How many chakras are there?

I've heard as many as 160+ but there's a few we need to focus on?
Where do chakras get their origins? 

Is there different words for chakra?

It just depends what you consider a chakra or an energy center. There are major energy centers, within the body we have seven, those have two entry and exit points with the exception of the crown and the base.  then you have two above your head, and two below your feet.
Minor centers, two in your hands and two in your feet. Even smaller ones in your joints, knees and elbows.
There is no need to focus on any of those unless you what you are doing with the energy, you might move through those centers when focusing on them. Energies can easily "misplaced" somewhere in the body and do harm, or bring discomfort at least.

Well, a Chakra is an energy center from point A - Point B. We have millions of chakras throughout our body and around 32,000 chakras or energy points in our head alone. We have 7 major chakra Seals that are used for the enlightenment process. Most people know of them and the emotional influence that is either blocking or opening them.
Root
Sacral
Solar Plexus
Heart
Throat
3rd Eye
Crown
I will not get into the details of them, there is all kinds of information on each chakra and how to open them. What colors are associated, sounds, foods, etc...

We also have the prana tube that flows down our spine and could be considered a chakra as well.

We also have many other Chakra Seals outside of the physical body. They have yet to be discovered and normally when they are being lived in, the ascension process is happening at that moment. Before we get more information of the 8th, 9th, 10th, etc chakra seals. We first need to master the first 7 Seals.

If you ever have trouble opening a chakra of any kind. Just remember they are YOUR Chakras. So just tell them to open and they open. Very simple process. If you want an awesome experience with chakras, Feel them opening. Watch as the open (with inner sight). Listen to them open, they have a certain humming sound that they produce inside of the body.
Hope this helps. :)

Im not sure if my heart chakra is too opened or closed but i would like some info on just how to make my heart feel better and stronger.It dosent need physical stuff just more love......

I know that there are chakras above and below the body as well but to how many there are in the body I have no idea. I heard that we have one on each joint and that there are pockets of them in various places in the body that contain many more though I have not personally looked to verify this. Somethings with numbers I am not sure how they know or who came up with them. If I wanted to know I would consult an acupuncture chart or similar because they actually work with them and know what each one does and where they are located. At least the ones that they manipulate for their work, I would trust those charts more than others.