Home
Class 12
BIOLOGY
Osmolarity close to cortex is 300 mOsmol...

Osmolarity close to cortex is 300 mOsmol/L and 1200 mOsmol/L in the inner medulla, the gradient mainly caused by

A

bicarbonates and glucose

B

glucose and amino acids

C

NaCl and urea

D

NaCl only

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the osmolarity gradient between the cortex and inner medulla of the kidney, we can follow these steps: ### Step-by-Step Solution: 1. **Understand Osmolarity**: - Osmolarity refers to the concentration of solutes in a solution. In this case, we are comparing the osmolarity in the kidney's cortex (300 mOsmol/L) and the inner medulla (1200 mOsmol/L). 2. **Identify the Regions**: - The kidney is divided into different regions: the cortex, outer medulla, and inner medulla. The cortex has a lower osmolarity compared to the inner medulla. 3. **Recognize the Gradient**: - The significant difference in osmolarity (from 300 to 1200 mOsmol/L) indicates a concentration gradient. This gradient is essential for the kidney's ability to concentrate urine. 4. **Determine the Causes of the Gradient**: - The osmolarity gradient is primarily caused by the reabsorption of specific solutes. The key solutes involved in creating this gradient are sodium chloride (NaCl) and urea. 5. **Explain the Role of NaCl and Urea**: - NaCl is actively reabsorbed in the nephron, particularly in the loop of Henle, which contributes to the high osmolarity in the inner medulla. - Urea also plays a crucial role as it is reabsorbed and contributes to the osmotic gradient, enhancing the kidney's ability to concentrate urine. 6. **Conclude the Answer**: - Therefore, the gradient from 300 mOsmol/L in the cortex to 1200 mOsmol/L in the inner medulla is mainly caused by the presence of NaCl and urea. ### Final Answer: The gradient is mainly caused by **NaCl and urea**. ---
Promotional Banner

Topper's Solved these Questions

  • EXCRETORY PRODUCTS AND THEIR ELIMINATION

    AAKASH SERIES|Exercise EXERCISE - I (REGULATION OF KIDNEY FUNCTION)|11 Videos

  • EXCRETORY PRODUCTS AND THEIR ELIMINATION

    AAKASH SERIES|Exercise EXERCISE - I (MICTURITION)|4 Videos

  • EXCRETORY PRODUCTS AND THEIR ELIMINATION

    AAKASH SERIES|Exercise EXERCISE - I (FUNCTION OF THE TUBULES)|18 Videos

  • EVOLUTION

    AAKASH SERIES|Exercise EXERCISE - III( PREVIOUS AIPMT/NEET QUESTIONS)|38 Videos

  • HUMAN REPRODUCTION

    AAKASH SERIES|Exercise EXERCISE-III|55 Videos

Similar Questions

Explore conceptually related problems

High osmolarity of inner medullary interstitium is mainly caused by -

The word fluid means a substance having particles which readily of its magnitude (a small shear stress, which may appear to be of negligible will cause deformation in the fluid). Fluids are charactrised by such properties as density. Specific weight, specific gravity, viscosity etc. Density of a substance is defined as mass per unit volume and it is denoted by. The specific gravity represents a numerical ratio of two densities, and water is commonly taken as a reference substance. Specific gravity of a substance in written as the ratio of density of substance to the density of water. Specific weight represents the force exerted by gravity on a unit volume of fluid. It is related to the density as the product of density of a fluid and acceleration due to gravity. Viscosity is the most important and is recognized as the only single property which influences the fluid motion to a great extent. The viscosity is the property by virtue of which a fluid offers resistance to deformation under the influenece if shear force. The force between the layers opposing relative motion between them are known as forces of viscosity. When a boat moves slowly on the river remains at rest. Velocities of different layers are different. Let v be the velocity of the level at a distance y from the bed and V+dv be the velocity at a distance y+dy . The velocity differs by dv in going through a distance by perpendicular to it. The quantity (dv)/(dy) is called velocity gradient. The force of viscosity between two layers of a fluid is proportional to velocity gradient and Area of the layer. F prop A & F prop (dv)/(dy) F= -etaA(dv)/(dy) ( -ve sign shown the force is frictional in nature and opposes relative motion. eta coefficient of dynamic viscosity Shear stress (F)/(A)= -eta(dv)/(dy) and simultaneously kinematic viscosity is defined as the dynamic viscosity divided by the density. If is denoted as v . The viscosity of a fluid depends upon its intermolecular structure. In gases, the molecules are widely spaced resulting in a negligible intermolecular cohesion, while in liquids the molecules being very close to each other, the cohesion is much larger with the increases of temperature, the cohesive force decreases rapidly resulting in the decreases of viscosity. In case of gases, the viscosity is mainly due to transfer of molecular momentum in the transerve direction brought about by the molecular agitation. Molecular agitation increases with rise in temperature. Thus we conclude that viscosity of a fluid may thus be considered to be composed of two parts, first due to intermolecuar cohesion and second due to transfer of molecular momentum. Viscosity of liquids

The word fluid means a substance having particles which readily of its magnitude (a small shear stress, which may appear to be of negligible will cause deformation in the fluid). Fluids are charactrised by such properties as density. Specific weight, specific gravity, viscosity etc. Density of a substance is defined as mass per unit volume and it is denoted by. The specific gravity represents a numerical ratio of two densities, and water is commonly taken as a reference substance. Specific gravity of a substance in written as the ratio of density of substance to the density of water. Specific weight represents the force exerted by gravity on a unit volume of fluid. It is related to the density as the product of density of a fluid and acceleration due to gravity. Viscosity is the most important and is recognized as the only single property which influences the fluid motion to a great extent. The viscosity is the property by virtue of which a fluid offers resistance to deformation under the influenece if shear force. The force between the layers opposing relative motion between them are known as forces of viscosity. When a boat moves slowly on the river remains at rest. Velocities of different layers are different. Let v be the velocity of the level at a distance y from the bed and V+dv be the velocity at a distance y+dy . The velocity differs by dv in going through a distance by perpendicular to it. The quantity (dv)/(dy) is called velocity gradient. The force of viscosity between two layers of a fluid is proportional to velocity gradient and Area of the layer. F prop A & F prop (dv)/(dy) F= -etaA(dv)/(dy) ( -ve sign shown the force is frictional in nature and opposes relative motion. eta coefficient of dynamic viscosity Shear stress (F)/(A)= -eta(dv)/(dy) and simultaneously kinematic viscosity is defined as the dynamic viscosity divided by the density. If is denoted as v . The viscosity of a fluid depends upon its intermolecular structure. In gases, the molecules are widely spaced resulting in a negligible intermolecular cohesion, while in liquids the molecules being very close to each other, the cohesion is much larger with the increases of temperature, the cohesive force decreases rapidly resulting in the decreases of viscosity. In case of gases, the viscosity is mainly due to transfer of molecular momentum in the transerve direction brought about by the molecular agitation. Molecular agitation increases with rise in temperature. Thus we conclude that viscosity of a fluid may thus be considered to be composed of two parts, first due to intermolecuar cohesion and second due to transfer of molecular momentum. If the velocity profile is given by v=(2)/(3)y-y^(2)v is velocity in m//sec y is in meter above the bad. Determine shear stress at y=0.15m , & eta=0.863 Ns//m^(2)

The plane wall of an oven is of thickness L = 0.05 m and is exposed to the surrounding at 300 K. The outer surface of the oven exposed to the surrounding is at temperature 320 K in steady state. The energy radiated (In W//m^2 ) by outer surface is proportional to the temperature difference between the surface and the surrounding, with proportionality constant 20 W//m^2K . What is the temperature of inner surface of the oven in steady state if the wall has a thermal conductivity of K = 0.5 W/mK

The figure given below shows three glass chambers that are connected by valves of negligible volume. At the outset of an experiment, the valves are closed and the chambers contain the gases as detailed in the diagram. All the chambers are at the temperature of 300 K and external pressure of 1.0 atm . Which of the following represents the total kinetic energy of all the gas molecules after both valves are opened? ( R=0.082 atm L K^(-1) mol^(-1)=8.314 JK^(_1)mol^(-1) )

3.00 mol of PCl_(5) kept in 1L closed reaction vessel was allowed to attain equilibrium at 3.80 K . Calculate composition of the mixture at equilibrium K_(c) = 1.80