Do these chakras are real?

[Noah]

Hi

I'm a regular yoga practitioner and want to know about the chakras in yoga, my yoga teacher always talk about them, I've always seen them as a symbolic or a convenient way to assist teaching the pose, e.g. open your heart Chakra, which means lift your chest; contract Udiayana banda in plank, which means tighten your diaphram; lift mula banda, which means kiegal exercise.
I just want to know do these chakras are real? Do they correspond to nerve centers? Is there a general spiritual significance?


Thanks
Noah