Urinary system Designed by Pyeongsug Kim ©2010 Picture from Physiology - i

Kidney Function -Cleans the blood removes ____ and other nitrogen- containing wastes. -Balance the blood in concentration Filtration Reabsorption Secretion ions, nutrients, water content -pH balnce by secretion of ___ or _____ -Urine formation -Hormones Adrenal glands ~ adrenal medulla, adrenal cortex urea H+HCO 3  If need or decrease (reduce)  If excess  Almost everything except Protein & RBC Designed by Pyeongsug Kim, ©2010

NephronNephron -Functional unit of the kidney -Regulate…. Blood pressure Electrolyte concentration pH, [H+] -Remove waste A B A: B: Bowman’s capsule Glomerulus Bowman’s capsule encases _________. glomerulus Designed by Pyeongsug Kim, ©2010

_________: A substance enters the glomerular ultrafiltrate. Filtration _____________: A substance is transported from the filtrate, through tubular cells, and into the blood. Reabsorption _____________: A substance is transported from peritubular blood, through tubular cells, and into the filtrate. Secretion In the kidney Designed by Pyeongsug Kim, ©2010

Nephrons Bowman’s capsule -Encloses a __________. -Filters the smaller blood molecules into the _________ ________= The selective passage of molecules - Powered by _____________ -Form the renal corpuscle (the filter) ______= The liquid that passes from the blood into the nephron. :water, ions, nutrients (glucose, amino acids, and vitamins), nitrogen-containing wastes (Urea) glomerulus nephron Filtrate Filtration blood pressure Blood cells and blood proteins are too large to enter the nephron. _________ Filter -Filter the blood, Reabsorb -Reabsorb solutes and water for balance. except waste(Urea) and excess water/solutes. Form -Form the urine. Designed by Pyeongsug Kim, ©2010

a: b: c: A: B: C: D: E: Adrenal cortex Adrenal medulla Nephron Glomerular capsule Proximal convoluted tubule Loop of Henle Distal convoluted tubule Collecting duct E: F: Glomerular capsule Glomrulus _______ : functional units of kidney responsible for the formation of urine. Nephron Designed by Pyeongsug Kim, ©2010

_______________________ -The most reabsorption of solutes and water (except urea) ______________ -Loops down toward the medulla then up again into the cortex -Specializes in _____________ reabsorption ___________________ -Can reabsorb water and all solutes (except urea) Proximal convoluted tubule Loop of Henle NaCl and water Distal convoluted tubule Designed by Pyeongsug Kim, ©2010

Filtration ReabsorptionSecretion H 2 O Reabsorbtion __________ is the portion of the nephron responsible for filtering the blood. ___________________ contains microvilli increase the surface area for reabsorption of salt, water, etc. _________________________ located in adrenal cortex. Glomerular Excretion Know the parts of the nephron. Be able to give examples of a molecule or ion that is reabsorbed in each part of the nephron (proximal convoluted tubule, descending loop, etc.) Proximal convoluted tubule Glomerular capsule, Proximal, distal convoluted tubule Designed by Pyeongsug Kim, ©2010

Know the parts of the nephron. Be able to give examples of a molecule or ion that is reabsorbed in each part of the nephron (proximal convoluted tubule, descending loop, etc.) ____________ located in adrenal medulla. ____________ contains microvilli. *Distal convoluted tubule contains few microvilli relatively. ____________ has ADH receptors.; H 2 O reabsorption occurs. Loop of Henle Collecting duct Proximal, distal convoluted tubule ______________ is passively permeable water. ______________ is impermeable of water.; has Na/K+ pumps. ______________ is the place where secretion occurs. Desending limb Asending limb Distal convoluted tubule Designed by Pyeongsug Kim, ©2010

In the proximal tubule -(Filtration/reabsorption/secretion) -Active transports :___________&__________ :K+ reabsrobed -Passively follows Na+. :Cl- by electrical gradient. :H 2 O by osmosis. Na+/K+ pumpGlucose/Na+(coupled transport) In the glomerular -(Filtration/reabsorption/secretion) -Plasma water and solutes are filtrated-except _______. protein Designed by Pyeongsug Kim, ©2010

In the Descending limb -Passively permeable to water. -(Does/Does not) actively transport salt. In the Ascending limb -(Permeable/impermeable) to water. -(Does/Does not) actively transport salt. -Na+/K+ pumps - Cl+ follows passively the (Na+/K+). Know the parts of the nephron. Be able to give examples of a molecule or ion that is reabsorbed in each part of the nephron (proximal convoluted tubule, descending loop, etc.) Designed by Pyeongsug Kim, ©2010

Know the parts of the nephron. Be able to give examples of a molecule or ion that is reabsorbed in each part of the nephron (proximal convoluted tubule, descending loop, etc.) In the Distal convoluted tubule -(Filtration/reabsorption/secretion) -Impermeable to water; but last part is permeable. -(Does/Does not) actively transport salt. Cl+ follows passively the (Na+/K+). K+ secreted in the late distal tubule In the Collecting duct -(Filtration/H 2 O reabsorption/secretion) -Passively permeable to water by ____. -(Does/Does not) actively transport salt. Cl+ follows passively the (Na+/K+). K+ secreted under __________ ADH aldosterone Designed by Pyeongsug Kim, ©2010

Designed by Pyeongsug Kim, © Think simple! If something is TOO much in the body,..  kidneys throw away the too much things thru urine.  SECRETION and EXCRETION! If something is TOO little in the body,..  kidneys send the too little things back to body(the blood).  REABSORPTION!

ADH(Antidiuretic hormone) Plasma volume Plasma osmolity Osmotic pressure Detected by osmoreceptors in _____________ _____ is released Thirst ______ reabsorption Plasma volume Urine hypothalamus ADH H2OH2O Designed by Pyeongsug Kim, ©2010

Therefore, ADH decreases urine output(urine volume) but, increase the concentration in urine(Dark color in urine). Designed by Pyeongsug Kim, © ADH hold the body water (increase water reabsorption) and increase blood volume. ADH

-produced in the hypothalamus and stored in the posterior pituitary gland. -When blood osmolarity rises,(for example, dehydration)  ADH is released  increases water reabsorption in the distal tubule and collecting duct.  increase blood volume but decrease urine volume. Designed by Pyeongsug Kim, © ADH(cont’d) Aquaporin - ADH-responsive water channel. -found in distal tubule and collecting duct!

Regulation of plasma volum Renin -secreted by the _____________ cells. -Converts Angiotensinogen to ____________ juxtaglomerular Angiotensin I Designed by Pyeongsug Kim, ©2010

Designed by Pyeongsug Kim, © Salt deficit, Low blood volume, or pressure ____________ is produced Aldosterone secretion Vasoconstriction Na+, H2O retention K+ secretion ↓Urine volume ↑Blood pressure, ↑ Blood volume Renin ACE *ACE: A ngiotensin- c onverting e nzyme angiotensin II

Therefore, Renin and aldosterone increase Na+ level and blood volume but, decreases urine output(urine volume). Designed by Pyeongsug Kim, © Renin increases aldosterone. Aldosterone increase Na+ and water reabsorption. Renin and Aldosterone

Designed by Pyeongsug Kim, © Aldosterone produced in the adrenal cortex. When blood volume is low,  aldosterone is increased  at the distal tubules. ↑Na+ and Water reabsorption ↓K+ secretion Renin and Aldosterone (cont’d) -Renin secreted in Juxtaglomerular cells. increases aldosterone production. leads angiotensinII production. Vasoconstriction in Glomerus.  decreases GFR (Glomerular Filtration Rate)  leads to increased blood volume and pressure!!  Decreases Urine output!

Designed by Pyeongsug Kim, © ADH acts on the distal tubule and collecting duct. Aldosterone acts on the distal tubule.

CO=SV x HR ↑HR Designed by Pyeongsug Kim, ©2010

Sympathetic Nerves  (Vasodilation/vasoconstriction) in kidneys  ( ↓ )GFR:Glomerular Filtration Rate  ( ↓ ) Urine output  ( ↑ ) Blood volume ADH  H 2 O retention  ( ↓ ) Urine output Aldosterone  Na+, H 2 O retention, K+ secreted  ( ↓ ) Urine output Renin  AngiotensinII  (Vasoconstriction/vasodilation)  ( ↓ ) GFR  ( ↓ ) Urine output Designed by Pyeongsug Kim, ©2010

In the Distal convoluted tubule -(Filtration/reabsorption/secretion) -Impermeable to water; but last part is permeable. -(Does/Does not) actively transport salt. Cl+ follows passively the (Na+/K+). K+ secreted in the late distal tubule In the Collecting duct -(Filtration/H 2 O reabsorption/secretion) -Passively permeable to water by ____. -(Does/Does not) actively transport salt. Cl+ follows passively the (Na+/K+). K+ secreted under __________ -Permeable to urea ADH aldosterone OK! Look at this slide again!! Designed by Pyeongsug Kim, ©2010

Aldosterone -stimulates the secretion of ___ & ____ at DCT (distal convoluted tubule).  ↑pH in blood K+H+ Regulate blood pH by kidney -Normally, kidneys reabsorb HCO3- and excrete H+.  so, urine usually acidic (low pH, high H+). Designed by Pyeongsug Kim, © Think simple! If high pH(low H+) …  Kidneys keep H+. (↓H+ secretion). If low pH(high H+) …  Kidneys throw away H+. (↑H+ secretion).

Aldosterone (cont’d) -stimulates the secretion of ___ & ____. -Cause ↑ K+ secretion but, ↓H+ secretion  high H+(↓ pH) in blood K+H+ Designed by Pyeongsug Kim, © K+/ H+ -Secreted in the late of distal tubule and ___________________. -High H+ may decrease K+ secretion and increase H+ secretion. cortical collecting duct

During alkalosis(↑pH, low H+) -↓ H+ secretion -↓ HCO3- reabsorption -↑H+(↓pH) in blood Designed by Pyeongsug Kim, © Remember!!! Normally, kidneys reabsorb HCO3- and excrete H+. Kidneys try to keep H+.

Acidosis(↓pH; ↑H+)  ↑H+ secretion  ↓K+ secretion  ↓H+ /↑K+ in the blood  __________may occur. Hyperkalemia(↑K+)  ↑K+ secretion by ↑aldosterone  ↓H+ secretion  ↑H+ /↓K+ in the blood  ________ may occur. Hyperkalemia Acidosis *High K+ in the blood stimulates directly release of aldosterone(w/o renin or angiotensin I). Designed by Pyeongsug Kim, © In Acidosis, Kidneys try to throw away H+. Kidneys try to throw away K+.

Urea -Waste product of amino acid metabolism -Filtrated in the glomerular -Diffuse… into the asending limb out of collecting duct  trapped in the interstitial fluid  high osmolality in the medulla  H2O reabsorbed.  urine concentrated! H 2 O reabsoption occur in the collecting duct. Designed by Pyeongsug Kim, ©2010

Diuretic drugs -inhibit the reabsorption of water  increase urine volume.  lower blood volume. -for congestive heart failure, hypertension, edema - Lasix (furosemide), mannitol (osmotic diuretics) Designed by Pyeongsug Kim, ©2010

Lasix (Furosemide) -Diuretic drug -act on thick ascending limbs. -inhibit Na+ transport.  ↓Na+ reabsorption. (followed by Water)  ↓Water reabsorption.  increase urine volume.  decrease blood volume. Designed by Pyeongsug Kim, ©2010

Mannitol (Osmotic diuretics) -Diuretic drug -act on Last part of distal tubule and cortical collecting duct. -reduces osmotic reabsorption of water by reducing osmotic gradient.  pull water to the nephron.(↑water secretion)  increase urine volume.  decrease blood volume. Designed by Pyeongsug Kim, ©2010