Describe how low blood water levels are controlled in the human body. (5 marks)

Changes in blood water levels are detected by the hypothalamus through the negative feedback mechanism in homeostasis (2 marks). The pituitary gland releases anti-diuretic hormone into the bloodstream as a result (1 mark) and binds to the receptors on the cells of the collecting duct (of the nephron) (1 mark). The collecting duct becomes more permeable (1 mark) and water moves out of the collecting duct and into the blood by osmosis (1 mark).
N.B. Do not accept answer for high blood water levelsWords in brackets not required.