GLOSSARY

Renin is a renal secreted enzyme initiating angiotensinogen processing.

Renin–angiotensin–aldosterone, vasopressin and natriuretic peptides regulate volume, sodium and water through distinct actions. Vasopressin prominently regulates water excretion, while aldosterone affects sodium and potassium handling. Sweating, fluid intake and environment alter these signals. Their activation alone cannot specify an exact drinking or salt prescription; actual balance and individual conditions matter, and hormonal water retention should not be mistaken for proof that excessive drinking is harmless.

Hormones are chemical signals whose effects depend on target cells and appropriate receptors. Endocrine generally describes communication through blood, while local and neural signals also contribute. One substance can have several roles and sources. Calling something a metabolic or appetite hormone does not imply an exclusive effect; interpretation requires the signaling network, food and activity rather than assigning the body's response to one molecule alone.

Synthesis, storage, secretion, transport and clearance are distinct processes. Blood concentration reflects entry and removal rather than directly measuring secretion; exercise-related plasma-volume changes can also affect it. Half-life depends on hormone form and method and is not identical to the duration of all effects. Comparisons therefore need sampling time, previous food and recent activity standardized or recorded rather than interpreting isolated concentration differences without context.