The importance of the thick ascending limb of Henle’s loop in renal physiology and pathophysiology

homeostasis, and water reabsorption, the latter through its contribution in the generation of the cortico-medullar osmotic gradient. The role of this nephron site in acid-base balance, via bicarbonate reabsorption and acid secretion, is sometimes misunderstood by clinicians. This review describes in detail these functions, reporting in addition to the well-known molecular mechanisms, some novel findings from the current literature; moreover, the pathophysiology and the clinical relevance of primary or acquired conditions caused by TAL dysfunction are discussed. Knowing the physiology of the TAL is fundamental for clinicians, for a better understanding and management of rare and common conditions, such as tubulopathies, hypertension, and loop diuretics abuse.