The proper functioning of sensory organs is important. So, Keeping them in health is imperative. This article will give the information on the five sense organs, their functioning, and ways to keep them healthy.
Sensory organs are the biologically relevant organs that helps us identify different sensations in our day-to-day practices. The sensory organs transmit the signals to your brain and your brain, in turn, helps in interpreting the sensory signals.
The human body contains five sense organs, also known as sensory organs-
- Eyes- For the sense of sight,
- Nose- For the sense of smell,
- Skin- For feeling the sense of touch,
- Tongue- For determining the sense of taste,
- Ear- For the sense of hearing.
These sense organs constitute various sensory cells. These sensory cells react to certain specific types of stimuli. Sensory receptor cells transform the physical stimuli into the nerve signals that are further interpreted by your brain cells.
The Five Sense Organs and Their Functions
Five sensory organs form together to form the sensory system that helps you sense the five physical stimuli, namely:
- Eyes give the sense of sight,
- The tongue gives the sense of taste,
- The nose gives the sense of smell,
- Skin gives the sense of touch,
- Ears give the sense of hearing.
External stimuli induce capacitance in the sensory organs and send these signals to your brain through the sensory nerve. Your brain will in turn respond to these signals/messages, and help your sense organs to reciprocate in response to the stimuli. These responses help you to connect to your external environment.
EYES: Sense of Sight
The sense of perceiving things that we can see or watch in our daily lives is conducted by the eyes. The eyes are a composition of complexly organised sensory organs containing 256 unique features and accounting for 80% of our daily learnings. An eye can capture as many as 50+ images in only one millisecond.
The outer transparent layer covering the eye is called the cornea of the eye. It bends the light coming towards the eye and converges it to the eye lense. The eye has one more protective layer known as the iris that works like the shutter of a camera shutter. The light coming towards the eyes passes through the iris and goes through a small hole in the Pupil and reaches the cornea. The cornea focuses these light rays coming to pass them through the lens.
The light rays are eventually converged into the retina, this is done by the lenses. The retina is responsible for draining the signals to the nerve cells. The retina is the innermost layer of the eye.
But how do we see colours? The retina contains two types of cells having a rod and a cone-shaped cells. These rod and cone cells are responsible for translating these light signals into the colourful central vision that we possess. Rod cells or rod-shaped cells are also responsible for the limited light zones or the vision at night. The retina is responsible for transmitting the acquired light information into electrical impulses to the brain through the optic nerve.
Any impairment in the vision or your eye functioning can be caused due to certain eye conditions which might include diabetic retinopathy, cataracts, age-related macular degeneration, glaucoma (tumours), retinitis pigmentosa, and eye infections.
TONGUE: Sense of Taste
The tongue is another sense organ that helps us identify the taste of different foods. The sense of taste perceived by the tongue is subdivided into five different types of tastes:
- Sweet,
- Salty,
- Bitter,
- Sour,
- Umami or savoury.
We would think that feeling spicy is also a form of taste. But, spicy a sense of pain signal as described by the National Library of Medicine (NLM).
The tongue has numerous taste buds. A normal adult contains 2,000 to 4,000 taste buds on an average, these taste buds are lined up onto the tongue, on the epiglottis, at the back of your throat, in some parts of the oesophagus, and in the nasal cavity.
Sensory cells are present on the taste buds that have pores that function as funnels. The pores contain very small taste hairs on them. The chemical helps in the binding of the hair proteins with the cells, which eventually helps with the sense of taste.
We are also taught that the tongue has certain specific areas in it that are dedicated to perceiving certain tastes, although this is a myth. All the distinct flavours or tastes can be sensed by any of the tongue parts. However, it would be correct to say that their sensitivity level can differ in different parts.
Studies have shown and identified the relationship between the sense of taste and the sense of smell. the sense of smell can also be perceived by our mouth, this is known as olfactory referral. And so, we can correlate if we have a stuffy nose, our sense of taste is also altered.
The food texture which is felt through our other sense organ, the skin and visualised through another, the eyes, also contribute to the overall taste of something.
The cells of tongue that detect the flavour, known as the basal cells have regenerative properties. These cells can regenerate 10% of the cells every single day. This is why even if your tongue is burnt due to hot food items, your tongue’s sense of taste does not die but heals quickly.
These basal cells have receptors that help receive the stimuli of taste and then send the electrical signals to your brain. The taste receptors function and express through the chemosensory properties that they possess which helps us perceive the taste sense.
Being small enough of a sensory organ, the tongue can develop certain conditions including ageusia (loss of taste), oral thrush, or hypogeusia (limited taste sense).
NOSE: Sense of Smell
It is an interesting fact that every human being can sufficiently distinguish more than 1 trillion odours/smells. One research has shown that the olfactory cleft present on the roof of your nasal cavity can help determine smell with the help of the olfactory bulb and fossa. The olfactory cleft contains certain nerve endings which help in the transmission of the smell signals to the brain.
Neuroscientists say that humans possess more than 400 receptors of smell on their nasal cavity floor, these receptors help in the differentiation of different types of odours with similar effectiveness as that of dogs.
Age can compromise or decrease the ability of an individual to smell, this condition is also known as hypersomnia. Hypersomnia can be caused due to many underlying medical conditions, including sinusitis and common flu. Some chronic conditions including multiple sclerosis, schizophrenia, Parkinson's, and brain injury can also induce the loss in the ability to smell, this condition is also known as Anosmia.
SKIN: Sense of Touch
The largest sense organ in the human body is the skin. Skin is the most sensitive and natural defence system that protects against many external predators. According to one article, the sense of touch perceived through the skin is among the first senses that a human develops.
Some specialised neurons are present on the skin that help transmit different sensations including that of pressure, touch, vibration, pain, light touch, tingle, temperature and texture change to our brain.
Ageing or getting old can affect the health of your skin which impacts the touch sensation, this condition is known as hypoesthesia or reduced sensitivity to touch or loss of touch sensation.
EAR: Sense of hearing
A spiral organ present in your body at the lateral side of your head is known as the ear, which helps you to hear. This sensory organ that helps to hear contains three parts.
- The external ear
- The middle ear
- The inner ear
The external ear or the pinna collects the sound waves, these sound travels through your auditory canal and then reach the tympanic membrane or the eardrum present in the middle part of the ear. The eardrum is a connective tissue that is very thin and sheet-like, the eardrum vibrates when sound waves hit on it.
The sound keeps travelling through the ear and moves into the iner part of the ear containing three bones ( in middle ear).
These bones are
- malleus (hammer),
- incus (anvil),
- stapes (stirrup).
The sound travelling through the ear generates vibrations when they hit these tiny ear bones or the ear ossicles. These vibrations are then sent to the organ of the Corti. Tiny hair cells are present in the organ of Corti that translate these vibration signals into the electrical signals/impulses. These electrical signals travel and reaches the brain through the sensory nerves of the ear called auditory nerves.
Ears also maintain and modulate your balance sense. The middle ear helps your body to equalise the air pressure with the external atmosphere.
Hearing loss can occur due to various factors including ageing or any other medical condition. However, according to statistics hearing loss, in India, has become a common concern, that affects almost 63 million Indians, among which the elderly are the most common.
How to Keep the Sense Organs Healthy?
We have discussed and understood each of our 5 sensory organs, along with their understanding in distinct functions. We will now discuss the essential facts that will help us keep these sensory organs healthy and strong. The overall quality of life can be altered by any deterioration or dysfunction in any of the five sensory organs i.e. the eyes, the nose, the tongue, the ears, and the skin.
Loss of any sensory organ functioning can cause-
- Immobility chances become high
- Hampering in your day-to-day chores,
- Certain major health problems including mental problems,
- Can Impact the overall quality of health.
In short, if you do not take care of your senses, your health and quality of life cannot improve. Regular check-ups and appointments with your doctor can ensure good maintenance of your health. Remember, if you catch any disease or impairment early in its stages, the conditions will be limited and its effects eventually.
For Sight
Loss of eyesight, whether it is complete or partial, it can devastate you both mentally and physically. This can eventually impact your everyday activities and the quality of your life.
You should eat a nutritious and healthy diet:
Your eyes require a generous amount of Vitamin C, Omega-3 fatty acids, and vitamin E. Green leafy vegetables, citrus fruits, berries, nuts, fish, and seeds can be very helpful in maintaining your eyes health and functioning.
Monitor your blood pressure and blood sugar levels:
Diabetes, Blood pressure and other chronic diseases should be in continous check and health. Any elevated levels of your blood pressure or sugar levels can adversely affect your eyesight.
Avoid straining your eyes:
You should not strain your eyes very much. You should always keep lighting in appropriate settings and amount while reading. Eye exercises can help relax your muscles of eyes and also strengthen them. You should avoid screen time and take breaks often while you are working on the computer to reduce the stress and exertion.
Wear sunglasses for light sensitivity:
UV radiation present in the sun light is harmful and can damage your eyes. You should wear the sunglasses to help protect your eyes while you are out in the sun.
Have an annual ophthalmological visit:
Keep your eye prescriptions updated and get your eye checkups regularly.
For Taste and Smell
As discussed and explained above, your sense of taste and sense of smell are interlinked. When you have a loss in smell sense, you are more likely to lose your taste sense and vice-versa.
Maintain proper oral hygiene:
Your inappropriate dental hygiene or overall oral health can lead to issues with your sense of taste and smell. Any infection or disease pertaining to your gums or teeth can adversely affect your nasal cavity and taste buds. So, maintaining a good overall oral hygiene is iimportant.
Limit your salt intake:
Consuming excessive amounts of salt can potentially destroy your taste buds. You should reduce your salt intake so as to improve your taste sense and eventually maintain your sodium levels. This will also improve your blood pressure levels.
Nutrition is Vital:
Your should avoid foods that can potentially cause any allergies, tonsillitis, or sinusitis, as they can affect both your taste sense and smell sense. Consuming a healthy diet and experimenting different types of cuisines once in a while can help enhance the activity of your taste buds.
For Touch
Any skin changes, particularly with natural ageing, can reduce its sensitivity.
Keep yourself physically active:
Any blood circulation issues can lead to the loss of touch sensation. Physical activities including walking, running, exercising and swimming, can help you maintain your blood circulation.
Maintain healthy skin hygiene:
You should take care of your skin health. To avoid any skin problems, you should take a bath every day and use all the good-quality products including creams and lotions. Keep your skin hydrated with consuming plenty of water. Always remember to use sun blockers including sunscreen while venturing out in the sun.
Have a healthy diet:
Consuming a well-balanced and nutritious diet always fuels you and your nerves and brain. This helps you to keep your skin in health.
For Hearing
Hearing loss or impairment is a common concern among the aged or elderly.
Protect the ears from loud noises:
Hearing loss or the damage to hearing ability can sometimes be irreparable. You should protect your ears from any loud noises by wearing earplugs. Also, you should keep the volume of music or TV low while watching or listening.
Lessen the background sounds:
You should try to minimise any unnecessary background sounds like you are not watching TV, you should switch off the television, also avoid any noise or crowded places, etc.
Visit an ENT specialist for any hearing problem:
If you experience certain hearing issues, you should visit a specialist in ENT. Any hearing devices used for some specific or partial loss in hearing ability can help minimise strain in the ear which helps in an effective hearing capacity.
Frequently Asked Questions
What is the function of sense organs?
The sense organs- the eyes, ears, nose, tongue, and skin, ensure senses of sight, hearing, smell, taste, and touch. These senses help improve longevity and learning while helping in better adaptation and enhancing the quality of life.
Which is the largest sense organ?
Skin is the largest sense organ for any organism. It provides a sense of touch and is a barrier that protects the organism from external environmental factors.
Can people have no sense of touch?
You can have numbness or complete loss of sensitivity. It is a medical condition when people experience no touch sensation. People can even have partial or reduced sensitivity loss in some body parts.
Conclusion
The five main sense organs- eyes, nose, ear, skin, and tongue. The sense organs are an essential part of perceiving the external stimuli, keeping their health and care is also crucial. Consuming a diet rich in nutrients and minerals, and getting regular health check-ups can help keep your sense organ in optimal functioning, health and strength.
