Metabolism and growth Flashcards
Growth
Implies development from the time of birth/ conception(?) to the time of maturity.
Generally implies increase in size resulting from cell multiplication and cell expansion, as well as maturation of tissues.
Obesity
Excess body fat has accumulated to the extent that it may have a negative effect on health.
Malnutrition
Results from eating a diet in which one or more nutrients are either not enough or too much such that the diet causes health problems.
Malnutrition often refers to undernutrition, however can refer to overnutrition
When does prenatal growth occur?
From conception to birth
What hormones are important for foetal growth?
Insulin, insulin like growth factors (IGF-1), and GH/ placental GH to a lesser extent.
What is the most important factor that drives foetal growth?
Substrate delivery from the mother is the most important factor
What is post-natal growth?
From birth to adulthood.
How much does mass increase in post-natal growth?
20 fold
Major determinants of post natal growth are…
Major determinants include hormones (GH, action via IGF1/2, thyroid hormones, sex steroids), genetic (parents height), socio-economic factors, chronic disease and psychological factors.
Why are infants of diabetic mothers at risk?
Maternal hyperglycaemia leads to foetal hyperinsulinemia (as leads to stimulation of IGF-1 production and deposition of adipose tissue). Therefore foetus has increased fat deposits, length and lean body mass.
What is the cause of leprechaunism?
Insulin receptor failure - leads to severe dwarfism.
What does pancreatic agenesis have on infant?
Neonatal diabetes - average 50% reduction in body weight
What is Beckwith-Wiedemann syndrome?
Excessive IGF2 production and somatic overgrowth
What can issues in foetal growth lead to?
Leads ti abnormal physiological responses and predisposing to later diseases. Possible related to altered hormonal sensitivity resulting in resetting of homeostatic circuits to a different level.
IGF1 role?
Growth following birth
IGF2 role?
Gestational growth
Insulin role
Insertion of GLUT4 into cells for glucose uptake
GH role
Variety of actions
Increase IGF secretion from liver
Increase protein synthesis
Decrease glucose uptake into adipose and increase lipolysis
Decrease of glucose uptake into muscle and increase amino acid uptake
Human placental lactogen role
Modifies the metabolic state of the mother during pregnancy to facilitate the energy supply of the foetus.
Decreases maternal insulin sensitivity to increase maternal blood glucose.
Decreases maternal glucose utilisation, and increases lipolysis to free fatty acids for availability to the mother, so that relatively more glucose can be utilised by the foetus.
What releases HPL?
Placenta