Homeostasis unit1a biology

Homeostasis

Homeostasis means keeping the conditions inside the body constant. Conditions include temperature, blood suagar, water and carbon dioxide. Having a 'constant internal environment'.

The body temperature is normally 37 degrees Celcius if the temperature drops or rises by 3 degrees you will become ill.

Homeostasis is maintaining a constant internal environment

Conditions in your body need to be kept steady so that cells can function properly. This involves balancing imputs with outputs.

• levels of CO2 - respiration in cells constantly produces CO2, which you need to get rid of
• Levels of oxygen - you need to replace the oxygen that your cells use up in respiration
• Water content - you need to keep a balance between the water you gain in drink, food and from respiration and the water you lose by pee, sweat and when breathing out.
• Body Temperature - you need to get rid of excess body heat when you are hot but retain heat when the environment is cold.
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Water is Lost from the Body in Various Ways

Water is taken into the body as food and drink and is lost from the body:
-- through the skin and sweat
-- via the lungs in breath
-- via the kidneys in urine

On  a cold day or when you are not exercising, you don't exercise as much so you'll produce more urine, which will be pale.
On a hot day or when you are exercising you are sweating a lot so you will produce less urine but this will be concerntrated ( a deeper colour). You will also lose more water through breathing when you exercise becuase you breathe faster.

Negative Feedback Helps things Steady

Changes in…