In this post, we will talk about the heat exhaustion and heartstroke in I/GCSE Biology. Let's get started! 😉

When we exercise

• Heat production and body temperature increase when in a race compared to when resting

In I/GCSE Biology, you should remember the reason why our body is kept at 37°C

Why is our body kept at 37°C?

Do you remember the topic regarding enzymes in I/GCSE Biology?

• Body = internal temperature of 37°C
• Temperature at which enzymes work best
• Enzymes ➡️ speed up chemical reactions in the body
• Slow chemical reactions if body under 37°C, even slower if above
• Enzymes change structure and stop working if temperature above 45°C

• Homeostasis ➡️ process of keeping things constant & balanced in body
• Salts (sodium chloride) needed to help body work properly
• Na and Cl levels in blood controlled by kidneys (lost when sweating)
• Need balance of ion and water levels (sports drinks help replace these)

In I/GCSE Biology, it'd be better to memorize what heat exhaustion and heatstroke are!

• Both heat related conditions

Heat exhaustion – core temperature at 40°C

• water and salt levels drop

1. symptoms = nausea, heavy sweat.
2. When untreated = heatstroke
3. Taken to cool place + drink lots of water

Heatstroke – core temperature above 40°C.

• Cells break down & important parts of body stop working.

1. Symptoms = confusion, unconsciousness.
2. When untreated = multiple organ failure, brain damage, death
3. Cool core temp – ice packs / cold shower

Last but not least, let's talk about a little bit of osmoregulation in I/GCSE Biology!

• Loose water ➡️ urinate, pass faeces, sweat and air we breathe out (misty mirror when breathe on it)
• Kidneys control balance of water + ions in body.
• Do it by passing urine ➡️ contains excess salts + water + other waste materials (body doesn’t need these)

References:

1. "IGCSE Biology Notes:Understand that Homeostasis is the Maintenance of a Constant Internal Environment and that Body Water Content and Body Temperature are Both Examples of Homeostasis", https://lh4.googleusercontent.com/VYRNrV-j5X-gNcZ025SAbpgNIUR7yz1fz-6Uhm0YGP0w8W_6e_mUZs3vZtkyzgWE3vhTOtCgKRIRd_7DYPfEmBnpUbGyiUcTfXEWwb12-J6dfCw5VA6TLqNFv2GpThdiHIl36yft
2. "Heat-Related Illness in Children in an Era of Extreme Temperatures", https://pedsinreview.aappublications.org/content/pedsinreview/40/3/97/F1.large.jpg?width=800&height=600&carousel=1

3. ­­­"Biology Notes B1 Year 10". Document of I/GCSE Biology,

   https://getrevising.co.uk/resources/gcse-b1-notes

And we're done with this topic! Well Done!

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Drafted by Alyssa (Biology)