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EXPLAIN OSMOREGULATION IN KIDNEY.........MKS......     (8)

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EXPLAIN OSMOREGULATION IN KIDNEY.........MKS......     (8)

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a) osmoregulation is maintenance of water balance of blood/tissues;

b) loop of Henle creates hypertonic conditions in the medulla;

c) water reabsorbed as filtrate passes through collecting duct;

d) hypothalamus monitors/controls water balance/content of blood;

e) controls secretion of ADH by (posterior) pituitary gland;

f) ADH is released when blood too concentrated/too little water/hypertonic;

g) ADH makes the collecting duct more permeable to water;

h) due to more aquaporins;
more water reabsorbed (in response to ADH);

i) less water in urine/urine more concentrated/urine hypertonic;

j) no/less ADH when blood too dilute/too much water/hypotonic;

k) collecting duct less permeable/less water reabsorption/more water in urine;

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-Osmoregulation is the control of the water balance of cells in the body
-it involves two main key events: loop of henle establishing salt gradient in the medulla and ADH regulating the water reabsorption in the collecting duct

Loop of Henle
-the descending limb of the loop of Henle is permeable to water but not salts
-whereas the ascending limb is permeable to salts but not water
-therefore, as the loop descends into the medulla, the interstitial fluid becomes more salty and hypertonic
-the vasa recta blood network that surround the loop of Henle flows in the opposite direction to maintain the salt gradient

Water reabsorption
-after going through the loop of henle, the intracellular fluid enters the collecting duct from the distal convoluted tubule
-due to the hypertonic nature of the intracellular fluid, water molecules will be drawn out by osmosis
-the amount of water released from the collecting ducts to be retained by the body is controlled by anti-diuretic hormone or ADH
-during dehydration, adh is released thus increasing the permeability of the collecting duct to water, by upregulating production of aquaporins
-this results in more water molecules being reabsorbed back to the blood thus making urin to become more concentrated
-during overhydration, the opposite happens

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- Osmoregulation controls the water potential in blood and cytoplasm of living organism (a)
- It takes place in 2 parts of the nephron,
-  the loop of Henle which controls the salt concentration and water reabsorbtion
- descending limb is impermeable to salts but permeable to water
- the water reabsorbtion takes place in collecting duct (c)
- amount of water reabsorbed controlled by ADH hormone that is secreted in the pituitary glands (e)
- depending on the state of the organism, the amount of ADH secreted will differ
- if the organism is dehydrated(f), more ADH is secreted the cells of the collecting duct becomes more permeable to water (g)as more aquaporines are produced(h)
- making the urine more concentrated (i)

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a) Osmoregulation controls the water content in the blood and tissues.
b) Osmoregulation occurs in the loop of Henle which help to regulate the salt gradient in the medulla, which create a higher concentration of water in the medulla. (hypertonic)

The two parts of loop of henle can be either permeable to salt or water, the descending limb is permeable to water and impermeable to salt, whereas the ascending limb is permeable to salt and not water.
Which causes the concentration of salt to increase when the loop of henle is descending towards the medulla, which create a salt gradient.

c) Water reabsorption then occurs in the collecting duct, since the medulla is hypertonic, water will be drawn towards the medulla, the amount of water will be controlled by the hormone ADH. (f) The ADH help to control water absorption when the body is dehydrated or suitably hydrated.

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a) Osmoregulation is the maintenance of water balance within the blood.

Osmoragulation occurs in the medulla of the kidney, within the loop of henle in the nephrons of kidneys

b) the loop of henle establishes a salt gradient between the vasa recta and the loop.

Counter currents between the loop of henle and the vesa recta capiliaries allow the salt gradient to be established since the water and salt cannot diffuse back and forth between the loop and the vesa recta.

The loop of henle is composed of a descending limb which is permeable to water but not to salt, and an ascending limb which is permeable to salt but not water.

c) The salt gradient established, allows water to be reabsorbed back into the blood from the descending limb into the vesa recta capilaries. This also results in salt being reabsorbed in the ascending limb.

i) and j) Once the salt has been reabsorbed, the filtrate then moves through the distal convoluted tubule, which carries out further selective reabsorption. However at this stage the filtrate contains less water an salt.

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Osmoregulation occurs in Loop of Henle and the collecting duct.

Loop of Henle
-Descending limb is highly permeable to water but not sodium ions
-Ascending limb is highly permeable to sodium ions but not permeable to water
-Creates osmotic pressure between nephron and medulla

Collecting duct
-Dehydration causes increase in ADH released by pituitary gland (f)
-Number of aquaporines increases (h)
-Encourages higher water reabsorption (c)
-Urine is hence concentrated and small in volume (i)
-Converse is true when the body is overhydrated
-Countercurrent maintains concentration gradient

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1) Osmoregulation occurs in the medulla, involving the loop of henle and collecting duct.
2)It controls the water balance of the blood. (a)
3)The loop of henle creates a salt concentration in the medulla (b)
4) Ascending limb is permeable to salt but not water
5) Descending limb is permeable to water but not salt
6) Loop descending into the medulla becomes saltier and thus hypertonic (b)
7) In the opposite direction there's the vasa recta blood network surrounding the loop of henle which is called countercurrent
6) Salts released from ascending limb thus enters the medulla creating a further salt gradient
7) The collecting duct passes through the medulla and the hypertonic solutions in the medulla (due to limb descending into medulla) draws water out by osmosis (c)
8) ADH is a hormone released from  the pituitary gland in the hypothalamus, which controls water balance (d+e)
9) It controls the amount of water absorbed out through osmosis (e)
10) It also increases the permeability of the collecting duct to water (g)
11) When dehydration occurs, ADH increases so that less water is remaining in the urine to be passed out, so urine is more concentrated (f + h)

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osmoregulation  happens in loop of henle and collecting duct. b

loop of henle create concentrated salt gradient in medulla.

loop of henle consisted descending limb and ascending limb

descending limb is permeable to water but not salt

water comes out from descending limb,

the concentration gradient in descending limb increases.

ascending limb is permeable to salt but not water

salt comes out from ascending limb

the concentration gradient in ascending limb decreases.

in collecting duct, water is reabsorbed by osmosis. c

the reabsorption is controlled by hormone called ADH

when the person is experienced dehydrated, pituitary gland will release ADH e f

when the level of ADH increases, the water channel on collecting
duct is open g

more water is absorbed  h
vice versa

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"Explain Osmoregulation"

Osmoregulation is the process by which there is a control of water balance in the blood of the organism. (a)

Osmoregulation occurs in the medulla of the kidney which involves the Loop of Henle and the collecting duct.

The Loop of Henle's function is to create a high solute concentration in the tissue fluid of the medulla. (b)

The descending limb of the Loop of Henle is permeable to water but not to salts.

The ascending limb of the Loop of Henle is permeable to salts but not to water.

The vasa recta network of capillaries that are present around the Loop of Henle flow in an opposite direction (this is known as counter current). This allows a salt gradient to be formed.

As the collecting duct passes through the medulla, the high solute potential (hypertonic) condition will draw water out via osmosis. (c)

The amount of water which is retained by the body is controlled by a hormone known as ADH (anti-diuretic hormone) which is released by the posterior pituitary that is present in the brain. (e)

When our bodies are dehydrated, the ADH is released which increases the permeability of the collecting duct to water by causing there to be a higher production of pores (aquaporins). (f) & (g)

Therefore less water is present in the filtrate and the urine of the person will be more concentrated with urea and salts (therefore they will urinate less) (h)

# data[].attributes.body
- Osmoregulation is the maintenance of water balance of blood/ tissues (a)
- The loop of Henle and collecting duct are involved in osmoregulation

- An osmolarity gradient is created between the nephron and the medulla (b)

- Descending limb of the loop is permeable to water, but not sodium ions, vice versa for the ascending limb
- The ascending limb pumps out sodium ions into the medulla, creating the osmolarity gradient
- Water then leaves the descending limb through osmosis
- After ultrafiltration, the filtered blood enters the collecting duct (c)
- Water moves from the collecting duct through osmosis, and the counter-current mechanism
- The blood flows in the opposite direction of the loop of Henle, maintaining the gradient

Dehydration
- When the body feels dehydrated, ADH is released by the pituitary gland (f)
- ADH causes the opening the water channels in the collecting duct (g)
- More water can be transferred into the blood, leading to urine being more hypertonic (i)

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Osmor

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Osmoregulation is a process where it retains water in the kidney. It takes place in the Loop of Henle and Collecting duct.
There is two different sections in the loop of henle.

Ascending loop of henle
-permeable to Na+ but not water
-Na+ is pumped out of the ascending limb into the medulla
-this generates an high water potential so as to allow water to diffuse into the blood.

Descending loop of henle.
-permeable to water but not Na+

Collecting duct
-filtrate enters collecting duct from distal convoluted tube
-countercurrent flow of blood  in the capillaries and filtrate the duct
-this maintains the concentration gradient so as to  allow osmosis to the blood
-when we are dehydrated, ADH is released(h)
-this causes the aquaporins to open in the walls of duct.(h)
-therefore more water will enter the blood (c)
-excess water in blood leads to break down of aquaporins and hypotonic urine. (i)

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Osmoregulation is important in maintaining optimal solute concentration in the body for metabolic activities.
The organ involved in osmoregulation is the kidney which comprises of the medulla and cortex containing nephrons.

- The collecting duct is the section of the nephron responsible for osmoregulation.
- When the solute concentration of the blood is high, ADH, a hormone for the formation of aquaporins (h), is secreted by the pituitary gland (e, f)
- This causes the collecting duct to be more permeable to water (g), causing more water in the filtrate to be reabsorbed.
- As a result, a small volume of concentrated urine will be produced while the blood has a lower solute concentration (more dilute)(i)

- When the solute concentration is too low, ADH is not secreted (j)
- This causes the collecting duct to be less permeable to water, leading to a reduction in the number of aquaporins and less water to be reabsorbed.
- As a result, a larger volume of diluted urine is produced, causing the solute concentration in the blood to be higher. (k)

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Osmoregulation is a process to maintain water balance of blood., tissue and cytoplasm of a living organism. (a)
The loop of Henle is consisted of a descending limb and an ascending limb.
The ascending limb is permeable to salt. Active transport of salt generate a concentration gradient in PCT cells.
(b)
The descending limb is permeable to water. Water moves into the PCT cell from region of lower solute concentration to region with higher solute concentration by osmosis.

The water and salt in PCT cell is removed by blood flow in vesta recta, blood capillaries that runs along the loop of Henle.
Blood in vesta recta flows in opposite direction compare to the flow of substance in loop of Henle in a counter current mechanism to maintain a concentration gradient.

When a person is dehydrated, pituitary gland in brain releases ADH (e) (f) that promotes the formation of aquaporins in collecting ducts. Permeability to water increases.(g)
More water moves into the peritubular  capillaries by osmosis.(h)
Urine becomes more concentrated. volume of urine excreted decreases. Water is preserved. (i)
When the person gets suitably hydrated, pituitary gland stop secreting ADH. (j)
Less aquaporins forms and less water move from collecting duct to peritubular capillaries by osmosis.
Less water is reabsorbed.