Introduction to Development and Ageing Flashcards
What are the trends of development and ageing?
More older population so burden of disease increase
Why do you study development?
- understanding birth defects
- understanding cancer
How common are birth defects and what are they caused by?
- 2-5% births have a recognisable birth defect
- 70-75% of unknown cause
- Responsible for up to 70% of neonatal deaths (before 1 month) in 1995
- Responsible for 22% of infant deaths (up to 15 months) in 1995
What is the trend with increasing maternal age and birth defects?
- Age at which families are being started is increasing
- This is at odds with increased sub fertility/birth defects
What are the normal processes of developmental biology?
- proliferation
- apoptosis
- migration
- responsiveness to local signals and neighbouring cells
- unrestrained developmental processes underpin the pathophysiology of cancer
What is the Brenner hypothesis?
- Could variations/disruptions in development underpin common/chronic diseases
- Could nephron number determine risk of hypertension in later life?
- Opportunities of tissue repair?
What is the Barker hypothesis?
- Impact of the uterine environment ‘programmes’ the fetus for postnatal life
- Low birth weight or premature birth associated with risk of cardiovascular disease in adulthood
- Evidence for link to hypertension, T2D and others
What are potential stressors for fetal origins of adult disease?
- Endocrine (cortisol)
- Nutritional
- Extrinsic toxicants (e.g. smoking)
What is epigenetic modification?
- heritable changes to the DNA which do not alter the sequence of bases.
- Stressors are not altering sequence of ACTGs but chemical changes of how DNA interpreted, how genes switched on and off can be altered
What do you chart for child development?
- Gross motor control
- Fine motor control
- Cognitive development
- Language development
- Social and emotional development
Where does fertilisation happen?
-Occurs within the fallopian tube
What does fertilisation trigger?
cortical reaction
What happens in the cortical reaction?
- Cortical granules release molecules which degrade Zona Pellucida (e.g. ZP2 and 3)
- Therefore prevents further sperm binding as no receptors
- Haploid to diploid
What are the stages in the development of conceptus?
- Continues to divide as it moves down Fallopian tube to uterus (3-4 days)
- Receives nutrients from uterine secretions
- This free-living phase can last for ~ 9-10 days
What is the attachment phase in implantation?
outer trophoblast cells contact uterine surface epithelium
