Changes

===Insensible Water Loss===

===Insensible Water Loss===

Insensible water loss is water loss which cannot be sensed by the individual and tend to be a response to thermoregulation rather than being a regulated process of water homeostasis.  It includes evaporation from the skin and epithelial surfaces of the airways and varies with environmental temperature and humidity as well as air movement.  The main losses being from sweating and increased respiration.

'''Insensible water loss''' is water loss which cannot be sensed by the individual and tend to be a response to thermoregulation rather than being a regulated process of water homeostasis.  It includes evaporation from the skin and epithelial surfaces of the airways and varies with environmental temperature and humidity as well as air movement.  The main losses being from sweating and increased respiration.

===Water Loss Through the Faeces===

===Water Loss Through the Faeces===

===[[Aquaporins of the Kidney and Water Homeostasis - Anatomy & Physiology|Renal Regulation of Water Loss]]===

===[[Aquaporins of the Kidney and Water Homeostasis - Anatomy & Physiology|Renal Regulation of Water Loss]]===

Only the kidenys are capable of precise adjustment of water loss to compensate for the variation in water intake.  However a minimum amount must always be excreted to remove the waste.  For example of 70kg human produced 600mosmol of solutes every 24 hours even without food.  This is mainly Urea, Uric acid, phosphate, creatine, creatinine other waste products and ions.  In humans the maximum urine osmolarity is 1200mosmol/l therefore their is a minimum water loss of 500ml even when no food or water is available.  When this is added to another 500ml in the exhaled air and 400ml evaporated from the body surfaces a person loses 1400ml of water per 24 hours.  This is the inevitable water loss.  300ml of metabolic water is produced per 24 hours in this person leaving an 1100ml deficit to be compensated for by drinking.

Only the kidenys are capable of precise adjustment of water loss to compensate for the variation in water intake.  However a minimum amount must always be excreted to remove the waste.  For example of '''70kg human''' produced '''600mosmol''' of solutes every 24 hours even without food.  This is mainly Urea, Uric acid, phosphate, creatine, creatinine other waste products and ions.  In humans the maximum urine osmolarity is '''1200mosmol/l''' therefore their is a minimum water loss of '''500ml''' even when no food or water is available.  When this is added to another '''500ml in the exhaled air''' and '''400ml evaporated''' from the body surfaces a person loses 1400ml of water per 24 hours.  This is the '''inevitable water loss.''' '''300ml of metabolic water''' is produced per 24 hours in this person leaving an '''1100ml''' deficit to be compensated for by drinking.

===Water Intake and Lactation===

===Water Intake and Lactation===

Water intake during lactation increases significantly even over and aboce the requirement for milk.  To produce 31l of milk and cow needs to take an extra 57l of water.  This is thought to be because of an increased loss from the airways, skin and faeces.

Water intake during lactation increases significantly even over and aboce the requirement for milk.  To produce 31l of milk and cow needs to take an extra 57l of water.  This is thought to be because of an increased loss from the airways, skin and faeces.