Blood

Pancreatic Islets of Langerhans maintain blood glucose level

Hyperglycaemia - too much blood glucose

Hypoglycaemia - too little blood glucose

Gluconeogenesis occurs in times of starvation (glucose production from lipid/protein sources)

Ultrafiltration: blood filtered under pressure > produces a filtrate identical to tissue fluid

Selective reabsorption: reabsorption of useful substances back into blood stream

Loop of Henle: reabsorbs water

Osmoreceptors in the hypothalamus: monitor osmotic blood concentration

Baroreceptors in the circulatory system: monitor blood pressure