Hypertonic does not means swelling but instead hypertonic means that any external solution has a high solute concentration and low water concentration when compared to body fluids.
The net movement of water in a hypertonic solution will be out of the body and into the solution.
Urine becomes hypertonic because of a result of excretion of excess solutes and the urine becomes hypotonic due to the excretion of excess water and hypertonic urine is highly concentrated urine.
The urine is in the distal convoluted tubule when it's hypertonic and when the urine is hypotonic it passes into collecting tubule.
Hypertonic urine is highly concentrated urine that results from the excretion of excess solutes.
Hypotonic urine is urine that results from excretion of excess water.
In hypotonic urine, the concentration of water is more as compared to its solutes, whereas in hypertonic urine, the concentration of water is low as compared to its solutes.
When there is a threat of excessive water loss from the body of an animal, the urine excreted needs to be hypertonic and not hypotonic.
When urine passes into collecting tubule it becomes hypotonic. Urine is isotonic in proximal convolute tubule.
In the presence of antidiuretic hormone (ADH), water is mainly reabsorbed from the collecting duct and the fluid thus logically becomes hypertonic, i.e. concentrated.
Hypertonic dehydration, also known as hypernatremia, refers to an imbalance of water and sodium in the body characterized by relatively increased levels of sodium.
Generally, when water is excreted from the body, electrolyte (e.g., sodium) concentrations in the blood increase.
Urea leaks from the lower portion of collecting duct and contributes to a high solute concentration.
Water leaves descending limb of the loop of Henle, returning to the blood.
Hence, urine is hypertonic to blood and isotonic to medullary plasma.
If a cell encounters a hypotonic environment, (like pure water for instance), water will diffuse into the cell and the cell will begin to swell.
This can of course lead to an explosion of sorts.
Hypotonic dehydration is mostly caused by diuretics, which cause more sodium loss than water loss.
Hypotonic dehydration is characterized by low sodium and osmolality.
The hypertonicity is due to the high concentration of Na+ and Cl− ions in the medulla, resulting from the countercurrent multiplier activity of the loops of Henle.
Thus, an increasingly concentrated urine is produced.
The ability of the kidney to produce urine that is hypertonic to the blood plasma is due to the loop of Henle.
The loop of Henle does not concentrate the urine directly; rather, it functions as a countercurrent multiplier creating a concentration gradient in the surrounding medulla.
The hypertonicity of the renal medulla is of fundamental importance for normal renal function, especially for processes involved in urine concentration.