THE NOSE IN INDIA
The outer portion of the nose is the part you can see. It is made from cartilage, a soft rubbery tissue that gives it its shape; it’s attached to your skull at the nasal bone. Inside, the nose is divided into two cavities, leading from each nostril, which are separated by another strip of cartilage called the septum. In the diagram at the right, you can see one of these cavities, leading into the head. The inner nasal cavity is also connected to other cavities called sinuses.
The nostrils are lined with stiff hairs that keep dust, dirt, microorganisms, and even small insects from being breathed into your lungs. The larger inner nasal cavity is very deep, and connects to your airway, and to your inner ear via the eustachian tubes. There are mucous membranes within the nose, which secrete a thick mucous that also helps trap dirt. At the top of the inner cavity is the olfactory bulb, which contains the receptors that collect molecules and help you smell.
The sinuses are cavities in your head. The sinuses are lined with a mucous membrane … soft, moist tissue covered with a layer of mucous. The tissue is also covered with microscopic hairs called cilia. The cilia wave back and forth, moving the mucous into the nasal cavity where it can capture dust, dirt, microorganisms, and pollen. The dirt-laden mucous is then flushed out to the stomach via the back of the throat. This is the way your body prevents bacteria from entering the body when breathing through the nose.
Smell
In order for you to smell something, molecules from the thing you’re smelling have toenter your nose. Everything you smell, therefore, is giving off molecules. Those molecules are usually small, easy to evaporate chemicals that float through the air into your nose. A piece of metal has no smell because nothing evaporates from it. These molecules floating into your nose are called odorants. They stimulate sensory nerve cells (neurons) in the olfactory bulb called receptors, which send electrical impulses to the brain.
The olfactory bulb contains other receptors called trigeminal nerve receptors. The trigeminal nerve (which is the largest cranial nerve, connecting the face, teeth, and mouth to the brain) provides a second set of nerve endings which are responsible for touch, pressure, pain and temperature sensations in the mouth, eyes and nasal cavity.
Certain chemicals produce effects described as hot, cold, tingling or irritating when detected by the trigeminal nerve. For example, menthol produces the feeling of cold (or hot, in high concentrations); the chemicals capsiacin in hot chili peppers and diallyl sulfide in onions also stimulate this nerve.
Human beings have a very weak sense of smell, and it doesn’t always work well. When we have a cold, excess mucous blocks the receptor cells, and we have trouble smelling. When we smell the same odour for too long, the receptor cells get ‘tired’, and stop sending signals to the brain, so we stop smelling the persistent odour.
Followings Are The Nose Conditions :
- Hay Fever
- Nasal Cancer
- Nose Disorders
- Sinusitis
- Taste and Smell Disorders
