Textures in texture packs Minecraft?

Hello everybody,

I'm currently doing a lot of Minecraft texture packs. There's now this file at icons -> gui, on which the hearts and hunger clubs etc. Are displayed. But there are some things that I don't understand. They are circled in the picture. Does anyone know what that is?

The white hunger bars are the empty hunger bars.

Hi these are animation textures. For example, if you lose your life then your hearts will flicker before turning black. And the rest are the animations for potion effects. If that is difficult to change, just take a file from another TP and just change the main hearts and the appropriate animation. This is a helpful video if you can speak English halfway.