Renal Hormones and Enzymes in the Body

Renal Hormones and Enzymes

• Antidiuretic hormone (ADH) regulates urine volume by increasing water reabsorption and urine concentration in distal tubule and collecting ducts.

• Atrial natriuretic hormone (ANH) promotes sodium loss via the urine and is secreted by muscle fibers in the atrium of the heart.

Aldosterone Regulation

• Aldosterone is secreted by the adrenal cortex, increasing sodium absorption in distal collecting tubules and controlling potassium secretion.
• Increased serum potassium levels stimulate aldosterone secretion.
• Aldosterone secretion leads to increased sodium and water retention, and decreased renin formation.

Renin-Angiotensin System

• Renin is an enzyme secreted by the kidney, regulating sodium retention, blood pressure, and fluid volume.
• The renin-angiotensin system converts angiotensinogen to angiotensin 1 in the liver.
• Angiotensin II, formed in the lungs from angiotensin 1, is a vasoconstrictor that stimulates aldosterone production in the adrenal cortex.

Erythropoietin

• Erythropoietin is a hormone produced by the kidney in response to low oxygen levels in arterial blood.
• It stimulates increased red blood cell production in the bone marrow.

Nephron Structure

• The nephron consists of a proximal convoluted tubule and a peritubular region.