Week 4

Question 1

4 phases of growth

Answer 1

1. Intrauterine
2. Infancy
   - driven by nutritional factors
3. Early childhood
   - dependent on GH
4. Pubertal
   - regulated by GH and sex hormones

Question 2

2 Apoptosis pathways

Answer 2

1. Intrinsic - BAX
2. Extrinsic - FAS

Question 3

FAS apoptosis pathway

Answer 3

FAS ligands (type of TNF) bind to death receptors.
Activates caspase 8 enzyme.
Activates caspases 3 & 7 which induce chromatin and cell breakdown.

Extrinsic pathway

Question 4

BAX apoptosis pathway

Answer 4

Caspase 8 activates BAX channel protein which inserts itself in mitochondrial membrane.
Cytochrome C release.
Other enzymes intiate apoptosis (such as Caspase 9).

Intrinsic pathway (Formation of Apoptosome)

Triggered by: DNA/mitochrondia damage, hypoxia, metabolic stress

Question 5

Stage of greatest fetal growth and weight gain

Answer 5

fetal growth greatest 16-20 weeks gestation.

fetal weight gain peaks at 34 weeks gestation.