Week 8: Growth and Development - Life Stages Flashcards
What are the 3 major stages in foetal development?
Germinal - first 2 weeks
Embyronic - 3-8 weeks
foetal-9-38 weeks
Outline the germinal period
0-2 weeks
- Fertilisation of the zygote
- Pre-embryonic period where implantation occurs
- Formation of connectivity between maternal and embryonic circulation
Outline Embyronic Period
Week 3-8
- All vital organs and muscles will develop during this time
- Head and tail regions fold under
- First reflexes can be detected at the 8 week mark
Organogenesis - the differentiation of germ layers to form organs
Outline the Foetal period
Weeks 9-38(or 40)
All organ systems grow and become more mature
What is the Foramen Ovale?
It is the hole between the left and right atria that allow blood to bypass the lungs (as the fetus isnt breathing its own air) –> allows blood to be pumped around the foetal body
Implications may occur post birth where this hole doesnt close properly which is a serious condition raising the risk of stroke
What is a teratogen?
An agent that can induce or increase the incidence of congential malformations or physical defects
For example:
-Drugs
- Radiation
- Viruses
- Maternal Nutrition
Aspects that can influence childhood body composition
Body composition at birth (e.g. maternal nutrition, maternal pre-eclampsia or diabetes, smoking, interauterine growth restriction
Adiposity in infancy - high at birth is associated with increased risk of childhood & adult obesity
Birthweight
- Low birth weight is associated with increased risk of hypertension, CVD
What is the Barker Hypothesis?
Advocates that the origins of chronic diseases of adult life lie in fetal responses to the intrauterine environment
Study showed lower birthweight increased risk of type 2 diabetes, CVD and hypertension
Small babies may need extra attention to mitigate these risk during the development phase
What effect does exercise have on the embyro/foetus both preconception and post conception
Preconception - PA can promote increase sperm count
Post conception - Reduce risk of macrosomia & Foetal metabolic dysfunction
Define:
1. Growth
2. Maturation
3. Development
Growth
- Increase in size of whole, or specific body parts
Maturation
- The Tempo and timing of progress towards a mature biological state (e.g. puberty)
Development
- a process leading to changes in how a system is organised (differentiated and integrated)
See Part 1-Slide 19 of week 8 lecture for table
Chronological VS Biological Age
Chronological: Time duration since birth
Biological: ageing occurs as the body gradually accumulate damage to various cells and tissues
–> how old you body is physically (e.g. heart age)
Poor Lifestyle behaviours can accelerate the biological age –> increase risk factors for chronic diseases (e.g. diabetes)
What is Scammon’s curves?
Describes the differential and orderly course of timing of postnatal systemic growth
–> inidcate relative size attained in several body systems expressed as a percentage of adult size
THESE ARE NOT GROWTH CHARTS
What is a velocity curve? What does it indicate?
Compares the age in years to the weight&height gain of the child.
–> indicates how quickly a child may be gaining weight or height
The age at which a child reaches their peak height velocity –> relates to puberty development
–> this can impact outcomes such as pre adult height and weight
What causes skeletal maturation?
Closure of the epiphyseal (growth) plates
Trend of Bone composition against age?
There is a increased Bone mineral density with increasing age
–> creating a stronger bone is important as BMD begins to decrease during adulthood
