Quick questions on Nutritional and environmental diseases: HSC Biology Module 8

Approximately 1.3 million Australians have type 2 diabetes (T2DM); around 5 percent of adults. The number is rising with obesity rates.

Insulin normally binds receptors on muscle, liver and fat cells, triggering glucose uptake via GLUT4 transporters. In T2DM, intracellular fat metabolites and inflammatory signalling impair insulin receptor signalling, producing insulin resistance. Beta cells compensate by hypersecreting insulin; over years they exhaust, glucose rises, and diabetes appears.

Chronic hyperglycaemia non-enzymatically glycates proteins, damaging blood vessel walls.

Inhalation or ingestion of asbestos fibres (chrysotile, crocidolite, amosite). Less common: erionite (a similar fibrous mineral) and high-dose radiation.

Largely palliative. Pleurectomy and extrapleural pneumonectomy in selected patients. Chemotherapy with pemetrexed plus cisplatin.

Asbestos was progressively banned in Australia from 1989; total ban in 2003. Home renovators remain at risk; pre-1990 buildings should be tested before renovation.

Causes goitre and congenital cretinism. Reduced markedly in Australia by iodised salt and iodised baker's flour.

Causes neural tube defects in fetuses. Reduced by mandatory folate fortification of bread flour (Australia, 2009).

Causes rickets in children and osteomalacia in adults. Reappearing in heavily veiled or housebound populations.

Causes neurological damage in children. Reduced by removal of lead from petrol (1986 to 2002) and house paint.

PM2.5 from traffic and bushfires causes COPD and ischaemic heart disease. Black Summer (2019 to 2020) bushfire smoke caused approximately 400 excess deaths in eastern Australia.

Markers want specific mechanisms: smoking causes endothelial damage and oxidative stress; LDL promotes foam cell formation; hypertension shears the endothelium.

"Outline" = brief cause; "describe" = the mechanism in order; "compare" = the same features for two diseases side by side; "assess"/"evaluate" = a justified judgement, not a list.

Examiners reward a clear chain. State the cause (exposure or dietary imbalance), the mechanism (what goes wrong in the cells/vessels), then the effects (the clinical outcomes).

Quoting figures (around 1.3 million with T2DM, around 42 000 CVD deaths per year, around 700 to 800 mesothelioma cases per year) shows the epidemiological awareness NESA expects in this module.