The Five Senses of The Human Body: Facts Figure & Functionality
- Last Updated: Sep 21st, 2018
- Posted by: admin
- Category: Health & Wellness
The Living creature is an amazing miracle of God’s creation. From the very beginning, God created the earth. Subsequently, he created the “LIFE” or “HUMAN“ which became the most powerful creatures on the earth due to his wondrous power of SENSATION.
Normally, a sense is a physiological capacity or conscious awareness of organisms that supply information for perception. Apparently, the senses allow us to experience the world around us. It might be unimaginable to live our lives without our five sense organs.
What are the five senses organs of a human body
The nervous system of our body receive and process the information and later, relay the signals to the brain in order to react with the world. Much of this information reaches us through the 5 senses organs. Those are the eyes, ears, nose, tongue, and skin. However, Sight (vision) must be the most delightful of all the senses. But touch (skin) comes before sight, or even before speech. It is the first expression and the last, and it always mentions the truth.
There are different receptors in each sense organs. One is general receptors and other is special receptors.
- Skin contains general receptors
- Mouth and nose contain a special receptors chemoreceptors (chemical receptors)
- Eyes also contain a special receptors photoreceptors (light receptors)
- Ears contain mechanoreceptors which are also a special receptor.
To illustrate the above, human bodies have five recognized senses: sight, hearing, taste, smell, and touch. Here is a brief description of each of these.
5 senses of the body and their functions
The sense of SIGHT (Ophthalmoception)
- An eye is an organ responsible for Vision to detects visible images and most use more than any other sense.
- It translates light into image signals for the brain through the various parts like sclera, the cornea, anterior & posterior chambers, iris, pupil, lens, vitreous humour, retina, fovea, macula, and the ophthalmoscope.
- The iris is the coloured part of the eye which actually is a pigmented muscle that controls the size of the pupil. Pupil dilates to allow more light into the eye or contracts to allow less light into the eye. Cornea covered both iris and pupil.
- The cones and the rods are the two types of light-sensitive cells in the retina. When the cones distinguish colours, the rods allow us to see better in dim light. And, by the optic nerve, all of this information is sent to the brain.
- The images actually sent are upside down but our brain help to understand what it is by turning the image on the right side up.
Problem with ophthalmoception
The inability to see is blindness, results from any damage to any part of the eyes. Cleaning of the eyes, eye drops, surgery, and laser treatments available to cure severe vision impairment.
The sense of HEARING (Audioception)
- The sense of sound perception is hearing. Our ears help us to hear. It is divided into 3 parts i.e. the outer ear, middle ear, and the inner ear.
- The ear uses bones, hairs, and fluid to convert sound waves into sound signals.
- The hearing is the mechanical motion of the vibrations detected in the inner ear through a series of tiny bones to tiny hairs.
- At first sound wave hits the eardrum, then the eardrum make the tiny bones like the malleus, incus, and the stapes moves.
- Mechanoreceptors picked this movement in the inner ear. These receptors exist on hair cells and it contains cilia between the vestibule and the end of the semicircular canals.
- As cilia move, an impulse is created by the cells that are sent to the eight cranial nerve through the cochlea.
- The cranial nerve carries impulse to the nerve and then the brain interprets the information as a valid sound.
Problem with Audioception
Hearing impairment or deafness is the inability of hearing. Few medications, therapies, and surgeries are recommended to cure hearing. While, in some cases, hearing aid also helpful for severe deafness to some extent.
Some impaired people are able to determine the direction and location of vibrations picked up through the feet.
The sense of TASTE (Gustation)
- It refers to the thought of flavour felt in the mouth and throat in touch with any substances such as food, certain minerals, chemicals, and toxin, etc. Remember it is fully different from the sense of smell.
- Taste buds, sensory organs on the top of the tongue or mouth connected to nerves in the brain. Taste buds contain chemoreceptors.
- The taste buds actually lie down in the grooves between each papilla. Papila is the little bumps on the tongues.
- When food touches the taste buds, it activates nervous receptors which later send signals to facial, glossopharyngeal, and vagus nerves.
- Those nerves carry the signals to the medulla oblongata, which deliver them to the cerebral cortex of the brain.
- There are five basic tastes: saltiness, sourness, sweetness, bitterness, and umami.
- In addition, a taste sense depends on other senses and factors, including smell, texture, and temperature.
Problem with Gustation
The incapability to taste is called ageusia. Certain medications may help to treat ageusia e.g. Topical antifungal or antibiotics: candidiasis/oral infections.
The sense of SMELL (Olfaction)
- Our nose, containing the nostrils used for breathing and smelling. Without it, we couldn’t able to enjoy our favourite smells like a fragrance of cooking, a bouquet of flowers, and perfumes etc.
- Olfaction, a sense of smell, have minimum 390 olfactory receptors at the top of the nasal cavity.
- The olfactory cells are chemoreceptors, these protein receptors can detect subtle differences in chemicals.
- When inhaled, those triggers a signal that travels to the olfactory bulbs through the epithelium.
- The olfactory bulbs contain neuron cell bodies, they send the signal along the cranial nerves towards the cerebral cortex in the brain.
- Our sense of smell is able to determine seven types of sensations. Those are camphor, ether, musk, flower, mint, acrid, or putrid.
Problem with Olfaction
Anosmia is the loss of the sense of smell. Intranasal theophylline spray and smell therapies help in improving the sense of smell.
The sense of TOUCH (Somatosensation)
- Although the skin is the largest organ in our body, touch is perhaps the most unnoticed sense of the body. Nerve endings and specialized neural receptors in the skin (including hair follicles, tongue, throat, and mucosa) send touch signals to the brain.
- Blind people can use their sense of touch to read Braille which is a type of reading or writing.
- Generally, touch sensation first develops in the 8 weeks of the gestation period.
- The skin consists of three major tissue layers: the outer epidermis, middle dermis, and inner hypodermis. Specialized receptor cells within these layers detect tactile sensations and send those signals through peripheral nerves towards the brain.
- Receptors, for example, Merkel cells, are forms in the lower epidermis of lips, hands, and external genitalia.
- Similarly, Meissner corpuscles are found in the upper dermis of hairless skin such as fingertips, nipples, the soles of the feet. All of these receptors detect touch, pressure, and vibration.
Problem with Somatosensation
Tactile anaesthesia is the loss of the ability to feel anything touched. Paresthesia is a sensation of tingling, pricking, or numbness of the skin that occurs due to nerve damage.
Apart from these, other senses like balance and acceleration, thermoception, proprioception, pain, sexual stimulation, and other internal senses are normally stimulated within the body that leads to enhancing the human’s life.
Proprioception can be termed as sixth sense of the human body.
Balance and acceleration: It is the sense that allows an organism to sense body movement, direction, and acceleration, and to attain and maintain postural equilibrium and balance.
Thermoception: It is the sense of heat and the absence of heat (cold) by the skin and internal skin passages.
All of the nerves in our body connect to the spinal cord (over our backbone), which attach to the brain. Hence, this very complex system is what allows us to sense things and thus makes our life wonderful.
We have 5 senses in our body. The 5 Senses interpret the world around us as we can find out and grasp whatever is happening around us. Watch this video to know more: