What makes odors

They are constantly moving and eventually they spread out through the air around them. Once the odour particles enter our nostrils they are detected by olfactory receptors near the back of our nose.

These receptors then send signals to an area of the brain called the olfactory bulb and the chemical composition of the mix of odours it determined. What is really interesting is that the smell detection pathway within the brain also connects to the amygdala and hippocampus, areas connected with emotion and memory. Smells can literally change how we feel or help us make connections and lay down memories.

Some people have no sense of smell, or they lose it during their lifetime. This is called anosmia. When we lose our sense of smell it can have a big impact on our psychological wellbeing. A large portion of the human genome is taken up with the olfactory receptor gene family.

That is quite an incredible fact. For a sense that has often been dismissed, we have actually vested a lot of our genetic code in it. Not so surprising when we consider that it is usually our first line of defence.

Olfactory receptors were once thought to be localised to a small area within the nose, but in recent years they have been detected all over the body; from muscles, kidneys, liver, lungs and even blood vessels.

Why do we need to smell things inside our bodies? Perhaps these receptors have a basic function to play in many parts of the body. Olfactory receptors are sensitive chemical receptors; they detect changes in chemical concentrations. It is likely that they act in a similar manner in other parts of the body, detecting the presence of certain chemicals, or the changes in their concentrations. Olfactory receptors have even been found in human sperm.

Volatilized chemical compounds, many of which are produced by bacteria source. Gross, right? Bacteria emit foul-smelling gaseous molecules that our noses discover. Some smells are extremely pungent, while others are subtle and barely noticeable. In addition, some people are very sensitive to smells, while others find it difficult to smell things. Your age, sex, and whether or not you smoke can all affect your ability to smell.

Because bacteria are responsible for odors, you must locate the source of an odor and eliminate it if you wish to make the space smell more pleasant. However, sometimes a mysterious odor will crop up and confuse you. Use the following tips to find those baffling, offensive odors:. Remember that different odors can indicate different causes because bacteria have unique volatile traces.

What could be causing the odorous scents in your home? Here are some common culprits:. Identifying a smell or determining its cause can affect the health and safety of the people in the vicinity. Most people who develop a smell disorder have experienced a recent illness or injury. Common causes of smell disorders are:. Both smell and taste disorders are treated by an otolaryngologist , a doctor who specializes in diseases of the ear, nose, throat, head, and neck sometimes called an ENT.

An accurate assessment of a smell disorder will include, among other things, a physical examination of the ears, nose, and throat; a review of your health history, such as exposure to toxic chemicals or injury; and a smell test supervised by a health care professional.

There are two common ways to test smell. Some tests are designed to measure the smallest amount of odor that someone can detect. Another common test consists of a paper booklet of pages that contain tiny beads filled with specific odors. People are asked to scratch each page and identify the odor.

Diagnosis by a doctor is important to identify and treat the underlying cause of a potential smell disorder. If your problem is caused by medications, talk to your doctor to see if lowering the dosage or changing the medicine could reduce its effect on your sense of smell.

If nasal obstructions such as polyps are restricting the airflow in your nose, you might need surgery to remove them and restore your sense of smell. Some people recover their ability to smell when they recover from the illness causing their loss of smell. Some people recover their sense of smell spontaneously, for no obvious reason. Like all of your senses, your sense of smell plays an important part in your life. Your sense of smell often serves as a first warning signal, alerting you to the smoke of a fire, spoiled food, or the odor of a natural gas leak or dangerous fumes.

When their smell is impaired, some people change their eating habits. Some may eat too little and lose weight while others may eat too much and gain weight. As food becomes less enjoyable, you might use too much salt to improve the taste.

This can be a problem if you have or are at risk for certain medical conditions, such high blood pressure or kidney disease. In severe cases, loss of smell can lead to depression. Problems with your chemical senses may be a sign of other serious health conditions.

It can also be related to other medical conditions, such as obesity, diabetes, hypertension, and malnutrition. If you are experiencing a smell disorder, talk with your doctor. The NIDCD supports basic and clinical research of smell and taste disorders at its laboratories in Bethesda, Maryland, and at universities and chemosensory research centers across the country.

These chemosensory scientists are exploring how to:. The NIDCD maintains a directory of organizations that provide information on the normal and disordered processes of hearing, balance, taste, smell, voice, speech, and language.