What are examples of conditions within cells that are regulated by the process of homeostasis?

Renal function is a prime example of a process regulated by homeostasis. For example, if you blood pressure drops you will activate a system within your body called the 'Renin-Angiotensin System'. Your Liver will release Angiotensinogen that will be cleaved to Angiotensin I by a hormone known as Renin, which is released from the kidney when your blood pressure drops below normal. Angiotensin I is then activated to Angiotensin II by the ACE enzyme that is present within the Lungs. Once this conversion occurs, Angiotensin II stimulates the Hypothalamus within the brain to release Vasopressin from the Posterior Pituitary gland. Vasopressin works on the collecting duct of the kidneys to increase water reabsorption in order to increase blood volume which in turn will increase blood pressure. Angiotensin II also stimulates the Adrenal Cortex to release another hormone known as Aldosterone, which functions in the kidney to stimulate Sodium reabsorption, Potassium excretion and also H2O re absorption. By stimulating the re- absorption of Sodium and Water, the blood pressure will be normalized back to normal