Stages of development: Prenatal. - Coggle Diagram
Stages of development: Prenatal.
Foetal behavioural states.
Sensory development: Senses emerge in the womb, shaping foetal learning and preparing for life outside of the womb.
Environmental risks: Factors can negatively impact foetal development, emphasising the importance of prenatal care.
Foetal behaviour: Foetuses exhibit distinct behavioural states that reflect neurological development.
Newborn reflexes: Primitive and postural reflexes are crucial survival tools for newborns and form the foundation for later voluntary movement development.
Life-cycle theories: Key assumptions.
Assumption 2: The epigenetic principle.
Each stage has a unique crisis or challenge.
Successful resolution is essential for healthy development at later stages.
Failure to resolve a crisis cannegatively impact later physical, cognitive, social, or [sychological well-being.
Assumption 3: Defining features.
Each stage has a dominant characteristic or critical turning point that sets it apart from the rest.
Assumption 1: Sequential stages.
Development progresses through distinct, predefined stages in an unchanging order.
Prenatal period: Foundation for life.
The most rapid growth phase, transforming a single cell into a complex baby.
Development is complex and shaped by environmental influences that can impact the function of developing organs.
A newborn's age starts at zero, marking the transition from prenatal development.
Culture shapes us: Birth, death, and beyond.
African context: A strong connection to ancestry and cultural heritage shapes perspectives on life and death.
Discussion point: How can cultural or social practices influence beliefs about birth, death, and loss of kids.
Culture influences how we think, feel, and behave - including how we understand and experience health, development, and the entire life cycle.
Key debates.
Continous vs. discontinous development.
Does prenatal development progress smoothly and gradually or occur in distinct stages with marked changes?
Consider how different development theories might support one view or the other.
Functions of foetal behaviour.
What is the purpose of foetal movements and behaviours?
Theories that foetal behaviours aid in development, prepare for life outside the womb or simply reflect a maturing nervous system.
link to focus: Continued development and refinement of
Nature vs. nurture.
To what extent is prenatal development shaped by innate biological factors vs. environmental influences?
Explores the interplay between genetics and experiences within the womb.
Three stages of prenatal development.
Embryonic period (+3 to 8 weeks).
Development is extremely rapid and vulnerable to disruption.
The embryo is highly susceptible to the influence of teratogens.
Major organs and body systems begin to form.
Foetal period (+9 weeks to birth).
Sensory systems develop, and the foetus begins to respond stimuli.
Greater movement and behavioural patterns emerge.
Focus shifts to the continued growth and refinement of existing structures.
Germinal period (Conception to +weeks).
The fertilised egg (zygote) undergoes rapid cell devision.
Travels down the fallopian tube and implants into the uterine lining.
It begins with fertilisation when sperm and egg unite.
Germinal period: Initiating development.
Key events.
Implantation: The blastocyst embeds in the uterine lining, establishing the foundation for development.
Placenta formation: The initial placenta develops, providing vital nutrients and oxygen to the embryo.
Rapid cell division: The zygote divides, forming the morula and then the blastocyst (a hollow ball of cells).
Hormone production: The blastocyst secretes hormones to maintain the pregnancy and prevent the mother's immune system from rejecting the embryo.
Fertilisation: Union of sperm and egg in the fallopian tube.
Potential complications.
Ectopic pregnancy: Fertilisation and implantation can occur outside the uterus, posing a significant risk to the mother.
Timeline: Spans from fertilisation to 2 weeks after conception.
Embryonic period: Rapid development and organ formation.
Transformation: Embryo starts to take on a recognisable human form.
Organogenesis: Major organ systems begin to develop through a process of cell specialisation.
Timeline: Extends from the third to the 8th week of pregnancy.
Scientific mystery: While cell differentiation is guided by chemical signals and the surrounding environment, the exact mechanisms controlling this process remain partially understood.
Early heartbeat: Heart begins to beat, and blood circulation is established around the end of week 3, enabling the transport of nutrients and waste.
Critical period: This period is extremely sensitive to disruptions that negatively affect development.
Support systems: The umbilical cord and placenta form during this stage, establishing a vital connection between the mother and developing embryo.
Foetal period: Growth and refinement.
Rapid growth: Significant increase in size, particularly during the third and fourth months.
Focus: Continued development and refinement of structures, preparing the foetus for life outside the womb.
Behavioural foundations: The origins of motor, sensory, and basic learning behaviours emerge.
Key milestones.
Month 3: Differentiation of external genitalia, formation of connections between muscles and the nervous system.
Month 4: Face becomes more human-like, mother starts feeling movement.
Month 5: Increased foetal movement strength.
Month 6: Eyes fully formed.
Month 7: Significant chance of survival if born prematurely due to the development of critical systems.
Months 8-9: Fat deposition for temperature regulation, continued organ maturation, increased antibody transfer from mother, preparation for birth.
Timeline: Begins around week nine of pregnancy and continues until birth.
Developing senses.
Taste: The early gourmet.
Taste buds form early in pregnancy.
The foetus experiences flavours in the amniotic fluid, influencing preferences after birth.
Smell: Building a scent library.
The foetus inhales amniotic fluid, getting scents linked to the mother's diet.
Newborns show a strong preference for their mother's scent.
Develops alongside taste.
Touch: The pioneer.
Spreads throughout the body during the foetal period.
Well-developed at birth, allowing exploration and connection with caregivers.
Develops earliest, beginning around the mouth at approximately 8 weeks.
Hearing: Muffled but meaningful.
The foetus responds to internal and external sounds.
May recognise familiar voices and show preferences for certain music.
Ears develop early and become functional in the second trimester.
Foetal emotions.
Building blocks.
Nervous system and brain areas linked to emotions begin developing.
Foetuses demonstrate basic responses to stimuli.
Primitive focus: Emphasise that early responses likely centre around survival needs and sensations, not complex emotions.
Complexity: Acknowledge the difficulty in defining foetal emotions in the same way we understand adult experiences.
Maternal influence.
A mother's emotional state can impact the foetal environment through hormones and stress responses.
Underscore this is not a direct mirroring of emotions, but highlights a connection between maternal well-being and the foetus.
Principles of prenatal development.
General specific principle: Organs begin with basic structures and characteristics, gradually developing more specialised details and functions.
Importance hierarchy principle: Development prioritises structures and systems crucial for survival before focusing on less essential features.
Cephalocaudal principle: Development progresses from head to toe. Structures near the head are initially more advanced than those further down the body.
Prenatal brain development.
Neural tube origins.
Proper closure of the neural tube around week four is crucial for development.
Brain develops from the neural plate, which folds to form the neural tube.
Potential defects: Failure of the neural tube to close can lead to severe birth defects like spina bifida or anencephaly.
Early start, prolonged development.
Begins early (+ 18 days after fertilisation).
Continues for years post-birth, making it one of the slowest organs to mature.
Two levels of development.
Gross level: Formation of major brain structures from the neural tube.
Micro level: Intricate cellular organisation and connections within the brain.
Prenatal brain development: Gross structural changes.
Neural tube beginnings.
Following closure, the rostral end of the neural tube develops three swellings: forebrain, midbrain, and hindbrain.
Subdivision (Week 4)
Forebrain divides into the diencephalon and telencephalon.
Hindbrain divides into the metencephalon and myelencephalon.
Rapid transformation (Week 5).
The five-part brain structure becomes clearly defined.
Cerebral development (Week 11).
The telencephalon expands significantly, forming the cerebral hemispheres.
Hemispheres initially smooth, later developing characteristic grooves and convolutions.
Prenatal brain development: Cellular complexity.
Neuron production.
Majority of neurons a person will ever have are generated by the end of the second trimester.
Peak production between 10-26 weeks with an incredible rate.
Cell death (Pruning).
Overproduction of neurons is followed by selective cell death (apoptosis).
Pruning eliminates neurons with weak or inappropriate connections, sculpting the brain.
3 Key stages.
Migration: Cells move from their origin in the neural tube to their final locations, guided by radial glial cells.
Myelination and synaptogenesis: Nerve cells develop insulating myelin sheaths and form synapses to enable communication.
Proliferation: Production of nerve cells (complete by the end of the second trimester).
Genetic abnormalities.
Faulty genes: Genetic abnormalities stem from faulty genes that transmit distorted messages, impacting development.
Types.
Sex-linked abnormalities: Occur on the sex chromosomes, like haemophilia.
Ethnically-linked abnormalities: Disorders with higher prevalence within specific ethnic groups due to inheritance of a faulty gene from a common ancestor.
Rarity: Emphasise that while genetic abnormalities can occur, they are uncommon, affecting only a small percentage of live births.
South African examples.
Tay-Sachs disease.
Albinism.
Porphyria.
Thalassemia.
Chromosomal abnormalities.
Down syndrome.
Characterised by intellectual disability, distinctive facial features, a stocky build, and often a pleasant temperament.
Usually caused by Trisomy 21: an extra chromosome on the 21st pair, resulting in a total of 47 chromosomes.
The most common chromosomal abnormality.
Significant impact: Chromosomal abnormalities are a major cause of pregnancy loss.
Teratogens
Diseases as teratogens.
While the placenta provides protection, some pathogens can cross the harm the developing foetus.
Examples: Rubella, AIDS, Syphilis and Genital Herpes.
Substances as teratogens.
Foetal Alcohol Spectrum Disorder: Causes growth, cognitive, and behavioural problems. Severity depends on dosage.
Foetal Tobacco Syndrome: Restricts growth and can negatively impact later cognitive development.
Other drugs: Prescription medications, illicit substances, and even excessive caffeine can be harmful.
Teratology: The field studying the harmful effects of environmental exposure on development.
Timing matters.
Embryonic period: Exposure risks major malformations as organs are forming.
Foetal period: Exposure can impair growth and developmental delays.
Teratogens defined: Substances that can cause developmental abnormalities.
Foetal origins hypothesis: How early life shapes later health.
Programming: Prenatal environment shapes the development and functional capacity of organs.
Predictive adaptive response.
If the foetus experiences poor nutrition, the body adapts to conserve energy and resources.
This prepares the foetus for continued scarcity but can become detrimental if the postnatal environment is plentiful.
Central idea: Prenatal experiences can have long-lasting effects on a person's health throughout life.
Implications.
The Foetal Origins Hypothesis suggests that prenatal conditions can predispose individuals to later health problems like:
Cardiovascular disease.
Diabetes.
Obesity.
Malnutrition: A threat across generations.
Dependency: The foetus relies on the mother's nutrition for healthy development.
Consequences of malnutrition.
Retarded growth, risk of death in infancy, and potential intellectual disabilities.
Heightened susceptibility to infections.
Increased risk of stillbirth, low birth weight, premature birth, and deformities.
Poverty and risk.
Kids in poverty are more vulnerable to physical, cognitive, and developmental problems.
Emphasse the link between poverty and heightened health risks.
Long-term impact.
Malnutrition during critical periods can disrupt organ development.
It can program lifelong metabolic and health issues.
Maternal age and prenatal risks.
Older mothers (35+).
Increased risks with pregnancies after age 40.
Likelihood of longer and more difficult labour and delivery.
Important considerations.
Access to healthcare: Limited access to prenatal care can exacerbate risks for both young and older mothers.
Additional risk factors for older mothers: Pre-existing conditions, chromosomal abnormalities in the fetus.
Teenage mothers.
Highest risk for those 15 years of age and younger.
Increased susceptibility to premature births, stillbirths, and birth complications.
Maternal stress: Impact on prenatal development.
Mechanisms.
Stress hormones like adrenaline and noradrenaline are released in response to the mother's emotional state.
These hormones can cross the placenta, potentially affecting the foetus.
Potential effects.
Research suggests links between maternal stress and:
Increased foetal activity.
Behavioural changes in newborns.
Potential long-term impacts.
Connection: A mother's anxiety or depression can influence the developing foetus and newborn.
Foetal development: Milestones of movement.
Early movements.
Simple reflexes triggered by the spinal cord, cause passive limb movement.
Initial movements were detected much earlier than felt by the mother (around 7 weeks).
Maternal awareness: Mothers typically begin to feel foetal movement between 18-20 weeks.
Foetal behavioural states.
Defining states.
Distinct patterns of behaviour are defined by measurable variables that remain stable over time.
Foetal states are inferred based on similarities with observable newborn states.
The four states.
2F: Active sleep (Frequent movement, eye movement, variations in heart rate).
3F: Quiet awake (No major movement, eye movement, steady heart rate).
1F: Quiet sleep (Minimal movement, stable heart rate).
4F: Active awake (Continuous movement, eye movement, elevated heart rate).
Developing senses in the womb.
Hearing.
Sensitivity to frequency, intensity, and duration of sounds.
Hearing range expands as development progresses.
Womb environment is surprisingly noisy, with sounds from the mother's body and external environment reaching the fetus.
Response to sound begins around 22-24 weeks, evidenced by changes in fetal movement.
Chenosensation (Smell and taste).
Fetuses demonstrate the ability to differentiate between sweet and noxious substances.
Newborns show a clear preference for their mother's scent.
Difficult to separate taste and smell in the womb due to amniotic fluid.
Foundations: All the senses adults possess operate to some extent in the fetus, though at a less developed level.
Somatosensory development and the question of pain.
Touch development.
Receptors spread throughout the body over the following weeks.
Sensory neurons develop and connect to the spinal cord and brain.
Initial touch receptors form around the face and lips by 8 weeks.
Foetal movement provides crucial stimulation for the somatosensory system.
Pain.
Foetus might experience noxious stimuli, but likely not complex, conscious pain.
Potential for response but not necessarily the full experience of pain.
Basic neural structures for pain response begin forming in the first trimester.
Development of the pain system.
Basic structures.
This includes:
Spinal cord connections: Signals from nociceptors are transmitted to the spinal cord.
Ascending pathways: Nerve fibbers relay signals upwards towards the thalamus.
Nociceptors: Specialised nerve endings to detect harmful stimuli.
Essential components for a primitive pain response form early in the first trimester.
Immature brain.
Higher brain areas involved in the complex experience of pain are underdeveloped in the foetus. This makes the conscious experience of pain, as understood in adults, unlikely.
Potential for response vs. conscious pain.
Reflexive reactions: Fetuses may exhibit responses to noxious stimuli. These include:
Increases in stress hormone levels.
Withdrawl movements.
Changes in heart rate and blood pressure.
Uncertainty of feeling: Whether these reactions translate to the same conscious, complex pain experience as an adult is debated. Here's why:
Cortical immaturity: The cerebral cortex, crucial for complex thinking and feeling, isn't fully developed.
Lack of prior experience: Pain perception is partly shaped by previous experiences which the fetus lacks.
Ethical implications.
Pain management: There's debate and research into whether foetal pain management should be used in situations.
Balancing concerns: It's a complex area balancing the potential for foetal discomfort with the importance of providing medical care.
Medical procedures: The potential for foetal pain raises ethical concerns about procedures performed.
Temperature.
Initial reliance on caregivers: Newborns depend entirely on caregivers to provide a warm environment.
Gradual development: A baby's temperature regulation systems gradually mature. They start to shiver and sweat, developing better control over their internal temperature.
Vulnerability to extremes: Why it's crucial to keep newborns warm and avoid extreme temperatures.
Immature systems: Newborns lack the developed mechanisms for maintaining body temperature. Here's why:
Underdeveloped sweat glands: They can't cool down effectively by sweating.
Limited body fat: Newborns have less insulating brown fat than adults.
High surface area to volume ratio: Babies have a lot of skin in proportion to their body mass, making them lose heat quickly.
Touch: The first sense.
Initial focus: Touch receptors form first around the mouth and lips, areas vital for a newborn's survival.
Expanding development: over the following weeks, touch receptors spread in a predictable pattern.
Pioneering sense: Touch is the earliest sense to develop in the womb, beginning around 8 weeks of gestation.
Prenatal vision development.
Structural development.
Key structures of the eye, like the lens and retina, form throughout the 1st trimester.
The retina, containing light-sensitive cells, continues to mature throughout pregnancy.
Limited perception.
A newborn's vision is blurry and not fully developed.
However, the prenatal experience of light exposure might play a role.
Early light detection.
It isn't full vision, but the foetus can likely perceive light-dark changes.
Around week 16 to 20 of pregnancy, the developing eyes become sensitive to light.
Foetal learning.
Exposure learning.
Preferences develop based on repeated exposure.
Mother's voice.
Prominent sound for the foetus, both internally and externally.
Newborns show a preference for their mother's voice, facilitating bonding.
Possible exposure to language patterns in the womb.
Habituation.
Repeated stimuli lead to decrease responses.
Shows the foetus's ability to form simple memories.
Music.
Foetuses perceive melodies and rhythms.
May have temporary calming effects.
Develop preferences for familiar melodies heard prenatally.
Active learners: Foetuses are capable of basic learning that lays the groundwork for the future.