Those with advanced training and certification, such as the CPN credential, may also receive higher compensation. RNâs that go on to become Advanced Practice Registered Nurses (APRNs), including Pediatric Nurse Practitioners (PNPs), can also expect higher salaries.
CELLS: The most common connective tissue cells are: 1  Fibroblasts, which secrete collagen and other elements of the extracellular matrix. 2  Adipocytes, which store fat. 3  Mast cells, macrophages, and lymphocytes, cells with immune function which participate in inflammation.
One of the most predominant proteins is called collagen. Collagen is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content. An atomic-force-microscopy image of collagen fibrils in a collagen fiber.