Do internal liks count as backlink

i have many interanl links and also links from those pages back to my home page however these are not counted by any of the search engies as a link. Anybody know why ? Also do these internal links count towards the page rank ?

Yes they do. There's two types of backlinks. Internal and External. Internal links are still important, however they're not weighed anywhere near as heavily as external links. Internal links are primarily so the search engine can figure out which pages are important to YOU on your site.

External links are so that search engines can see what pages on your site other people feel are important.

As far as internal backlinks counting towards pagerank, yes they do, to a degree. They won't help you much though unless you've got hundreds of thousands of pages indexed.