Ch 13 Urinary System PDF

Human Physiology 13. Urinary System 13. Urinary system 13.1 Contents urinarysystem eliminatewaste Anatomy...

Human Physiology 13. Urinary System 13. Urinary system 13.1 Contents urinarysystem eliminatewaste Anatomy Uvea Filtration, reabsorption and secretion area NH Balance of sodium and water Balance of calcium, phosphate and pH E.EE iiiinn bloodpressureregulation 13.2 Function Regulation of the amount of _water ____ _ _ions and _ _ _ _ _ _ _ in the body. _ _ _ _ _ _ _ _ _ _ _ _ of metabolic wastes. _ _ _ _ _ _ _P_ _excretion Removal Production of _hormones _ _ _ _ _ _ _ and enzymes. 13.3 Structure of the urinary system _ _ _ _ _ _ : filter blood to produce urine. _Kidneys _ _ _ _ _ _ _ : transport urine from kidneys to bladder. ureters _ _ _ _ _ _ : store urine until voided from body. _Bladder _ _ _ _ _ _ _ : carry urine from bladder to the outside of the body. Urethra 13.4 Kidneys Renal _ _ _ _ _ _ – nephrons and blood vessels. cortex Renal medulla ________ Renal pyramids _ _ _ _ _ _ _ _ – parts of nephrons. fin't Renal columns _ _ _ _ _ _ _ – blood vessels. Sodium gradient growing from _ _ _ _to _tortex _ _medulla ___________ Nat medulla Renal _pelvis _ _ _ _ _ - collects urine into ureter. _ _ _ _ _ _ _ - filtering unit. Nephron 1 Human Physiology 13. Urinary System 13.4.1 Nephrons Over _1_million _ _ _ _ _ _ _ per kidney. They make the unit of blood filtration. Formed by: Renal _torputtle _________ mesandial _ _ _ _ _ _ _ _ _ = ball of capillaries + mesangial cells (smooth muscle). _glomerulus _ _ _ _ _ _ _ _ arteriole. atterent _ _ _ _ _ _ _ arteriole. _efferent _ _ _ _ _ _ _ _ _ (Bowman’s) capsule = renal tubule forming a cup around the _glomerular glomerulus. Fluid is filtered by _ _ _ _ _ from glomerulus into glomerular capsule, pass _ _size through the endothelial cells, _basement _ _ _ _ _ _ _ membrane and the foot processes of _podocytes _________ Renal _ _____ tubule _ _ _ _ _ _ _ convoluted tubule – in the cortex. _proximal Loop of _ _ _ _ _ – extends into the medulla and loops back. Henle _ _ _ _ _ convoluted tubule – in the cortex. _Distal __ _ _ _ _ _ _ _ _ duct – crosses medulla to drain into renal pelvis. collecting ma Fifa late ii.it E f medulla i kin Iiiiii 2 Human Physiology 13. Urinary System 13.4.2 Types of nephrons Suxtamedunary _ _ _ _ _ _ _ _ _ _ _ _ _ _ nephrons: Positionednext _ _ _ _ _ _ _ the medulla. to Have a _long _ _ _ loop of Henle. About 15% of all nephrons. _ _ _ _ _ _ _ nephrons: _tortilal _ _ _ _ _ _out Positioned _farther _ _ _ _ _ in the cortex Have a _short _ _ _ _ loop of Henle. Most nephrons. 13.4.3 Juxtaglomerular apparatus Found where the distal convoluted tubule touches _ glomerulus __________ The afferent arteriole wall has _juxta _ _ _ _ _ _ _ _ _ _ _ cells (pressure sensors). _ _ _ _glomerular _ _ _ _ _ _ muscle cells - secrete the hormone renin smooth _ _ _ _ _ (blood pressure and sodium). The wall of the distal convoluted tubule has: mania _ _ _ _ _ _ _ (NaCl sensors) _ _ _ _ _one Stimulate juxtaglomerular cells to release _ _____ renin Control the dilation or constriction of the _afferent _ _ _ _ _ _ _ arteriole. sensorytonat o Gunatrelentif.tt ntion 3  Human Physiology 13. Urinary System 13.4.4 Renal capillaries 2 sets of capillaries: _glomerular _ _ _ _ _ _ _ _ _ and _ _peritubular __________ __ _ _ _ _ _ _ _ _ capillaries - specialized for filtration. glomerular Fed and drained by _arterioles _ _ _ _ _ _ _ _ _ (afferent and efferent). Blood pressure in capillary forces blood fluids into the _ glomerular _ _ _ _ _ _ _ _ _capsule _________ _ _ Peri _ _ _t_ubular _ _ _ _ _ capillaries __________ to_ _ _vain _ _ _ _recta _ _ _ _ _ _ _ _ receive materials reabsorbed from the filtrate. pump 13.5 Glomerular filtration a _ _ _ _ _ ntic _Hydro _ _ _ _ _ pressure vs. 05Mt _ _ _ _ _ _ _ pressure. particle Pumping by the _ _ _ _ _ makes hydrostatic pressure higher in _lapillaries heart _ _ _ _ _ _ _ _ _ _ than in Bowman's capsule. Inflytial Since _ _ large _ _ _ _ _ _ _ _ stay in capillary, osmotic pressure would make water flow _ _ _ _ proteins from Bowman’s capsule to the capillary, but it is not strong enough to overcome the _ _ _ _ _ _ _ _ _ _ _ pressure. mail.tt Filtration is _ _ _ _ _ _ _ – particles aremoretuiagy.ie ak globerulu selected by _ _ _ _ _ retpiartYYe'sinblood release waste inpillaries titiitiitational iii glucose Bad loose energy 4111bn Infiltrate lapillaries and 4 squishparty Ad lYhe Rehlheffneeded podocyte tell in Bowman capsule  Human Physiology 13. Urinary System Glomeruli in the kidney filter (leak) more than other capillary beds. Her bed Filtration membrane is _very _ _ _ _ _ _ _ _ _ to water and solutes. _ _ _ _permeable Intamian Glomerular pressure is _ _ _ _ _ _ (_55 9h9 _ _ mm Hg) produce180 _ _ _ l/day vs. _ _ _ l/day formed by other capillary beds. Glomerular Filtration Rate (GFR) = _125 _ _ ml/min = 180 _ _ _ l/day. Control of GFR Mfetide _ _ _ _ _ _ _ _ _ _ _ _ _ vasoconstriction (or dilation) have opposite effects. _ _ _ _ _ _ _Efferent Atterent Atterent T EE iI g iii fiEi Her iii I Iiii'll Iiii i reablorbtion Differential handling in the kidney Filtration, _ _ _ _ _ _ _ _ _ _ _ _ _ and secretion might occur in different amounts. mood off retardation titration fqreti.in mora Ht secretion blood filtrate 5 Human Physiology 13. Urinary System 13.6 Tubular reabsorption Tubular reabsorption begins as soon as filtrate enters the renaltubule _____________ Particles are transported: iii Attiretransport Across the _apical _ _ _ _ _ membrane. Lots of secondary active transport Across the basolateral _ _ _ _ _ _ _ _ _ _ _ membrane. Lots of Na+/K+ pumps. 10Active transport If the _transport _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ of glucose is exceeded, maximummanate it appears in urine (_ _ _ _ _ _ _ _ patients). bllf.ieuiose whatshappening Nattell onapical 72 side Nat Tosmolauity osmosis in Elton'll thirstitionin ululose Sodium reabsorption Ift little not kt Na+ is the most _abundant _ _ _ _ _ _ _ cation in the filtrate. Na+ reabsorption is almost always done through _Altive _ _ _ _ _ transport. The active pumping of Na+ (via Na+/K+ ATPase) generates an _ _ _electromemical _ _ _ _ _ _ _ _ _ _ _ that is coupled to passive entrance of other substances _ _ _ _ _ _ _ _ _ _gradient (glucose, etc.) via co-transporters. so 13.7 Tubular secretion pettiatifollowingwat Ytiveransport Hydrogen ions, _potassium _ _ _ _ _ _ _ _ _ _ , and organic anions (urea) move from the peri_ _ _ _ _ _ _ _ _ _ _ capillaries into the tubular lumen. _ _ _ _tubular Tubular secretion is important for: 6 Human Physiology 13. Urinary System _ _ _ _ _ _ _ _ of drugs and drug metabolites. _Elimination _ _ _ _ _ _ _ _ _ _ of substances or end products that have been reabsorbed by passive processes (urea and uric acid). Removing excess _ _ _ whyYffed notlet Controlling blood _ _ _I 13.8 Renal clearance _ _ _ _ _ _of This is the _volume 1112 nowmumenditt.hr _ _ _ _ _ _ _ that is cleared of a substance in one minute _ _plasma (ml/min). NotGernowmuchwentthroughG RC=UV/P U = concentration of the substance in the urine _ _ _ _ _ (mg/ml). V = _flow _ _ _ _ _ _ of urine formation (ml/min). _ _ _rate P = concentration of substance in the plasma _ _ _ _ _ _ (mg/ml). HER RI ReablorbAll 2 Urine RFO If reabsorption is complete, RC =go _. Ex: glucose. jtiltuation IFR If both reabsorption and secretion = 0, RC = _ _ _ _ Ex: _ _ _ _ _ _ (fruits and vegetables) is ideal for measurement, but not produced by the inulin body. weatininete It is freely filtered and not reabsorbed or secreted. fi _ _ _ _ _ _ _ _ _ _ is produced by the body and used to estimate GFR. It is freely filtered but secreted in small amounts (estimate is an _ _ _ _ _ _ _ _ _ _ _ ). _ _approximation Produced in muscles from the metabolism of _trentine _ _ _ _ _ _phosphate ____________ 13.9 Micturition (_urination ________) _ _ _ _ = filtrate that is not reabsorbed. urine _ Drains to renal pelvis, ureters, urinary bladder and _ _ _ _ _ _ _ _ Urinary bladder stores urine until excreted by the mail.it nretieTractEiiiiititi ____________________ Micturition is initiated by a nervous reflex which causes the moon _ _ _ _ _ _ muscle of the bladder walls to contract and the _ _ _ _ _ _ _ _ _ _ to relax. 2 external t.SIff 13.9.1 Incontinence smooth taim mnturition.intfbhihter Involuntary _release _ _ _ _ _ _ of urine. _ _ _ _ _ _ incontinence (just leaks) Strell _ Triggered by sneezing, _loughing _ _ _ _ _ _ _ , exercise. More common in women _ _ _ _ _ , older than 60, due to weakening of urethral support. Eywomentell m to queene urethra 7 when it it tonsidered urine  origin.ie iateeieatiiiiaie a Human Physiology 13. Urinary System _ _ _ _ _ _ _ replacement is used to improve vaginal tonus _estrogen _ _ _ _ _ _ , or surgery to improve vaginal _support _ _ _ _ _ _ of the bladder and urethra. _ _ _ _ incontinence (desire to urinate). _urge Caused by bacterial ______________ intention Treated with drugs which relax the _ detrusor _ _ _ _ _ _ _ _ _ muscle. 6 smoothm 13.10 Blood pressure and osmosis _ _ _ _ are surrounded by extracellular fluid (interstitial fluid and plasma). _tell UM Extracellular fluid is mostly water and sodium _ _ _ _ _ _ is the main solute. _ _nothin t.tiieum.is _ _ _ _ _ _ _ _ of the water are inside cells, but almost all sodium is _ _ _ _ _ _ _ _ iiite Loss of extracellular fluid is _ _ _ _ _ _ _ _ _ _ _ _ _ than loss of water through sweating. If extracellular fluid is removedmorbidity (_ _ _ _ _ _ _ _ )vomit TYYYE.me Causes _ _ _ _ _ _ _ _ _ _ _ _ _. The body response is mostly based on the titulfaraemia Prune alliterone morecom hormone _ _ __________ NatIf water is removed (dehydration) NOTreleasing futility 1994 Causes increase in _ _ _ _ _ _ _ _ _ _ _ The body response is mostly based on the hormone _valthen in __. _ _ _ _ _ _ _ _antidiuretic hormone ADH in iii Iiiliiiiiiiiiiii.mm iiii Iiii.liiii II 13.10.1 Regulation of sodium Loss of sodium (urine, sweat) is tightly _ _ _ _ _ _ _ _ _ to keep body sodium constant. regulated Na+ excreted = Na+ _filtered _ _ _ _ _ _ _ – Na+ reabsorbed But the amount of sodium in diet is highly _variable ________ 8  Human Physiology 13. Urinary System mostansoration zoa through no osmosis H2o l agnaporial outinfiltrate aldosterone im ifeng.it 1ii iiiiii 300mosm iiioigjiiIi.it iiiiifIiiii iii7inmtr.ie Iiiii itiEiiii mmm.it neepera.am meamn tennis iiiis iim.tw IE iihiiiiii.it fiatpeivi V90omosm Nat gradient reassurn Hatpin iiiiE i men 2Kipites How is it monitored? onlynowtonsideredurine nImposition There are no sensory receptors for sodium in blood ______ affiliates Instead, receptors in the kidneys monitor the _ filtrate ________ secretehormone _ _ _ _ _ _ _ _ of the juxtaglomerular complex. _ _ _ _ Denia mania y reninEpithtionot Yeletptor In addition, blood pressure informs about extracellular water _ _ _ _ _ _ _ _ _ receptors in venous, atrial and arterial walls. _barometric Nat There are _NO _ _ control mechanisms: pressureDropping GFR ___ Drop of _wat _ _ produces drop of GFR: billaifampquostatist Eitan Drop in blood pressure Direct effect on GFR ___ Indirect: _ baroreleptors _ _ _ _ _ _ _ _ _ _ _ _ => sympathetic nerves => constriction of afferent arterioles => drop GFR Increase in Na+ increases _ _ _ _ IiiIEiiiiii Tannenattaniaitianat 9  Human Physiology 13. Urinary System Na+ reabsorption Signals: Detetta taillot _ _ _ _ _ _ _ – paracrine signal – juxtaglomerular complex. _ _ _ _ _ densa macula Neighborsen 1544597 _ _ _ _ _ _ _ _ _ _ _ _ _ cells are themselves intrarenal baroreceptors. fe.rsOther _ baro _ _suxtaglomerular AFYE ____ _ _ _ _ _ _ _ _ – CNS -> sympathetic stimulation of receptors juxtaglomerular cells. BP Juxtaglomerular complex secretes enzyme renin ______ 99th Renin breaks down _angiotensinogen _ _ _ _ _ _ _ _ _ _ _ _ _ _ produced by liver. _ _ _ _ _ _ _I_ _ _ _ Forms the product _ _angiotensin f Converted into angiotensin _ _ by enzyme in _ _ _ _ _ _ _ _ _ _ cells of capillaries. _endothelial Angiotensin II stimulates: in iiiiia.gg _ _ _mmonarictionn _____________ suprarenal to secrete _ _aldosterone _________ E ReablorbmoreNat titiatiitiinat Tata whatissecretion Effects of the _ _ _ _ _ _ _ aldosterone hormone Aldosterone _ _ _ _ _ _ _ _ _ _ _ of Na+ in DCT and cortical collecting ducts. _ Reabsorption Olfaction _ _ _ % of filtered Na+ is excreted, depending on aldosterone. 0 2 10  10059 artine thhhtn Human Physiology 13. Urinary System Stimulates synthesis of _channels _ _ _ _ _ _ _ _ _ _ for reabsorption. _ _ _ _ _ _t_ pumps Promotes reabsorption of Na+ also in _ _large _ _ _ _ _ _ _ _ _ , sweat _ _ _ _intestine and salivary glands. Natinsweat B _atrial _ _ _ _ _ _ _ _ _ _ _ peptide _ _ _ _ _ _natriuratis Secreted by cells of the cardiac _atria B.P swell of the _ _ _ _ if pressure too high, causing distension muscle. _ _ _ _ _ _ _ Na+ reabsorption in the renal tubules. inhibit _ Inhibits _ aldosterone _ _ _ _ _ _ _ _ _ _ secretion. Increases GFR through renal _ _unlodilation ___________ If itp B.P 13.10.2 Regulation of water H2O Popsifitary Control of water without affecting _Not ____ H2o response flain Triggered by osmoreceptors in the _ hypothalamus ____________ _ _ _ _ _ _ _ _ _ _ _ _ _ _ secretes ADH (antidiuretic hormone, vasopressin) _Neuronypophatis ADH increases the permeability of the 1 1 13.1 _ _ _ _medullary _ _ _ _ _ _dust _ _ _ _ _colletting __________ to water and it also 2 produces _ _unto _ _ lonitristion _____________ Ifmosil Large losses also activate _ _paroreleptors _ _ _ _ _ _ _ _ _ _ _ which stimulate the secretion of Renin _ _____ 2 tomplex 13H20extratenmar The center of54 9 fmerular _ _ _ _ _ _ in the hypothalamus stimulates the behavior of _drinking _______ EYE nlaima water. ADH is also secreted in response to _anaststress ________________ Relodetion hypertension _ _ _ _ _ _ _ _ _ _ _ _ involves an increase in vasopressin levels. _ _ _ _ _ _ inhibits the secretion of vasopressin → _urinate _ethanol _ _ _ _ _more _______ in anttansorbing Llost Initianori 1 4f ofH2oTreablubtion1120 aquaporins 7 11 Human Physiology 13. Urinary System 13.10.3 Regulation of pH _ane _ _ _ _ _ _ secrete H+ into the lumen of the nephron and _ _ _ _ _ _ into the interstitial fluids. y my mony iumehniot.in niidwiaia iii itiiiiQIniiiiii tell 12