Super Senses of Animals and Sense Organs for Class 5 Science
- Sense organs are the special organs in our body that help us perceive and react to external stimuli.
- Sense organs have special sensory receptors that receive signals and relay the same to the brain.
- The brain then interprets those signals and helps us act accordingly.
- The eyes, ear, nose, skin and tongue are five sense organs, of which the skin is the largest organ and covers our whole body.
- Sense organs, the brain, spinal cord and nerves make the nervous system.
- Sense organs in animals are highly developed. We will get to know more about super senses of animals after reading the content given below.
How Does the Retina of Our Eye Help in the Identification of Colours?
- The retina is a specific place in our eye where image formation takes place.
- The membrane of the retina has two types of cells—rods and cones.
- The rod cells in the retina respond to the intensity of light, and the cone cells to the colours of light.
- Hence, the electrical impulses generated as a response of cone cells help us identify the colours.
How Do the Eyes Control the Entry of Light?
- The light entering the eye is controlled by the iris and pupil.
- The size of the pupil is controlled by the muscles of the iris.
- When the intensity of light is high, the pupil contracts, dilating when light intensity is dim.
What Is ‘Cataract’?
- A cataract is an eye disorder where the vision becomes blurry because the lens in the eye turns cloudy.
- It generally occurs due to old age.
What Is Blind Spot? Why Is No Vision Possible at the Blind Spot?
The blind spot is where the optic nerve and retina of the eye unite. At this point, there are no light-sensitive cells which are necessary for vision.
What Do You Understand by a Range of Vision? What Is the Range of Vision of the Human Eye?
- The range of distance for which the objects are clearly visible is called the range of vision of the human eye. It is 25 cm to infinity for the human eye.
- It means that an object is visible to us from close up when it is at a distance of 25 cm from our eye. And we can see objects from an infinite distance.
What Helps To Retain the Spherical Shape of Our Eyeballs?
There is a thick liquid called vitreous humour present in our eyeballs. It helps to retain the spherical shape of our eyeballs.
Name the Smallest Bone in the Human Body. Where Is It Found?
The middle ear comprises three bones—stapes, incus and malleus—called ossicles.
The stapes is the smallest bone among the ossicles and the smallest bone in the human body.
What Is the Function of Ear Wax?
Ear wax is a thick solid substance found in our ear canal. Its functions are as follows—
- To retain moisture and prevent any infections in the ear.
- Prevent dust or insects from entering the ear.
The Nose and Ears Never Stop Growing. Comment.
After puberty, our body stops growing. But with age, the cartilage (soft bones in our ears and nose) starts losing its rigidity. It makes ears and nose lose, and due to gravity, they start appearing to sag.
Where Are the Thickest and Thinnest Skin Patches Located in the Human Body?
The thickest skin patch is found on the feet, and the thinnest skin patch is on our eyelids.
How Does Skin Help in Body Temperature Regulation?
- The skin in our bodies contains blood vessels.
- When the body's temperature rises, the blood vessels dilate to lose the extra heat. It happens with the extra volume of blood flowing through the vessels.
- When our body is cool, the blood vessels get narrowed, which limits the amount of blood flowing. Hence, the body heat gets retained in the body.
How Do We Develop a New Outer Layer of Skin on a Wound or a Scratch?
- Our skin cells are capable of making new cells. These new cells combine to create a new layer of skin over the wound or scratch.
- This process starts after the formation of a clot. The time required for developing a new layer of skin depends on the type of injury.
Super Senses of Animals
Why Is the Sense of Smell in Dogs Well-Developed?
The sense of smell in dogs is well-developed due to the following reasons—
- They have around 300 million olfactory receptors, i.e., cells that sense smell in the nose lining.
- The part of the brain that controls the sense of smell is 40 times larger in dogs than in humans.
What Enables an Elephant To Hear the Faintest Sound From Far Distances?
- The function of the external ear is to gather sound waves from the surroundings.
- The large external ears in elephants help them to gather sound waves from a distance and hear the faintest sounds around.
Why Do You Think Mosquito Repellent Creams Have a Strong Odour?
- Mosquitoes identify their host with the help of the odour of carbon dioxide they release.
- Mosquito repellents are purposely provided with a strong odour to overpower the smell of carbon dioxide and keep us away from mosquitoes.
Whiskers Enable a Tiger To Know About the Slightest Change Around It. Do You Think the Whiskers Work Like a Sense Organ?
- Yes, whiskers work like sense organs. They are adapted to sense every small change happening in the surroundings. They receive the external stimulus, which generates a nerve impulse as it occurs in the case of sense organs.
- This nerve impulse is then sent to the brain, and the animal acts as the brain commands.
Why Do You Think Rabbits Have Long Ears?
Rabbits have long ears, and these help them in the following ways—
- The ears help detect the faintest sounds in the surroundings.
- They help the rabbits to regulate their body temperatures. The body's heat is lost via the ears when it becomes too hot.