Renal System By: Dr Safa Abdul Ghani Kidney Functions : Overview • Excretion : Metabolic Wastes & Foreign Molecules Include urea, uric acid, creatinine, end product of hemoglobin metabolism and metabolites of hormones • Homeostatic Regulation : Regulate the volume and composition of the extracellular fluid • Control pH • Control blood volume & blood pressure • Controls osmolarity • Controls ion balance • Regulating Hormones & Enzymes • stimulating the production of red blood cells (Erythropoietin) • Activation of vit D Excretory System: Anatomy Review Figure 19 - 1: Anatomy Summary: The Urinary System Figure 19 - 1a Figure 19 - 1c The functional unit of the kidney is the nephron Which is located in both the cortex and medullary areas (1.2 Million) Kidney Cortex Medulla Pelvis Nephrons Nephron • The nephron consists of: • Vascular components • Afferent & efferent arterioles • Glomerulus • Peritubular capillaries • Vasa recta • Tubular components • Proximal convoluted tubule • Distal convoluted tubule • Nephron loop (loop of Henle) • Collecting duct • Tubovascular component • Juxtaglomerular appartus Figure 19 - 1j Nephron • The nephron consists of: • Vascular components • Afferent & efferent arterioles • Glomerulus • Peritubular capillaries • Vasa recta • Tubular components • Proximal convoluted tubule • Distal convoluted tubule • Nephron loop (loop of Henle) • Collecting duct • Tubovascular component • Juxtaglomerular appartus Circulation Figure 19 - 1d – e Figure 19 - 1i Figure 19 - 1g Cortical nephrons Figure 19 - 1f Nephron Functions: urine formation • Filtration • Reabsorption • Secretion • excretion Figure 19 - 2 Figure 19 - 3