Renal System Notes PDF

Renal System Functions of kidney: Remove waste products from the blood such as urea and creatinine Control the acid base balance (through HCO 3- & H+) Electrolyte homeostasis (K+, Na+ and Ca++) Secrete Hormones and enzyme like erythropoietin and rennin. CRF leads to anemia Activates Vitamin D. Regul...

Renal System Functions of kidney: Remove waste products from the blood such as urea and creatinine Control the acid base balance (through HCO 3- & H+) Electrolyte homeostasis (K+, Na+ and Ca++) Secrete Hormones and enzyme like erythropoietin and rennin. CRF leads to anemia Activates Vitamin D. Regulate body fluids and arterial blood pressure Make G from non CHO sources (make sugar from proteins at time of starvation (gluconeogenesis). )  Urinary System Two kidneys Two ureters Urethra  Anatomy of Kidney Renal cortex: outer 1 cm… cortical atrophy means damage to the kidney…in the cortex most of the glomeruli reside Renal medulla: different types of tubules… give striated appearance (‫)مخطط‬ Lobe of Kidney Nephron Tubular Segments 12  Basic Mechanisms of Urine Formation 13 Date: / Date: / Date: / Filtration Pressure Date: / Determinants of Glomerular Filtration Rate 1  Renal Handling of Different Substances 4 Date: /  Normal Renal Tubular Na+ Reabsorption (16,614 mEq/day) 7% 65 % (1789 mEq/d) 25,560 mEq/d 25 % (6390 2.4% mEq/d) (617 mEq/d) 0.6 % (150 mEq/d)  Basic Mechanisms of Urine Formation 3  Mechanisms of secondary active transport. Date: / Glucose Transport Maximum Sodium Homeostasis Sodium is an electrolyte of major importance in the human body. It is necessary for : 1.normal extracellular volume dynamics 2. excitability of certain tissues…you probably remember action potential: depolarization and c onduction 3.cotransport and countertransport. With glucose, a.a, H+ 4.countercurrent mechanism... concentration and dilution of urine 5.Sodium accounts for a significant portion of plasma osmolarity. The latter can be estimated by multiplying plasma sodium concentration times 2.1. 6. H+ secretion (acid – base balance) and K+ secretion occur as countertransport with Na+. Most of the primary active transport in the entire tubular system is to transport Na+ Date: / Date: /  The Counter Current Mechanism Compare to the Nephron and recall parts ? ? ? ? Date: /  Development of Isosthenuria With Nephron Loss in Chronic Renal Failure (inability to concentrate or dilute the urine)) 1200 Maximum urine osmolarity Osmolarity 600 (mOsm / L) 300 Plasma Osmolarity 0 Minimum urine osmolarity 100 75 50 25 0 Nephrons (% normal) Concentration of Different Substances in Tubular System compared to Plasma Concentration If water is reabsorbed to a greater extent than the solute, the solute will become more concentrated in the tubule (e.g., creatinine). if water is reabsorbed to a lesser extent than the solute, the solute will become less concentrated in the tubule (e.g., glucose, amino acids). Concentration and Dilution of the Urine Maximal urine concentration = 1200 - 1400 mOsm / L (specific gravity ~ 1.030) Minimal urine concentration = 30-50 mOsm / L (specific gravity ~ 1.003) Date: /