70 Questions
What is the main cause of haemolysis when red blood cells are placed in hypotonic solutions?
Water entering the cell due to osmosis
What happens to the shape of red blood cells when they squeeze through capillaries?
They transform into irregular shapes
What factor prevents normal red blood cells from rupturing when deformed?
Excess cell membrane for the quantity of material inside
How is osmotic fragility defined?
The ease with which cells are broken down in hypotonic solutions
What does the osmotic fragility test help diagnose?
Diseases associated with RBC membrane abnormalities
What effect does stretching of the cell membrane have on red blood cells?
It leads to leakage of haemoglobin
What happens to red blood cells when they are placed in hypotonic solutions?
They swell due to water entering via osmosis
Which of the following is affected by various factors including membrane composition and integrity as well as surface-area to volume ratio?
Osmotic fragility
What happens when red blood cells are distended beyond a limit?
The cell membrane is stretched and its contents leak out
What is the main reason behind hemolysis when cells are placed in hypotonic solutions?
The entry of water into the cell due to osmosis
What is the measure of osmotic pressure?
Tonicity
What is the normal range of saline solutions where hemolysis begins?
0.55-0.45%
What does complete hemolysis indicate in the context of this experiment?
The saline becomes deep red with no red cells at the bottom
How do abnormal erythrocytes differ from normal ones in hereditary spherocytosis?
They are spherical instead of biconcave disk-shaped
Which disorder is caused by mutations in genes relating to membrane proteins?
Sickle cell anaemia
What is responsible for protecting RBCs from oxidative injury?
G6PD enzyme deficiency
What is the main cause of fragility of erythrocytes decrease in Thalassemia?
Excessive iron levels
What happens to RBCs in autoimmune hemolytic anemia?
They are destroyed by autoimmune antibodies
What causes the turning of the saline to red during partial hemolysis?
Loss of biconcave disk shape
What is responsible for making RBCs more prone to rupture in hereditary spherocytosis?
Loss of biconcave disk shape
Which condition results in an inadequate amount of glucose-6-phosphate dehydrogenase (G6PD) in the blood?
G6PD enzyme deficiency
What causes fragility of erythrocytes to increase in hereditary spherocytosis?
Genetic mutation
Hemolysis begins at a saline concentration of 0.55% and becomes complete at around 0.35%.
True
In autoimmune hemolytic anemia, autoimmune antibodies damage the structural proteins of RBCs.
True
Hereditary spherocytosis causes abnormal erythrocytes to be spherical rather than the normal biconcave disk shape.
True
G6PD deficiency results in an inadequate amount of glucose-6-phosphate dehydrogenase (G6PD) in the blood and occurs almost exclusively in females.
False
Sickle cell anemia causes abnormal erythrocytes that are more prone to rupture due to their abnormal shape.
True
Iron deficiency anemia leads to decreased osmotic fragility of RBCs.
False
Thalassemia causes a decrease in the fragility of erythrocytes.
True
G6PD deficiency protects RBCs from oxidative injury by providing an inadequate amount of glucose-6-phosphate dehydrogenase (G6PD) in the blood.
False
In the context of this experiment, complete hemolysis is indicated by a red-colored solution without any deposition of red cells at the bottom of the test tubes.
True
When there is some hemolysis, the color of saline changes to red because of Hb leaking out of the cells, with the unruptured cells forming a red dot at the bottom.
True
Fragility of erythrocytes increases in hereditary spherocytosis due to mutations in genes relating to membrane proteins.
True
Osmosis is the movement of water molecules through a semipermeable membrane from a region of low water concentration to high water concentration.
False
Red blood cells swell when placed in hypotonic solutions due to osmosis.
True
The shape of normal red blood cells can change remarkably as they squeeze through capillaries.
True
Deformation of normal red blood cells does not stretch the membrane greatly and does not rupture the cell.
True
Osmotic fragility is defined as the difficulty with which the cells are broken down in hypotonic solutions.
True
The osmotic fragility test is often performed to aid with diagnosis of diseases associated with RBC membrane abnormalities.
True
The osmotic fragility of cells is affected by various factors, including membrane composition, integrity, and surface-area to volume ratio.
True
Normal red blood cells are biconcave discs.
True
When cells are distended beyond a limit, the cell membrane is stretched and the contents of the cell leak out.
True
Haemoglobin leaks out and forms a clear pink solution when red cells are studied due to hemolysis.
True
The osmotic fragility test is used to determine the concentration of saline solutions in which cells are hemolysed.
True
The osmotic fragility test is primarily used to diagnose diseases associated with RBC membrane abnormalities.
True
The normal cell membrane has a great excess of cell membrane for the quantity of material inside, thus deformation does not stretch the membrane greatly and does not rupture the cell.
False
What is osmotic fragility?
The ease with which the cells are broken down in hypotonic solutions.
What causes red cells to swell when placed in hypotonic solutions?
Osmosis
What factors affect osmotic fragility?
Membrane composition, integrity, and surface-area to volume ratio
What happens to red blood cells when they are distended beyond a limit?
The cell membrane is stretched and the contents of the cell leak out
What is the main cause of hemolysis when red blood cells are placed in hypotonic solutions?
Deformation of the cell membrane
What is the effect of stretching of the cell membrane on red blood cells?
The contents of the cell leak out
What is the measure of osmotic fragility?
Concentration of saline solutions in which cells are hemolysed
How are normal red blood cells affected when they squeeze through capillaries?
Their shapes can change remarkably
What is the normal shape of red blood cells?
Biconcave discs
What happens when there is complete hemolysis in the context of the osmotic fragility test?
A red-colored solution without any deposition of red cells at the bottom of the test tubes
What do abnormal erythrocytes look like in hereditary spherocytosis?
Spherical rather than the normal biconcave disk shape
What is the main reason behind the color change of saline to red during partial hemolysis?
Hemoglobin leaking out of the cells
What is osmosis?
The movement of water molecules through a semipermeable membrane from a region of high water concentration to low water concentration.
Define osmotic pressure.
The pressure that would be required to stop water from diffusing through a semipermeable membrane by osmosis.
What is tonicity?
The measure of osmotic pressure.
At what saline concentration does hemolysis begin in the given experiment?
Between 0.55-0.45%
At what saline concentration does complete hemolysis occur in the given experiment?
Around 0.35%
What is the indicator of partial hemolysis in the given experiment?
Turning of the color of the solution to red in addition to deposition of part of the cells in the bottom of the test tubes.
What happens to the saline solution when there is complete hemolysis in the given experiment?
It becomes equally deep red with no red cells at the bottom of the tubes.
What causes fragility of erythrocytes to increase in hereditary spherocytosis?
Mutations in genes relating to membrane proteins.
What factor protects RBCs from oxidative injury in G6PD deficiency?
Inadequate amount of glucose-6-phosphate dehydrogenase (G6PD) in the blood.
What is the main cause of decreased osmotic fragility of RBCs in Thalassemia?
Thalassemia.
How do abnormal erythrocytes differ from normal ones in hereditary spherocytosis?
Abnormal erythrocytes are spherical rather than the normal biconcave disk shape.
What causes the shape of red blood cells to change in sickle cell anemia?
Abnormal shape due to mutations in genes relating to membrane proteins.
Study Notes
Osmotic Fragility
- Osmotic fragility is defined as the difficulty with which red blood cells are broken down in hypotonic solutions.
- The osmotic fragility test is performed to aid in the diagnosis of diseases associated with RBC membrane abnormalities.
- Osmotic fragility is affected by various factors, including membrane composition, integrity, and surface-area to volume ratio.
Hemolysis
- Hemolysis occurs when red blood cells are placed in hypotonic solutions, causing them to swell and eventually lyse due to osmotic pressure.
- The main cause of hemolysis is the stretching of the cell membrane, which leads to lysis.
- Hemolysis begins at a saline concentration of 0.55% and becomes complete at around 0.35%.
Red Blood Cells
- Normal red blood cells are biconcave discs, but they can change shape remarkably as they squeeze through capillaries.
- Deformation of normal red blood cells does not stretch the membrane greatly and does not rupture the cell.
- Red blood cells swell when placed in hypotonic solutions due to osmosis.
Hereditary Spherocytosis
- Hereditary spherocytosis causes abnormal erythrocytes to be spherical rather than the normal biconcave disk shape.
- Fragility of erythrocytes increases in hereditary spherocytosis due to mutations in genes relating to membrane proteins.
- Abnormal erythrocytes in hereditary spherocytosis are more prone to rupture due to their abnormal shape.
Other Conditions
- G6PD deficiency results in an inadequate amount of glucose-6-phosphate dehydrogenase (G6PD) in the blood, which protects RBCs from oxidative injury.
- Thalassemia causes a decrease in the fragility of erythrocytes.
- Sickle cell anemia causes abnormal erythrocytes that are more prone to rupture due to their abnormal shape.
- Iron deficiency anemia leads to decreased osmotic fragility of RBCs.
Osmosis and Osmotic Pressure
- Osmosis is the movement of water molecules through a semipermeable membrane from a region of low water concentration to high water concentration.
- Osmotic pressure is the measure of osmotic fragility.
- Tonicity refers to the ability of a solution to cause a cell to swell or shrink.
Test your knowledge of osmotic fragility of red blood cells with this quiz. Learn about the process of haemolysis when red cells are placed in hypotonic solutions and the characteristics of red blood cells.
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