What is a nose?
A: A nose is a protuberance in vertebrates that houses the nostrils, or
nares, which receive and expel air for respiration alongside the mouth.
What are behind the nose?
A: The olfactory mucosa and the sinuses.
Behind the nasal cavity, air next passes through the
pharynx, shared with the digestive system, and then into what?
A: The rest of the respiratory system.
In humans, the nose is located centrally on the face
and serves as a what?
A: An alternative respiratory passage especially during suckling for
infants.
The protruding nose that completely separate from the
mouth part is a characteristic found only in what?
A: Therian mammals.
It has been theorized that this unique mammalian nose
evolved from what?
A: The anterior part of the upper jaw of the reptilian-like ancestors (synapsids).
Acting as the first interface between the external
environment and an animal's delicate internal lungs, a nose does what?
A: Conditions incoming air, both as a function of thermal regulation and
filtration during respiration, as well as enabling the sensory perception of
smell.
Hair inside nostrils filter incoming air, as a first
line of defense against what?
A: Dust particles, smoke, and other potential obstructions that would
otherwise inhibit respiration, and as a kind of filter against airborne
illness.
In addition to acting as a filter, mucus produced
within the nose supplements the body's effort to do what?
A: To maintain temperature, as well as contributes moisture to integral
components of the respiratory system.
Capillary structures of the nose do what?
A: Warm and humidify air entering the body.
During exhalation, the capillaries then aid recovery of
some what?
A: Moisture, mostly as a function of thermal regulation.
The wet nose of dogs is useful for what?
A: The perception of direction.
The sensitive cold receptors in the skin detect the place where the nose is cooled the most and this is the direction a particular smell that the animal just picked up comes from.
In amphibians and lungfish, the nostrils open into
what?
A: Small sacs that, in turn, open into the forward roof of the mouth through
the choanae.
These sacs contain a small amount of what?
A: Olfactory epithelium, which, in the case of caecilians, also lines a
number of neighboring tentacles.
In reptiles, the nasal chamber is generally larger,
with the choanae located where?
A: Much further back in the roof of the mouth.
In crocodilians, the chamber is exceptionally long,
helping the animal to do what?
A: Breathe while partially submerged.
The reptilian nasal chamber is divided into what three
parts?
A: An anterior vestibule, the main olfactory chamber, and a posterior
nasopharynx.
The olfactory chamber is lined by what?
A: Olfactory epithelium on its upper surface and possesses a number of
turbinates to increase the sensory area.
Birds have a similar nose to what?
A: Reptiles, with the nostrils located at the upper rear part of the beak.
Since birds generally have a poor sense of smell, the
olfactory chamber is what?
A: Small, although it does contain three turbinates, which sometimes have a
complex structure similar to that of mammals.
In many birds, including doves and fowls, the nostrils
are covered by what?
A: A horny protective shield.