We have 5 senses – sight, smell, sound, taste and touch. Each one of them is really important in your everyday life. 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. All of this information coming us through the 5 senses organs of human body. You use every time at least one of your five senses every day and no matter you’re asleep they are on duty always. Our Body senses work together to let our brain know what is going on around us. They help to keep us safe by warning of any danger which would be happen.
Normally, a sense is a physiological capacity that supply information for perception. Apparently, the senses allow us to experience the world around us. It might be impossible to live our life without our five sense body organs.
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.
A good sense of sight is achieved by healthy eyes. Eyes are the organs of the visual system of our body. Our body can have different different eye colours depending on the amount of melanin present in our body and the eye color can vary from brown to blue.
- Eyes is an organ which is responsible for Vision to detects the visible images and most use more than any other sense.
- 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.
- 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 coloured part of the eye is Iris which actually is a pigmented muscle that controls the size of the pupil.
The organ for the sense of smell is the nose. But we breathe through nostrils. The Nose is an olfactory system which is responsible for our sense of smell.
- 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.
- The sense of smell is able to determine different types of sensations. Those are camphor, mint, musk, flower, ether, acrid, or putrid.
- When inhaled, those triggers a signal that travels to the olfactory bulbs through the epithelium.
The organ for the sense of hearing is ears. Hearing or auditory perception is the ability to perceive sound by detecting vibrations, changes in the pressure of the surrounding medium through time, through an organ such as the ear.
- 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 hearing is the motion of the vibrations detected in the inner ear through a series of tiny bones to tiny hairs.
- The ear uses bones, hairs, and fluid to convert sound waves into sound signals.
- At first sound wave hits the eardrum, then the eardrum make the tiny bones like the malleus, incus, and the stapes moves.
The Tongue is known as the sense of taste organ. The tongue has various sensory receptors which can detect whether the food is salty, sweet, bitter or sour. The behind part of the tongue detects bitter taste, the frontmost part detects salty taste, the side part detects sour taste and the middle and front part detects sweet taste.
- The taste buds actually lie down in the grooves between each papilla. Papila is the little bumps on the tongues.
- When you eat the food and it touches the taste buds, it activates nervous receptors which later send signals to facial, and vagus nerves.
- There are five basic tastes: saltiness, sourness, sweetness, bitterness, and umami.
The organ for the sense of touch is skin. Skin is the largest organ which situate all over the human body. Various receptors are used for different situations like pain, temperature, pressure, etc.
- Blind people can use their sense of touch to read Braille which is a type of reading or writing.
- Receptors, E.g. Merkel cells are forms in the lower epidermis of lips, hands, and external genitalia.
- Generally, touch sensation first develops in the 8 weeks of the gestation period.