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Homeostasis
- The maintenance of a constant internal environment.
What are the main factors that are controlled?
In I/GCSE Biology, Internal conditions which are controlled include:
- The water content of the body.
- The ion content of the body.
- Blood sugar levels
Osmoregulation
- In I/GCSE Biology, The process of water movement into or out of cells is called osmosis.
- We take in waterand salts by drinking.
- We lose water by breathing, sweating, and urine production by the kidneys.
- We lose ions by sweating and urinating.
- The major control of water and ions is by our kidneys.
Blood sugar regulation🩸
- We take in sugar as carbohydrate in our food.
- We control blood sugar levels by releasing insulin (a hormone) from the pancreas.
- Our cells need a constant supply of blood sugar for energy.
Thermoregulation💦
- Temperature regulation.
- Enzymes work best at 37OC.
- Above and below this by a few degrees, and our cellular reactions stop working.
- We control our body temperature using our skin, eg by sweating.
Sports Drinks🍹
Contain salts (sodium and potassium ions), glucose and water.
Isotonic sports drinks
- The same concentration of ions as the body fluids
- Enables rapid uptake of glucose
Hypotonic sports drinks
- Lower concentration of ions than in body fluids.
- Enables rapid uptake of water by osmosis.
Hypertonic solutions – not in sports drinks
- Higher concentration of ions than in body fluids
- Water is drawn into the gut – this dehydrates you - not sensible in a sports drink!
That's the end of the topic!
Drafted by Joey (Biology)
Reference:
https://getrevising.co.uk/resources/biology_revision_notes4