Functions of kidneys Primary function of kidneys: (1) Regulation of the volume and composition of extracellular fluid(ECF) (2) Elimination of waste products (3) Acid-base balance regulation (4) Blood pressure control(RAAS, ANP, renal PGs) (5) Synthesis of prostaglandins(systematic effect in lowering blood pressure) (6) Erythropoietin production for stimulating RBC production in bone marrow (7) Vitamin D activation(1 st step in the liver, 2 nd step in the kidneys) calcium absorption from the gastrointestinal tract (8) Ca 2+ and PO 4 2- regulation: by Parathyroid hormone[PTH] absorption of Ca 2+, PO 4 2- (bone metabolism) (Lewis et al., 2014) p. 1047 읽을 부분 : 성인간호학 ( 상권 ) 수분과 전해질, 수문사, 187-234 7
Functions of kidneys: Urine formation in Nephrons Glomerular filtration( 사구체 여과 ) Normal Glomerular Filtration Rate(GFR)= 125-130mL/min Inulin( 이눌린 ): 세뇨관벽에서 재흡수, 재분비 없이 요로 배설 Tubular reabsorption( 세뇨관 재흡수 ) Tubular secretion( 세뇨관 분비 ) 8 Lewis et al.(2014, p. 1048)
Blood supply to the kidneys 심박출량의 20-25% 이 신장으로 들어와 처리됨 신장 혈류량 : 1,500-1,800L/day 사구체 여과 : 150-180L/day 125mL/min[GFR] X 60mins X 24 hours = 180L/day 소변량 : 1-2L/day 신장 혈류량 : 소변량 = 1000 : 1 Functions of kidneys: Urine formation in Nephrons 9
Functions of kidneys Blood control: Renin-Angiotensin-Aldosterone System 11
Functions of kidneys : Blood control - ANP Atrial natriuretic peptide(ANP): In response to atrial distention(a result of an increase in plasma volume), ANP acts on the kidneys to increase sodium excretion Inhibits renin, ADH, and the action of angiotensin II on the adrenal glands suppressing aldosterone secretion a large volume of dilute urine relaxation of the afferent arteriole increasing GFR 12
Functions of kidneys : Blood control & Synthesis of PGs Renal prostaglandins(PGs): PG synthesis primarily in the medulla PGs have a vasodilating action increasing renal blood flow promoting Na+ excretion systematic effect in lowering blood pressure by decreasing systemic vascular resistance 13
References 14 김금순 외 (2012). 성인간호학 II, 7 판. 수문사 Monahan, Frances D (2007). Phipps' Medical-Surgical Nursing: Health and Illness Perspectives, 8th Edition. C.V. Elsevier Inc. Lewis, Sharon L.; Dirksen, Shannon Ruff; Heitkemper, Margaret M.; Bucher, Linda (2014). Medical-Surgical Nursing: Assessment and Management of Clinical Problems, Single Volume. Elsevier Health Sciences. Kindle Edition.