The Kidney's Endocrine Function

Study Notes

Functions of the Excretory System (Urinary System Focus)

The kidney has multiple functions, including endocrine, metabolic, regulatory, and excretory functions.
The endocrine function of the kidney involves the production of erythropoietin, which stimulates red blood cell synthesis in response to low oxygen levels.
The kidney also produces renin, which is involved in regulating blood pressure.
The metabolic function of the kidney includes the activation of vitamin D and the synthesis of glucose from non-glucose precursors.
The kidney plays a regulatory role in maintaining fluid and electrolyte balance, including the balance of sodium, potassium, calcium, and magnesium.
The excretory function of the kidney involves the elimination of metabolic wastes, such as urea, uric acid, and creatinine, as well as the elimination of toxins.
Urine formation involves three major processes: glomerular filtration, tubular reabsorption, and tubular secretion.
Glomerular filtration occurs in the renal corpuscle and allows for the passage of water, small molecules, and certain medications into the filtrate.
Tubular reabsorption occurs in the proximal convoluted tubule and involves the active transport of glucose, amino acids, and ions back into the blood.
Tubular secretion occurs in the distal convoluted tubule and involves the removal of small molecules, H+ ions, and K+ ions from the blood into the filtrate.
Autonomic nervous system and the renin-angiotensin-aldosterone system play a role in regulating the glomerular filtration rate.
The reabsorption of water is controlled by antidiuretic hormone and occurs in the renal medulla.