The human senses are designed for its interaction with the outside world. A person has five of them:
- organ of vision - eyes;
- organ of hearing - ears;
- sense of smell - nose;
- touch - skin;
- taste - language.
All of them respond to external stimuli.
Organs of taste
Man is characterized by taste sensations. This is due to the special cells responsible for the taste. They are in the tongue and are combined into taste buds, each of which has from 30 to 80 cells.
These taste buds are located on the tongue as part of the mushroom-shaped papillae, which cover the entire surface of the tongue.
There are other papillae in the tongue that recognize various substances. Several types are concentrated there, each of which distinguishes “its” taste.
For example, salty and sweet defines the tip of the tongue, bitter - determines its base, and acid - determines the lateral surface.
Olfactory organ
Olfactory cells are located in the upper nasal part. Various microparticles enter the nasal passages of the mucous membranes, so they begin to come into contact with the cells responsible for the sense of smell. This is facilitated by special hairs that are in the thickness of the mucus.
Pain, tactile and temperature sensitivity
The human senses of this species are very important, because it allows you to protect yourself from the various dangers of the world.
Special receptors are scattered on the surface of our body. Cold react to cold, heat respond to heat, pain relate to pain, and tactile touch.
Most tactile receptors are located in the lips and on the fingertips. In other parts of the body, such receptors are much smaller.
When you touch something, tactile receptors are irritated. Some of them are more sensitive, others are less sensitive, but all the collected information is sent to the brain and analyzed.
Vision
The human senses include the most important organ - vision, through which we receive almost 80% of all information about the outside world. The eye, oculomotor muscles, lacrimal apparatus, etc. are elements of the organ of vision.
There are several membranes in the eyeball:
- sclera, called the cornea;
- choroid, passing in front of the iris.
The eyeball inside is divided into chambers filled with jelly-like transparent contents. Cameras surround the lens - a transparent disk for viewing objects that are close and far away.
The inner side of the eyeball, which is opposite the iris and cornea, has photosensitive cells (rods and cones) that convert light fluxes into an electrical signal that enters the brain through the optic nerve.
The lacrimal apparatus is designed to protect the cornea from germs. The tear fluid continuously washes and moisturizes the surface of the cornea, providing it with sterility. This is facilitated by episodic blinking of eyelashes.
Hearing
The human senses include the hearing organ, which consists of three components - the inner, middle and outer ear. The latter is the auditory canal and the auditory meatus. The middle ear is separated from it by the eardrum, which is a small space with a volume of about one cubic centimeter.
The eardrum and the inner ear hide in themselves three small bones, called the "hammer", "stapes" and "anvil", which ensure the transmission of sound vibrations from the eardrum to the inner ear. The sound-perceiving organ is the cochlea, which is located in the inner ear.
The snail is a small tube twisted in a spiral in the form of two and a half special turns. It is filled with a viscous liquid. When sound vibrations enter the inner ear, they are transmitted to the fluid, which sways and acts on sensitive hairs. Information in the form of impulses is sent to the brain, analyzed, and we hear sounds.