课件：第三章水钠代谢钾代谢紊乱金惠铭.ppt

第三章 水、电解质代谢紊乱,第一节 水、钠代谢紊乱,Water and Na+ metabolism disturbance,一、正常水钠代谢,细胞外液,细胞内液,体液的容量Total body fluid volume Total body fluid volume and distribution,（一）体液的容量和分布）,ECF,ICF,2. 体液的分布 Distribution of body fluid,（二）体液的电解质成分,细 15% Na+ Cl- HCO3 - 外 胞 Tr,血 5% 液,第三间隙液,40% K+ HPO42-,Transcellular fluid,Electrolyte composition of body fluid,阳离子：Cation,阴离子：Anion,Selectively permeable memebrane,more water,less water,less solute,more solute,Hypertonic solution,Hypotonic solution,Osmotic pressure,高渗溶液,低渗溶液,(Osmolarity),（三）溶液的渗透压,1.取决于溶质的分子或离子的数目,2.体液起渗透作用的主要是电解质,3.正常血浆渗透压：280-310mmol/L,等渗、低渗、高渗,（四）水、电解质的生理功能和水、钠平衡,Water balance,Excitability,（五）体液容量及渗透压的调节,晶体渗透压 血容量 血管紧张素,渴觉中枢兴奋,渴感消失,在神经内分泌系统的调节下维持平衡,1. 渴感的调节作用,Regulation of body fluid and osmotic pressure,Nervous-endocrine system,Regulation of thirst,Thirst center,Crystal osmotic pressure,Angiotensin II,下丘脑 神经垂体,细胞外液渗透压增高,血管紧张素II增加,疼痛、情绪紧张,渗透压感受器,容量感受器,血容量增加,动脉血压升高,颈动脉窦压力 感受器,ADH,肾小管,H2O,+,+,+,-,-,-,细胞外液渗透压,2. 抗利尿激素的调节作用,-,Antidiuretic hormone,ADH,Renal tubule,Hypothalamus,Neurohypophysis,Carotid sinus,肾近球细胞,循环血量减少,肾动脉压下降 致密斑钠负荷减少 交感神经兴奋,肾素,血管紧张素II,血管收缩,肾上腺,醛固酮,肾小管,Na+ H2O重吸收,循环血量增加,+,血管紧张素I,ACE,-,3. 醛固酮的调节,Aldosterone,Renin,Juxtaglomerular apparatus,血容量血Na+ ,心房牵张感受器,ANP,肾素醛固酮,钠、水重吸收,限制ADH,利尿、利钠,4. 心房利钠肽的调节,5. 水通道蛋白,Atrial natriuretic peptide, ANP,Aquaporin, AQP,stretch receptor,Artriam,二、水钠代谢障碍分类,同时考虑、两种分法,（一）根据体液渗透压,Dehydration,Hypotonic dehydration,Isotonic,Hypertonic,Water,Intoxication,Edema,Salt,poisoning,Excess water,（二）根据血钠浓度及体液容量,Hyponatremia,Hypernatremia,Isonatremia,Hypovolemic,Hypervolemic,Isovolemic,渗透压对细胞的影响,Hypovolemic hyponatremia,Hypotonic dehydration,三、低钠血症,概念,Renal tubular acidosis,Renal parenchymal disease,Renal sodium loss,Extrarenal sodium loss,Body fluid excretion,尿、 氮质血症、 尿Na+,对机体的影响（Effects）,（2）,Azotemia,Shock,Polyuria,Low urine specific gravity,Apathetic,Drowsiness,swelling,肾外因素引起的低渗性脱水，尿钠少； 肾性低渗性脱水，尿钠多。,尿钠变化？,对机体的影响（Effects）,组织间液减少最明显,休克,Isotonic NaCl,高容量性低钠血症,Hypervolemic hyponatremia,(Osmolality),（二）,（体钠总量正常或增加),（低渗性体液）,（多见于急性肾功能衰竭, ADH ）,原因,Excessive water intake,Water excretion,嗜睡、躁动、 脑疝,对机体的影响（Effects）,Hemodilution,Water retention,Dysphoria,Hemotocrit,brain herniation,预防和治疗,等渗或高渗盐水,Hypertonic saline, mannitol, furosemide,Renal failure,Dialysis therapy,Primary disease,Isovolemic hyponatremia,原因和机制,等容性低钠血症主要见于ADH分泌异常综合征,Syndrome of inappropriate ADH secretion, SIADH,H2O,体液容量,轻度,尿钠排出,（ANP释放 + 近端小管吸收Na+ ),细胞外液渗透压,滞留水,IC,血容量N,ADH,Inside of cell,对机体的影响,等容性低钠血症防治原则,Convulsion,（四）高钠血症,Hypernatremia,（一）低容量性高钠血症,Hypovolemic hypernatremia,Characteristics,原因和机制,Psyche patient,Esophageal carcinoma,Coma,Oral pharyngeal region,原因和发病机制,口渴感正常，及时补水，不易发生,Hyperventilation(hysteria),Hyperthyroidism,Vomiting, diarrhea,对机体的影响,嗜睡、昏迷,血容量下降,Oliguria,Dehydration fever,对机体的影响,与低容量性低钠血症比较,Hypotonic dehydration,Pachyemia,（低容量性高钠血症）,（低容量性低钠血症）,防治原则,（二）高容量性高钠血症,Hypervolemic hypernatremia,特点: 血容量和血钠均升高,Latrogenic sodium retention,Aldosteronism,Primary sodium retention,Cushing syndrome,（三）等容性高钠血症,Isovolemic hypernatremia,特点：血钠升高 ，血容量无明显改变,Shreshold of osmoreceptor,1. 等渗性脱水,（五）正常血钠性水紊乱,（单纯性）,原因: 等渗液体大量丢失在短期内者，如呕吐、腹泻等,出汗,呼吸,高渗性脱水,低渗性脱水,水肿,二、水肿,（Edema）,2.,Conspectus,coelom,Anasarca,Local edema,Frank edema,Recessive edema,Pitting edema,Subcutaneous edema,（一）水肿的发病机制,The fluid interchange across the capilleries,Exchange imbalances in liquid: water and sodium retention,Effective hydrostatic pressure,Effective colloid osmotic pressure,Lymphatic return,血管内外液体交换平衡,1. 血管内外体液交换失平衡,水肿,（1）毛细血管流体静压增高,Right heart failure,Venous return blockade,Blood stagnation,Venous pressure,Effective filtration pressure,Formation of interstitial fluid,（2）,Plasma albumin,Synthesis disorder,Catabolism increases,（3）微血管通透性增加,各种 炎症,Transudation,Permeability,Inflammatory mediator,（4）,Filariasis,Tumor lymphatic metastasis,Radical resection of cancer,Lymphatic edema,Blockade of lymphatic return,Upper extremity,Filariasis,2.体内外液体交换平衡失调-钠、水潴留,球-管平衡,Glomerulotubular Balance,Reabsorption,Exudate excretion,Retention of sodium and water,（1）,不伴有肾小管重吸收相对减少,Filtration area,Effective circulating volume,2019/8/20,61,可编辑,心房钠尿肽,滤过分数,（,（2）,1）,Filtration fraction,FF,钠、水重吸收,有效循环 血量减少,钠水重 吸收,Afferent arteriole,Efferent arteriole,Non-protein filtrate,Proximal renal tubule,2）,分泌增加和灭活减少,体内外液体交换平衡失调-钠、水潴留,球-管平衡,球-管失衡,滤过率,滤过率,ANP,FF,重吸收 钠水,重吸收 钠水,滤过率N,ADH 醛固酮,Glomerulotubular imbalance,1. 水肿的性状,（二）水肿的特点,Specific gravity of urine,2.水肿的皮肤特点,3. 全身性水肿分布的特点,心性水肿、肾性水肿、肝性水肿,（三）水肿对机体的影响,炎性水肿：稀释毒物，运送物质，缓冲 （1）细胞营养障碍 （2）水肿对器官组织功能活动的影响,肺水肿、脑水肿、喉头水肿,第二节,Normal potassium homeostasis,1.,Bioelectrical activity,Osmolarity, osmotic pressure,Enzymatic activity,90%,2.,3. 钾平衡的调节,跨细胞膜转移调节 机体的钾平衡调节 肾脏的调节 （结肠出汗排钾）,Transfer regulation across the membrane,1钾的跨细胞转移调节,K+细胞内外移动的泵一漏机制,Pump-leak mechanisms,(1),Anabolism,Catecholamine,过量,Excess insulin,Catabolism,Sports,Beta-adre 阻滞剂,肾对钾的排泄是多吃多排，少吃少排、不吃也排,2.肾对钾排泄的调节,（90%）,（主要机制）,（自由通过）,(2),Chief cell,the lip cells,(3),Potassium excretion in colon,（一）低钾血症,低钾血症：血K+3.5mmol/L 缺钾：细胞内钾和机体总钾量缺失,多伴有缺钾,1.原因和机制,（1）钾摄入不足,厌食，昏迷， 消化道梗阻,（2）,剂,各种肾疾患,I/II型,Renal tubular acidosis,Diuretics of K efflux,Primary urine flow rate,Magnesium,经皮肤失钾,（3）, ,Glycogen synthesis,Barium poisoning,Acute alkalosis,Activity of beta-adrenergic receptor,Periodic paralysis,2. 低钾血症对机体的影响,（1）与膜电位异常相关的障碍,1）对神经-肌肉组织的影响,Resting membrane potential, Em,Neuromuscular tissue,Resting membrane potential, Em,Threshold potential, Et,急性低钾血症,细胞内液钾外流 Em负值,Flaccid paralysis,Muscle palsy,Anorexia,Abdominal distension,Paralytic ileus,Droopy,Lassitude,Drowsiness,Smooth muscle,Skeletal muscle,慢性低钾血症,Resting membrane potential,2）低钾对心肌的影响,心肌生理特性改变,心电图（ECG）改变,心肌功能损害,心肌的电生理特性,Electrophysiological features,Cardic action potential,Ion transfer,Cardiac myocyte,（Excitability）,Threshold stimulation,（Conduction）,Negative smaller,Speed,Amplitude,钠离子内流速度减慢,离子,Slow self-depolarization,自律细胞,（Rhythmicity）,Cation influxK+ efflux,Self-depolarization,Increase,（4）收缩性（Contraction）,轻度低钾血症 2期Ca2+内流加速 心肌收缩性,严重或慢性低钾血症 细胞内缺钾 心肌收缩性,Influx accelerates,Myocardial contractility,Severe or chronic hypokalemia,对心肌电生理的影响,A、兴奋性,B、传导性,C、自律性,D、收缩性,（三高一低）,低血钾症,U wave,心肌功能损害的具体表现,对洋地黄类强心药物毒性的敏感性增高,Premature beat,A-V block,Ventricular fibrillation,Sinus tachycardia,Ectopic pacemaker,Digoxin toxicity,cardiac reentry,Affinity,（2）与细胞代谢障碍有关的损害,1）骨骼肌损害 肌痉挛、坏死和溶解,2）肾脏损害 集合管上皮细胞肿胀、增生，尿浓缩 障碍导致多尿,（对其血流量有调节作用）,Skeletal muscle impairment,Urine concentration,Swelling, proliferation,Muscle spasm, necrosis and dissolution,（3）低钾血症对酸碱平衡的影响,Paradoxical acidic urine,Alkalosis,Acidic urine,3.,3.,Primary disease,血清钾浓度5.5mmolL,（二）高钾血症,极少伴有细胞内钾增多,1）钾摄入过多,2）钾排除减少,医源性,Itrogenic,Potassium-sparing diuretics,K,K,K,Acute acidosis,组织分解,组织分解,（2）,不