Sense organs lesson 9th class plzzz...... I, ve tmr exam
Answers
Explanation:
Sense Organs Definition
“Sense organs are the organs that respond to external stimuli by conveying impulses to the sensory nervous system.”
Table of Contents
Sense Organs
Types
Eyes
Ears
Tongue
Nose
Skin
Other Sense Organs
Vestibular system
Proprioception system
What are the Sense Organs?
Sense organs are specialized organs that help to perceive the world around us. They are an integral part of our lives and it is the only way that enables us to perceive the environment.
Sense organs provide the required data for interpretation through various organs and a network of nerves in response to a particular physical phenomenon. These senses govern our association and our interaction with the environment.
We have five sense organs, namely:
Eyes
Ears
Nose
Tongue
Skin
These five sense organs contain receptors that relay information through the sensory neurons to the appropriate places within the nervous system. The receptors could be classified into two parts viz. the general and special receptors. The former is present throughout the body while the latter includes chemoreceptors, photoreceptors and mechanoreceptors.
Five Sense Organs
As stated before, we have five sense organs that can receive and relay sensory information to the brain. These senses provide an organism with information crucial for perception. The different sense organs and the senses they provide are mentioned below:
Eyes – Sight or Ophthalmoception
These are the visual sensory organs in our body. These are sensitive to light images. The eyes vary in colour depending upon the amount of melanin present in our body. It helps in the sense of sight by detecting and focussing on the light images.
The iris in the eye is the coloured part that controls the size and diameter of the pupil, which directly affects the amount of light entering the eyes. Behind the lens of the eye lies the vitreous body. It is filled with a gelatinous material called the vitreous humour. This substance gives shape to the eyeball and also transmits light to the very back of the eyeball, where the retina is found.
This retina contains photoreceptors, which detect light. There are two types of cells present which perform functions distinct from each other. These are Rod and Cones.
Rods: These sensors function in low light and are found at the edges of the retina. They also aid in peripheral vision.
Cones: These types of retinal cells work best in bright light, detecting fine details and colour. There are three types of cones for detecting three primary colours of light, namely: blue, red and green. Typically, colour blindness occurs when any one of these types of cones are not present.
Also Read: Structure of the Eye
Ears – Hearing or Audioception
Ears are the auditory sense organs of our body. They help us to perceive sounds. Our auditory system detects vibrations in the air and this is how we hear sounds. This is known as hearing or audio caption.
The ears are divided into three sections, namely, outer ear, inner ear, and the middle ear. All sounds are basically vibrations, so the outer ear transfers these vibrations into the ear canal, where these vibrations are transformed by the brain into meaningful sound. Apart from hearing, this sense is also important for balancing our body or equilibrium.
Tongue – Taste or Gustaoception
The tongue helps in perceiving various tastes and flavours. The taste buds are present between the papillae on the tongue—these help in sensing different tastes.
The senses of smell and taste tend to work together. If one could not smell something, they could not taste it either. The sense of taste is also known as gustaoception.