Lungs

Yes, however it is very minimal, non-threatening, and it only happens after a period of time.

primary

There are no normally resident bacteria or viruses

There is no such thing as ten steps to cancer.

backward movement of epiglotis

The Mediastinum.

The autonomic nervous system. It runs automatically as opposed to thinking about doing something, it just does it on its own. If we had to think about breathing all day long, that would be very tiring.

Yes, a narwhal is a whale and whales are mammals, therefore a narwhal has lungs

Secondary lung cancer is cancer that starts somewhere else in the body (for example, the breast or colon) and spreads to the lungs.

There are 5 lobes in the lungs 3 on the right 2 on the left.

No, the eyes and lungs are not parts of the excretory system. The excretory system primarily consists of organs responsible for the removal of waste products from the body, such as the kidneys, ureters, bladder, and urethra. The eyes are part of the visual system, while the lungs are part of the respiratory system, involved in gas exchange rather than waste elimination.

Hm. There is no such thing as the "hilum of the upper lung". The hilum (also called the hilus) is the part of the lung where the bronchi, pulmonary veins, and pulmonary arteries enter the lung. Each lung has its own hilum. Surrounding the hilum are lymph nodes that help drain fluid that has entered the lung.

Since the hilum consists of so many different structures with distinct purposes, there's no easy way to discuss how the hilum "works". It's more of an anatomical entity rather than a functional one.

Do you have a specific question about the function of one of the structures in the hilum?

Pneumonoultramicroscopicsilicovolcanoconiosis

A primary bronchus is the first branch off the trachea, further branching leads to the secondary bronchus and then tertiary as you get deeper into the lung.

Mainly 2 but in extreme cases one person could have 3. For example in the Guinness book of records it states that a boy was born with a tail.But if a person were to have 3 lungs only 2 would wor.

Bicarbonate Ions

i think it is 100cm

The astronauts breath as they have an oxygen tank which they keep attached with their space suit.

In high elevation, mountainous areas, the air is very thin, meaning the oxygen molecules are more spread out. When people began living in these mountains, breathing was obviously an issue, since there was less oxygen to breathe. These people's bodies have adapted over the years, and they generally require less oxygen. Their body produces more red blood cells to carry oxygen as well.

No...If there are scar on the lungs...your resident visa will be rejected. My visa was rejected in December 2011 due to lung scars...

When did the currencies of Mozambique first come in circulation

Tar causes cancer because it contains a number of harmful chemicals and hazardous gases that are very bad for the environment. It is especially bad for children.

aeronautics

You may have Peyronies. Google for more info, but there seem to be treatment options you could explore.