Dinosaur necks

For dinosaurs, as with other animals, the neck was a vital channel between the head and the body.
Food passed from the mouth to the stomach
through the neck ; air was fed along the windpipe between the nostrils and lungs;never carried messages to and from the brain body, blood traveled through arteries and veins.
All of these lifelines, was as well as powerful muscles,were supported on the frame-work of neck vertebrate (Neck bones).

Barosaurus Neck vertobra 

Add caption

Long AND Flexible:

Herbivorous long-necked dinosaurs like barosaurus probably  used their flexible necks for cropping leaves from a large area of low-lying foliage while standing still. But if they needed to, they could have reached up to the leaves in tall trees.

Brosaurus's neck was 30ft (9.1 m) long.

Strong and light:

The long neck of Diplodocus was made up of 15 vertebrae. These bones had deep hollow inside them lightweight,although they remained very strong. A notch on of each vertebra carried a strong ligament, which support the neck in the way that wires support a suspension bridge. 

Short and stout:

Allosaurus , a fierce and terrifying carnivore, had a short and stout neck.

The neck bones were cupped tightly together to give a very mobile and curved neck. When Allosaurus.s jaws bit into prey, powerful neck muscles pulled the massive head up and back, tearing chunks of flesh from victim.

Like an Ostrich:

Gallimimus held its head high above its shoulders, like an ostrich. In this position, Gallimimus could swivel its head on its long neck to give good vision in directions.

Head Support :

Triceratops had an extension at the back of its skull made of solid bones. This made the skull very heavy.A short and very strong neck was needed to support the huge weight.