Reference Article

from Wikipedia, the free encyclopedia

Nose

Anatomically, a nose is a protuberance in vertebrates that houses the nostrils, or nares, which admit and expel air for respiration.

In most mammals, it also houses the nosehairs, which catch airborne particles and prevent them from reaching the lungs.

Within and behind the nose is the olfactory mucosa and the sinuses.

Behind the nasal cavity, air next passes through the pharynx, shared with the digestive system, and then into the rest of the respiratory system.

In humans, the nose is located centrally on the face; on most other mammals, it is on the upper tip of the snout.

As an interface between the body and the external world, the nose and associated structures frequently perform additional functions concerned with conditioning entering air (for instance, by warming and/or humidifying it) and by mostly reclaiming moisture from the air before it is exhaled (as occurs most efficiently in camels).

In most mammals, the nose is the primary organ for smelling.

As the animal sniffs, the air flows through the nose and over structures called turbinates in the nasal cavity.

The turbulence caused by this disruption slows the air and directs it toward the olfactory epithelium.

At the surface of the olfactory epithelium, odor molecules carried by the air contact olfactory receptor neurons which transduce the features of the molecule into electrical impulses in the brain.

In cetaceans, the nose has been reduced to the nostrils, which have migrated to the top of the head, producing a more streamlined body shape and the ability to breathe while mostly submerged.

Conversely, the elephant's nose has become elaborated into a long, muscular, manipulative organ called the trunk.

Note: This article excerpts material from the Wikipedia article "Nose", which is released under the GNU Free Documentation License.

See the following related content on ScienceDaily:


Related Stories


Share This



Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins