Get category name from product page

Get the parent category

$_cat = new Mage_Catalog_Block_Navigation();
$curent_cat = $_cat->getCurrentCategory();
$curent_cat_id = $curent_cat->getId();
$parentId=Mage::getModel('catalog/category')->load($curent_cat_id)->getParentId();
$parent = Mage::getModel('catalog/category')->load($parentId);
$categorydaddy = $parent->getName();

Get the current category

    $categoryName = Mage::registry('current_category')->getName();
    foreach ($categoryName as $_category):
       $categoryName = $_category->getName();
    endforeach;