Osmoregulation
Osmoregulation is the physiological response of an organism to maintain a constant water balance regardless of its surroundings, making up for if water if lost and avoid access water. This ensures that a constant osmolality of body fluids is kept. The average human is around 55 to 60%
water weight, so it is essential that it is kept under control (Kenneth S.Saladin, ©2012). Water is lost due to things like evaporation, excretion.
Because water cannot be transported through cell membranes, a change in the ion concentration can allow this. Therefore the water movement is controlled by pumping ions such as sodium and potassium across call membranes. Because these things indirectly are controlled by things such as sodium, the excretion of it is usually followed by water. From this it can be concluded that water loss can be regulated by hormones that
control the rate of sodium excretion or the water permeability of the excretory ducts. (Kenneth S.Saladin, ©2012). Osmoregulation is usually achieved due to the disposal of metabolic wastes.
“The homeostatic control of water can be:
· a change in water concentration which activates negative feedback control
· osmoreceptors that are capable of detecting water concentration situated next to the circulatory system on the hypothalamus
· chemical messages sent from the hypothalamus to the pituitary gland
· pituitary gland secretes anti-diuretic hormone
(ADH), targets kidney responsible for maintaining water levels
·
hormone reaches tissue target, it alters the tubules of the kidney to become
less/more permeable to water
· if more required in the blood stream,
high concentrations of ADH make tubules more permeable
· if less
water id required in the blood stream, low concentrations of ADH make the
tubules less permeable”
(Homeostasis of Organism Water Regulation, updated 1 Jan 2000)
Example below:
water weight, so it is essential that it is kept under control (Kenneth S.Saladin, ©2012). Water is lost due to things like evaporation, excretion.
Because water cannot be transported through cell membranes, a change in the ion concentration can allow this. Therefore the water movement is controlled by pumping ions such as sodium and potassium across call membranes. Because these things indirectly are controlled by things such as sodium, the excretion of it is usually followed by water. From this it can be concluded that water loss can be regulated by hormones that
control the rate of sodium excretion or the water permeability of the excretory ducts. (Kenneth S.Saladin, ©2012). Osmoregulation is usually achieved due to the disposal of metabolic wastes.
“The homeostatic control of water can be:
· a change in water concentration which activates negative feedback control
· osmoreceptors that are capable of detecting water concentration situated next to the circulatory system on the hypothalamus
· chemical messages sent from the hypothalamus to the pituitary gland
· pituitary gland secretes anti-diuretic hormone
(ADH), targets kidney responsible for maintaining water levels
·
hormone reaches tissue target, it alters the tubules of the kidney to become
less/more permeable to water
· if more required in the blood stream,
high concentrations of ADH make tubules more permeable
· if less
water id required in the blood stream, low concentrations of ADH make the
tubules less permeable”
(Homeostasis of Organism Water Regulation, updated 1 Jan 2000)
Example below:
1. Dehydration
When the hypothalamus detects low levels of water in the blood (negative feedback) ADH will be secreted which sends a message to the kidney to make the urine more concentrated so not as much water is lost
2. Waterlogging
When the hypothalamus detects too much water in the blood, and the blood is too dilute, the calls absorb water via osmosis, causing them to be “waterlogged.” When in solution too dilute, cells become n danger of swelling and bursting, because of this it is important that the body uses homeostatic methods to correct itself so that the cells are not stressed because of waterlogging.
3.
Water gain
The three main ways your body gains water is by drinking, receiving the water content in food and tissue respiration. The hypothalamus detects that the blood is too concentrated, so the pituitary is stimulated to produce ADH stimulating the person to drink. The amount of water received from food depends what is eaten and how much. When cells respire glucose they produce water but the amount of water that comes from
that depends on how active the individual is.
4.
Water loss
Different ways that the human body can loss water is through exhaled air, evaporation through moist surfaces (like cornea), sweat, faces, lactation, vomit, spitting and urination. Every time humans breath out, water is lost, and it is something that can’t be controlled.
(Nigel D Purchon, ©1997-2012)
Random Fact: Human kidneys are around the size of the average human’s fist. The kidneys filter around 200 quarts of fluid. Approx. 2 quarts
leave body in the form of urine while the rest is retained in the body.
Process diagram below. BBC, ©2012
When the hypothalamus detects low levels of water in the blood (negative feedback) ADH will be secreted which sends a message to the kidney to make the urine more concentrated so not as much water is lost
2. Waterlogging
When the hypothalamus detects too much water in the blood, and the blood is too dilute, the calls absorb water via osmosis, causing them to be “waterlogged.” When in solution too dilute, cells become n danger of swelling and bursting, because of this it is important that the body uses homeostatic methods to correct itself so that the cells are not stressed because of waterlogging.
3.
Water gain
The three main ways your body gains water is by drinking, receiving the water content in food and tissue respiration. The hypothalamus detects that the blood is too concentrated, so the pituitary is stimulated to produce ADH stimulating the person to drink. The amount of water received from food depends what is eaten and how much. When cells respire glucose they produce water but the amount of water that comes from
that depends on how active the individual is.
4.
Water loss
Different ways that the human body can loss water is through exhaled air, evaporation through moist surfaces (like cornea), sweat, faces, lactation, vomit, spitting and urination. Every time humans breath out, water is lost, and it is something that can’t be controlled.
(Nigel D Purchon, ©1997-2012)
Random Fact: Human kidneys are around the size of the average human’s fist. The kidneys filter around 200 quarts of fluid. Approx. 2 quarts
leave body in the form of urine while the rest is retained in the body.
Process diagram below. BBC, ©2012