Kidney Functions • Regulation of body fluid osmolality & volume: Excretion of water and
NaCl is regulated in conjunction with cardiovascular, endocrine, & central nervous systems •
Regulation of electrolyte balance: • Daily intake of inorganic ions (Na+, K+, Cl-, HCO3-,
H+, Ca2+, Mg+ & PO43-) • Should be matched by daily excretion through kidneys. •
Regulation of acid-base balance: Kidneys work in concert with lungs to regulate the pH in a
narrow limits of buffers within body fluids. Excretion of metabolic products & foreign
substances: - Urea from amino acid metabolism - Uric acid from nucleic acids - Creatinine
from muscles - End products of hemoglobin metabolism - Hormone metabolites - Foreign
substances(e.g., Drugs, pesticides, & other chemicals ingested in the food) Production and
secretion of hormones: - Renin -activates the renin-angiotensin-aldosterone system, thus
regulating blood pressure & Na+,K+ balance - Prostaglandins/kinins - bradykinin =
vasoactive, leading to modulation of renal blood flow & along with angiotensin II affect the
systemic blood flow - Erythropoietin -stimulates red blood cell formation by bone marrow
