Tonicity

A 0.3 m glucose solution, which is 0.3 Osm, or 300 milliosmo-lal (300 mOsm), has the same osmolality and osmotic pressure as plasma. The same is true of a 0.15 m NaCl solution, which ionizes to produce a total concentration of 300 mOsm. Both of these solutions are used clinically as intravenous infusions, labeled 5% dextrose (5 g of glucose per 100 ml, which is 0.3 m) and normal saline (0.9 g of NaCl per 100 ml, which is 0.15 m). Since 5% dextrose and normal saline have the same osmolality as plasma, they are said to be isosmotic to plasma.

The term tonicity is used to describe the effect of a solution on the osmotic movement of water. For example, if an isos-motic glucose or saline solution is separated from plasma by a membrane that is permeable to water, but not to glucose or NaCl, osmosis will not occur. In this case, the solution is said to be isotonic (from the Greek isos = equal; tonos = tension) to plasma.

Red blood cells placed in an isotonic solution will neither gain nor lose water. It should be noted that a solution may be isos-motic but not isotonic; such is the case whenever the solute in the isosmotic solution can freely penetrate the membrane. A 0.3 m urea solution, for example, is isosmotic but not isotonic because the cell membrane is permeable to urea. When red blood cells are placed in a 0.3 m urea solution, the urea diffuses into the cells until its concentration on both sides of the cell membranes becomes equal.

Isotonic solution

Hypotonic solution Hypertonic solution

Hypotonic solution Hypertonic solution

Hypotonic Osmosis

■ Figure 6.11 Red blood cells in isotonic, hypotonic, and hypertonic solutions. In each case, the external solution has an equal, lower, or higher osmotic pressure, respectively, than the intracellular fluid. As a result, water moves by osmosis into the red blood cells placed in hypotonic solutions, causing them to swell and even to burst. Similarly, water moves out of red blood cells placed in a hypertonic solution, causing them to shrink and become crenated.

■ Figure 6.11 Red blood cells in isotonic, hypotonic, and hypertonic solutions. In each case, the external solution has an equal, lower, or higher osmotic pressure, respectively, than the intracellular fluid. As a result, water moves by osmosis into the red blood cells placed in hypotonic solutions, causing them to swell and even to burst. Similarly, water moves out of red blood cells placed in a hypertonic solution, causing them to shrink and become crenated.

Meanwhile, the solutes within the cells that cannot exit—and which are therefore osmotically active—cause osmosis of water into the cells. Red blood cells placed in 0.3 m urea will thus eventually burst.

Solutions that have a lower total concentration of solutes than that of plasma, and therefore a lower osmotic pressure, are hypo-osmotic to plasma. If the solute is osmotically active, such solutions are also hypotonic to plasma. Red blood cells placed in hypotonic solutions gain water and may burst—a process called hemolysis. When red blood cells are placed in a hypertonic solution (such as sea water), which contains osmotically active solutes at a higher osmolality and osmotic pressure than plasma, they shrink because of the osmosis of water out of the cells. This process is called crenation (crena = notch) because the cell surface takes on a scalloped appearance (fig. 6.11).

Intravenous fluids must be isotonic to blood in order to maintain the correct osmotic pressure and prevent cells from either expanding or shrinking from the gain or loss of water. Common fluids used for this purpose are normal saline and 5% dextrose, which, as previously described, have about the same osmolality as normal plasma (approximately 300 mOsm). Another isotonic solution frequently used in hospitals is Ringer's lactate. This solution contains glucose and lactic acid in addition to a number of different salts.

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Responses

  • ausilio
    When is an isosmotic solution not isotonic?
    6 years ago
  • demsas
    How does 0.3M glucose affect red blood cells?
    6 years ago
  • Lena
    What is the osmolarity of a solution that is isotonic to human red blood cells?
    6 years ago
  • luam
    Why is 300 mosm glucose isotonic?
    6 years ago
  • SELAM BRHANE
    Why 300 mosm glucose was isotonic, but 300 mosm urea was hpotonic?
    6 years ago
  • riitta
    What results when red blood cell is placed in a 0.3M NaCl sollution?
    6 years ago
  • FILOMENA
    What is the effect of 0.3m glucose on red blood cells?
    6 years ago
  • charles
    How to make a hypoosmotic and isotonic solution?
    6 years ago
  • theodore
    Why 300 mOsm glucose was isotonic, but 300 mosm urea was hypotonic?
    6 years ago
  • furuta
    Why is 300 osm glucose isotonic and 300 osm urea hypotonic to red blood cells?
    6 years ago
  • eva
    How is a 0.3m urea solution isotonic and hypotonic?
    6 years ago
  • alesha russell
    Is 0.3 M glucose the same as 0.15 M nacl?
    6 years ago
  • christin
    Which solution is not isotonic to plasma?
    6 years ago
  • bernd
    Is blood plasma isotonic to 0.15 m nacl?
    6 years ago
  • melissa
    How are isotonic and hypertonic solutions used in hospitals?
    6 years ago
  • Lukas
    How are solutions isosmotic but not isotonic?
    6 years ago
  • dahlak
    Why does cell burst when red blood cell in isosmotic solution of urea?
    6 years ago
  • adiam
    Why will placing a red blood cell in urea burst?
    6 years ago
  • Nilde
    Why do red blood cells burst when in urea solution?
    6 years ago
  • JULIAN
    Why is a 0.3 m urea solution is good for intravenous infusions?
    6 years ago
  • gabriella
    What is tonicity 0.15M of NaCl?
    6 years ago
  • paula
    Which solution of red blood cells are isoosmotic, isotonic, hypotonic?
    6 years ago
  • Linda
    What is the tonicity of a solution urea compared to red blood cell?
    6 years ago
  • olo rumble
    Is urea a isotonic or hypotonic solution for red blood cells?
    6 years ago
  • maciej
    What environmentalal tonicity causes red blood cells to become crenated?
    6 years ago
  • anne
    What would result if the tonicity of the solution is not isotonic to the blood cell.?
    5 years ago
  • stig hasti
    Why do muscle cells gain weight in isosmotic urea?
    5 years ago
  • magnus
    How would isotnic saline and dextrose in water affect the human blood?
    5 years ago
  • Senay Yonas
    Why is urea isoosmotic and hypotonic?
    5 years ago
  • Kaija Uusipaikka
    Why 300mOsm of urea is not isotonic?
    5 years ago
  • lea freeh
    Why a red blood cell would burst in tonicity?
    5 years ago
  • anna
    Is 0.35 M glucose hypertonic to 0.15 M NaCl?
    5 years ago
  • Fernando
    Is blood plasma isotonic hypotonic or hypertonic?
    5 years ago
  • Hessu
    How do plasma osmolality affect the physiology of erythrocytes?
    5 years ago
  • gofreddo
    What Solutions that have a tonicity equal to blood plasma are called?
    5 years ago
  • Antonino Colombo
    Why does NaCl give blood cell isotonic tonicity?
    5 years ago
  • Maarit
    What environmental tonicity causes red blood cells to become crenated?
    5 years ago
  • amethyst
    What effect would a isotonic saline and 5% dextrose in water have on red blood cells?
    5 years ago
  • amanuel
    Why is an iso osmotic solution NOT always isotonic?
    5 years ago
  • travis
    Why does hemolysis occur into isosmotic solution of urea?
    5 years ago
  • savannah mcintosh
    Is a .15 m nacl solution isotonic to blood plasma?
    5 years ago
  • jarkko
    What is isosmotic to 300 mosm?
    5 years ago
  • linda smith
    How to ensure that saline is isotonic with blood?
    5 years ago
  • amerigo
    What affect would a hypertonic solution of glucose have on blood plasma levels?
    5 years ago
  • NILS
    Why is urea isosmotic to plasma but not isotonic?
    3 years ago
  • Judy
    Why 300 mM urea is isoosmotic and hypotonic at the same time?
    3 years ago
  • gabriele
    Is urea hypotonic or hypertonic?
    2 years ago
  • Segan
    Why does isoosmltic solution of urea make cells swell?
    2 years ago
  • elvia
    What effect will 0.3M urea have on a red blood cell?
    2 years ago
  • Kaarle
    Is a 0.15M NaCl solution hypertonic to blood?
    2 years ago
  • debra aparicio
    Why will isotonic solution of urea cause red blood cells to swell?
    2 years ago
  • julia
    What will happen if the tonicity not maintained?
    2 years ago
  • MELILOT WHITFOOT
    Is the isotonicity of glucose and Nacl the same?
    2 years ago
  • lori donaldson
    Does tonicity affect urea?
    2 years ago
  • Sherry
    What is isosomotic Nacl?
    2 years ago
  • sigismond burrows
    Is urea acting on tonicity ?
    2 years ago
  • gaetana
    What is the effect of isosmotic solution has on Red blood cells?
    2 years ago
  • terry
    Why does an isotonic urea solution cause hemolysis?
    2 years ago
  • Veera Varis
    What concentration of dextrose is isotonic to red blood cells?
    2 years ago
  • pandora
    WHY IS urea and NaCl hypertonic?
    2 years ago
  • TUOMO VASALA
    What will be effect of hypotonic and hypertonic solution of rbc to normal person?
    2 years ago
  • leila
    How much concentration of glucose is isotonic to blood?
    2 years ago
  • zula
    Which solution is hypertonic to the blood, NaCl or glucose?
    2 years ago
  • Lily Twofoot
    What happens when normal blood.com is placed in a solution isotonic?
    2 years ago
  • Veera
    Which blood toncity in human blood?
    2 years ago
  • Filmon
    Are equimolar solution of urea and NaCl isoosmotic?
    2 years ago
  • anneli
    Why is isotonic urea permeable to a cell membrane causing hemolysis?
    2 years ago
  • Libby
    Why is 300mosm/l urea hypotonic?
    1 year ago
  • angelina
    What is heart tonicity?
    1 year ago
  • VESA MATTILA
    How does tonicity relate to crenation and hemolysis?
    1 year ago
  • Zemzem
    Do solutions in which haemolysus occur are isosmotic isotonic?
    1 year ago
  • caiden
    Why is glycerin and urea hypotonic to red blood cells and glucose not?
    1 year ago
  • Sesuna
    What are urea nacl and glucose solutions?
    1 year ago
  • semhar
    What is the solution to 300 mOsM isotonic cell?
    1 year ago
  • anke
    Is 5.3% urea isotonic or hypertonic to RBC?
    1 year ago
  • salvia
    What percent of urea is isotonic to plasma?
    1 year ago
  • bruno
    Is 10 percent urea hypertonic in the body?
    1 year ago
  • tyko
    What happened when a same IS placed in hypertonic and hypnotic solution respectively?
    1 year ago
  • NEGISTI
    What is the amount of Nacl per 100 ml Human blood?
    1 year ago
  • Tarquinio
    What is myocardial tonicity?
    1 year ago
  • Jerry
    Is the human blood stream hypotonic or hypertonic?
    1 year ago
  • Faramond
    When a red blood cell is put in a hypertonic solution of glucose, does the glucose move in?
    1 year ago
  • BRIGITTE
    What happens to a redblood cell it is placed in a solution of high osmolarity?
    1 year ago
  • zula
    Is glucose isotonic hypotonic or hypertonic?
    1 year ago
  • virgilio
    What will happen to red blood cell in 0.15M urea?
    1 year ago
  • rufus
    What is the effect of putting red blood cells in urea?
    1 year ago
  • virpi
    Can red cells shrink in urea?
    1 year ago
  • NASIH
    How urea hemolyse rbc?
    1 year ago
  • regina
    Why idvNaCl isotonic withvglucose at a lower concentration?
    1 year ago
  • MICHAEL
    Why is urea isosmotic but hypertonic to erythrocytes?
    1 year ago
  • Menegilda
    How does dexyros 5% prevent hemolyses?
    1 year ago
  • aliisa
    What happen rbc added in isoosmatic?
    1 year ago
  • vincent
    What is the effect of a 0.3 M Concentration of urea on a red blood cell?
    1 year ago
  • abelino
    Is glucose isosmotic?
    1 year ago
  • laila p
    Is blood plasma .15 molar nacl?
    11 months ago
  • juha
    What concentration is glucose isotonic to human?
    11 months ago
  • Tanta
    How dextrose 5% is physiologically hypotonic?
    11 months ago
  • Petra
    Why does urea haemolysis red blood cells?
    10 months ago
  • matthias
    What effect does physiological saline and urea have on red cells?
    10 months ago
  • DAMIANA
    What is the effect of 0.3 molar of urea on red blood cell?
    10 months ago
  • sampsa ukkonen
    What is the effect of 0.3M urea when red blood cells are placed in the solution?
    10 months ago
  • halfred
    What causes hemolysis of RBCs in 0.3M urea?
    10 months ago
  • merimac
    What happens to red blood cells when placed in 0.3 molar urea?
    10 months ago
  • celendine
    What happens to red blood cells when placed in 0.15 molar sodium chloride?
    10 months ago
  • URHO
    What will happen to a red blood cell placed in 0.3Molar glucose?
    10 months ago
  • ermias dawit
    What happen happens to red blood cell when placed in urea 0.3 molar?
    10 months ago
  • tuula
    Why is Nacl said to be isotonic to glucose at lower concentration?
    10 months ago
  • MERRY
    Why is sodium chloride isotonic with glucose at a lower molar concentration?
    10 months ago
  • tauno
    Why is there no haemolysis with 0.15 Nacl?
    10 months ago
  • maddalena
    What is the effect of RBC when put to 0.3M ureal?
    10 months ago
  • adelia
    What happens when you place a red blood cell in 0.3M urea?
    10 months ago
  • ZAK
    What tonicity of 0.15M Nacl to RBCs?
    10 months ago
  • maik
    What happens ree blood cells are placed in 0.3M glucose solution?
    10 months ago
  • jeffrey
    Do haemolysis occur in urea?
    10 months ago
  • lisa
    Why does a 0.3 molar concertation of glycerol cause haemolysis to red blood cells?
    10 months ago
  • stephanie
    Why does urea heamolyse blood?
    10 months ago
  • lena
    What happens to red blood cells in isosmotic urea?
    10 months ago
  • paavo johanson
    How does 0.3m Glucose cause hemolysis when added to blood?
    9 months ago
  • Lodovico
    Why do red blood cells haemolyse when urea has been added?
    9 months ago
  • yrj
    Why does 0.15M NaCl not cause haemolysis to red blood cell?
    9 months ago
  • habte
    What will happen if red blood cells are placed in 0.15M glucose?
    9 months ago
  • amanuel
    Are equilmolar solutions of urea and sodium chloride isoosmatic?
    9 months ago
  • futsum amanuel
    Does urea penetrate the membrane of red blood cells?
    9 months ago
  • onni
    What Causes ureal to be red as blood?
    9 months ago
  • Samuel
    What effect does urea have on tonicity of red blood cells?
    9 months ago
  • MARIO BAUMGAERTNER
    Can 0.3M urea hemolyse a red blood cell?
    9 months ago
  • AZEGLIO MARCHESI
    Why does 0.3M urea lead to hemolysis?
    9 months ago
  • prima
    Why doesnt glucose cause hemolysis of red blood cell?
    9 months ago
  • Zain
    Why do RBCs hemolyse in glycerol?
    9 months ago
  • aija
    Why does urea hemolyse blood cells?
    9 months ago
  • Palmira
    Can a 0.3M glucose solution cause hemolysis?
    9 months ago
  • Pansy
    Can isotonic solution cause haemolysis?
    9 months ago
  • euan
    What is the osmolarity of 0.3 molar solution of urea?
    9 months ago
  • HANNA-MARI
    What is the concentration of urea in red blood cells in molar?
    9 months ago
  • elanor goodbody
    Does urea cause osmosis on red blood cells?
    9 months ago
  • danielle
    What causes the red blood cells not to undergo haemolysis when placed in 0.15NaCl?
    9 months ago
  • reijo
    Can 3% Saline cause hemolysis?
    9 months ago
  • Jordan
    Why do rbc breaks in isotonic solution of urea?
    9 months ago
  • luca
    Why does rbcs rupture in isoosmotic urea solution?
    9 months ago
  • Henry Kelly
    Why does RBC burst when placed in 0.3 % NaCl?
    8 months ago
  • isengrim
    Why 0.3M of NaCl solution crenated red blood cells?
    8 months ago
  • ROMOLA
    Why does urea produce different osmotic result on red blood cell?
    8 months ago
  • amy
    Why isotonic solution of NaCl and Urea produce different osmotic phenomena on the red blood cells?
    8 months ago
  • Adaldrida
    Is urea hyposmotic to red blood cells or hypeeosmotic?
    8 months ago
  • bianca
    Why will isotinic sodium chloride and urea produce different effects on RBC?
    8 months ago
  • Jamie
    Why is it that NaCl of any concentration does not cause haemolysis?
    8 months ago
  • Tewolde
    Why does isotonic NaCl and urea produce different phenomenom on red blood cells?
    8 months ago
  • nora
    Why isotonic nacl and urea produced different osmotic phenomena on rbcs?
    8 months ago
  • kayleigh
    Is hypertonic urea solution still permeable to red blood cell?
    8 months ago
  • Arabella Sabbatini
    Why did the solutio. with NaCl and blood not haemolyse?
    8 months ago
  • esko
    Why does urea penetrate through the red blood cells quickly?
    8 months ago
  • markus rothstein
    What makes RBCs haemolyse more faster ın urea?
    8 months ago
  • leena
    Can urea diffuse into red blood cells?
    8 months ago
  • THORSTEN
    What is the effect of urea concentration on rbc membrane?
    8 months ago
  • anja
    Why do red blood cells lysed in urea?
    8 months ago
  • aamu
    Why isotonic solution of Nacl and Urea produce different osmotic phenomena on red blood cell?
    7 months ago
  • magnus fairbairn
    What happened when put red blood cell in urea?
    7 months ago
  • massimiliano
    What happen when RBC is placed in Urea, NaCl, Glucose and saponin?
    7 months ago
  • tito
    How is isotonic contribute to blood?
    7 months ago
  • welde
    Is 0.15 M glucose is an isotonic solution?
    6 months ago
  • Ines
    Are equimolar solution of urea and sodium chloride isosmotic?
    6 months ago
  • Luwam Alem
    Why isotonic solution in urea and thiourea caused the red cell to swell and haemolysis?
    6 months ago
  • Louella
    Does dextrose contributes to tonicity?
    6 months ago
  • Fabrizia
    What will happend when rbc is suspended in tonicity?
    6 months ago
  • Cassie Henderson
    What tonicity effect of nacl have on the body?
    5 months ago
  • Emma
    Why is it that water lyse RBC but saline does not?
    5 months ago
  • Belisarius
    How to calculate concentration of glucose that is isoosmotic with plasma?
    4 months ago
  • Nasih
    What are the effects of NaCl, glucose, urea and saponin on red blood cells?
    4 months ago
  • MARCEL
    Why does isotonic solutions of sodium chloride and urea produce diferrent results on rbc?
    4 months ago
  • tommy lepist
    Can sodium chloride penetrate red blood cells?
    3 months ago
  • danny
    Why does hemolysis occur when blood is put in Urea concentration?
    3 months ago
  • maire
    Does the red blood cell contain glucose and urea?
    3 months ago
  • Guendalina Genovese
    Why does 0.15M of sodium chloride causehaemolysis?
    3 months ago
  • fernando milani
    Why doesnt 0.15 NaCl cause hemolysis?
    3 months ago
  • helen daniel
    What happened to the red blood cells when placed in 0.3M of urea?
    3 months ago
  • kaarlo
    Why does 0.3M of urea when mixed with blood cause heamolysis?
    3 months ago
  • Peony
    Why does 0.3M glucose when mixed with blood cause no heamolysis?
    3 months ago
  • elisa
    What happens when RBC becomes added to a solution containing 0.15m nacl and soap?
    3 months ago
  • zufan yonatan
    What is 50%urea solution and 5% glucose and state effect on red cell?
    3 months ago
  • Nebay
    Can 0.3 urea haemolyse a red blood cell?
    3 months ago
  • lalli lehtonen
    What happens when you place red blood cells in urea conrntration?
    3 months ago
  • Eeva
    What happens when you place red blood cells in glecerol conentration?
    3 months ago
  • juliane
    Does haemolysis take place in 0.3M glucose solution?
    3 months ago
  • hildigard
    How does high nacl cause hemolysis?
    3 months ago
  • pippin hornblower
    How long does it take for red blood cells to hemolyse in glucose?
    3 months ago
  • topias filatov
    Why do red blood cells burst in 0.3M glycerol?
    3 months ago
  • Mhret
    Does the concentration of sodium chloride affect haemolyses of blood cella?
    3 months ago
  • Markus
    Why does glucose take long to haemolyse?
    3 months ago
  • Azzeza
    How does red blood cell behaves when placed in urea?
    3 months ago
  • ester
    What caused rbcs to separate into layersin urea?
    2 months ago
  • Caiden
    What is the effect of urea of any strength on red blood cells?
    2 months ago
  • cayden
    Why isomotic NaCl and Urea produce different osmotic phenomena on the red blood cells?
    2 months ago
  • semhar tewolde
    When Rbc suspended in hyptonic solutio what will occur?
    2 months ago
  • Kirk
    How does fluid tonicity affect the body?
    2 months ago
  • mark
    Is 0.3 molar of sodium chloride isosmotic?
    2 months ago
  • Leah
    What plasmic tonicity?
    2 months ago
  • Trudy Parks
    Is urea osmotically active?
    2 months ago
  • Shelly
    How are hemolysis and crenation prevented in the bloodstream?
    2 months ago
  • franciszek scott
    What is the effect of 0.3 M glucose solution the RBCS?
    1 month ago
  • Assunta
    Is ammonium chloride an example of isosmotic?
    1 month ago
  • sampsa
    Is 0.3M glucose isoosmotic with red cell?
    1 month ago
  • bildad
    Why isomotic Nacl,glucose,urea and NH4cl produce different osmotic phenomena on RBC?
    1 month ago
  • amanuel
    What is the behaviour of red blood cell in glucose with concentration 0.3?
    1 month ago
  • eden
    How does red blood cell tonicity in body?
    1 month ago
  • asmara senay
    Is the effect of urea solution on red blood cells physical or chemical?
    17 days ago
  • feaven
    What chemical property of urea solution causes hemolysis of red blood cell?
    17 days ago
  • seija
    Which concentration of glucose and sodium chloride in terms molarity lyses the cells?
    15 days ago
  • salvo sal
    What molar concentration of glucose and sodium chloride is isotonic as judged by limits of fragility?
    7 days ago
  • dominik nussbaum
    What is the time required for red blood cells to haemolyse when placed in urea solution?
    7 days ago

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