The Basics of Nerve Fibres

• Nerve fibres look like circles in a cross-section.
• They have a plasma membrane that wraps around some gooey stuff called cytoplasm.
• In us humans, these fibres are about the width of a hair (1µm). Imagine that!

Bigger Fibres, Faster Messages

• Some cool animals like squids have jumbo nerve fibres (up to 500µm wide). Why? To send messages fast!
• Think of it this way: a wide highway can handle more cars speeding by than a narrow alley.
• Fun fact: When squids feel threatened, they use these giant axons to power up a super speedy escape move—jet-propulsion style! 🚀🦑

Not All Animals Go Big

• Animals can't just grow a bunch of these giant fibres. Space and resources are limited.
• Earthworms, for instance, are like, "Three giant axons are enough for me, thanks!" They use them to dash away from hungry predators.

Boosting Speed with Myelination

• Myelination is like adding express lanes to our nerve fibre highways.
• The nerve fibres get this snazzy coat made of Schwann cells. There are tiny gaps in this coat called nodes of Ranvier.
• Nerve impulses play hopscotch, jumping from one node to the next, making them SUPER fast, like up to 100 metres in a second!

Understanding Correlation

• Ever heard someone say, "Oh, these two things are related"? That's correlation!
• It tells how two variables move in relation to each other. They can move in the same direction (positive) or opposite (negative). The relationship can be strong, weak, or somewhere in between.

Say Hello to 'r'

• 'r' or the correlation coefficient tells us how strong a correlation is.
• Close to 1 (or -1) = Strong correlation. Close to 0 = Weak correlation.

Coefficient of Determination (R²)

• It's a fancy way to see how well our data fits a trend.
• If R² is 0.1523, it means only 15% of our data is close to the best fit line.
• Perfect fit? R² would be a solid 1.