Here are some good links to help.
Bird anatomy - Wikipedia, the free encyclopedia
Bird Anatomy

This article is not intended to be a complete thesis on the care of pigeons in all circumstances or times. It is merely designed as something to answer a beginner's basic questions to keeping pigeons alive and healthy. There are many pathways to the same end, but, all have similar building blocks. I have purposely not added lots of pics and links to this article to make it more printer friendly for you.

ALL pigeons, regardless of breed, have certain needs. These include food, water, and shelter. The type of shelter would depend on your local environmental conditions. Someone who lives in Alaska or northern Canada is going to need a different loft (coop) arrangement than is someone who lives in Hawaii or southern California. Someone who breeds Runts (Romans), which are the largest of all domestic pigeons, weighing in at up to 3 lbs (1.5 kg) will need more space per bird and larger nest boxes than will a breeder, who is raising Figuritas, which weigh about 6 oz. (160 g.). If you have a heavily muffed (feather-footed) breed, you will need different perching arrangements than you would if you raised a clean-legged breed.
The full reading here
Care of Domestic Pigeons(Columba livia)

It's sad to think that one day, the planet Earth may be gone. This is despite our best efforts to save her. The good news is that provided we all work together, we can preserve the status quo on our beautiful blue world, for centuries to come. Provided that is we heed the warnings nature is sending us, such as global warming and other pollutions.
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BIRDS

The Beak. Because a bird's beak is a critical part of its everyday functioning, problems with the beak need to be addressed immediately. "Beak rot" (psittacine beak and feather disease) may cause the beak to crack. An infestation of mites or poor nutrition can lead to beak problems, as can injury. The lack of normal wear can cause the beak to "over-grow". Provide your bird with products that promote beak health, keep the cage clean, and watch for scaling (mites).

Also, watch for changes in the "cere" (located at the base of the upper beak). A disorder called "Brown Hypertrophy" affects this area. It is not critical unless it begins to block the nasal passage. It is displayed as a thickening to this area; brown in color.

Bleeding. Birds have very small volumes of blood so any bleeding should be immediately treated. If the bleeding is from a cut or other injury apply pressure directly to the bleeding area. Then clean the area of the wound, but do not probe. Bleeding in the beak or toe nails can be treated with a styptic powder, corn starch or baking power and pressure. A bleeding, broken feather is probably the most common mishap, and should be completely removed and pressure applied. Use two people, one to hold the bird and the other to pull the feather -- use a pliers if necessary. Be very careful not be break any bones or a wing. If the bleeding continues, or the wound is serious, get to the vet.

Breathing. Changes in your bird's breathing patterns, sneezing, runny nose, lack of appetite, and decreased vocalization can all be signs of respiratory infections. Lack of Vitamin A, drafts, stress, and changes in the ambient temperature are prominent causes. It could be just a common cold or sinusitis (also indicated by swelling under the eyes), pneumonia, inflammation of the air sacs; or, it could be symptoms of psittacosis or Newcastle disease.

Colds. He sounds like he's got a "code in da node." While your polite "God bless you" to your bird's soft sneeze may be nice, you also need to be alert for serious complications. A runny nose usually means an infection, or irritation of the respiratory system, and when accompanied by other abnormalities it can suggest a serious infection. See your vet.

Coordination If your bird becomes confused, unstable or uncoordinated see your vet immediately. Causes can be head trauma that may clear itself in a couple of hours; or it could be suffering from lead poisoning, infections, tumors, or more serious head trauma. Take no chances - go to the vet.
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Your bird's health care

Avian respiratory system.
The avian respiratory system delivers oxygen from the air to the tissues and also removes carbon dioxide. In addition, the respiratory system plays an important role in thermoregulation (maintaining normal body temperature). The avian respiratory system is different from that of other vertebrates, with birds having relatively small lungs plus nine air sacs that play an important role in respiration (but are not directly involved in the exchange of gases).
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Bird Respiratory System


The avian respiratory system: a unique model for studies of respiratory toxicosis and for monitoring air quality.
Here's the link
The avian respiratory system: a unique model for studies of respiratory toxicosis and for monitoring air quality.

RESPIRATION AND CIRCULATION
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Respiration and Circulation


Theropod dinosaurs and birds linked by 'breathing' design
The full article here.
Bird Lung

Avian Respiration figure
Avian Respiration figure

Avian Respiratory Physiology
Avian Respiratory Physiology

Compositions for treating avian respiratory diseases and methods of using same
Compositions for treating avian respiratory diseases and methods of using same - Patent 3268404

Thank you for the links I am slowly getting to them I have them marked on favorites. I found the one on anatomy really good. as I am the new owner of only budgies ( Cute mind you). its now nice to know some of the terminology...

Thanks Arty, lots of good information there!