Dorothy FarrarSense organs
Humans have five sense organs . These are the mouth , nose , eyes , ears and skin . A sensory organ is an organ that is able to capture information from a stimulus and pass it on as an impulse. The stimulus takes place via the nerve fibers , is filtered, compared with the information from the other sensory organs, combined as required, sent to the brain and processed there. What comes out is human perception.
Definition
All sensory organs receive their stimuli via so-called receptors . Each sensory organ picks up different stimuli and transmits them to different regions of the brain. Stimuli to which the sensory organs react are different, they can come from outside, i.e. from the environment, but also from inside, from the body. They are then converted into electrical impulses and sent to the brain.
For the eye it is light, for the ear it is sound, for the skin movement, pressure, pain and temperature are stimuli, for the mouth or tongue it is taste, for the nose it is smell . Only the eyes and ears have exclusive perception functions as sensory organs, the others do not only serve to absorb stimuli.
In addition, there are electric and magnetic fields that have a greater impact on animals than on people. This is the case, for example, with fish or birds. Nevertheless, a person can also see the vibrations of alternating magnetic fields with their eyes.
Anatomy
The largest sensory organ is the skin, which has several functions. First of all, it forms the entire surface and consists of three layers. These are the epidermis , the middle dermis and the hypodermis . The epidermis is divided into four further layers: the horny layer, the granular layer, the spinous layer and the basal cell layer.
The entire epidermis is not supplied with blood, so it is supplied with blood from the dermis , which consists of connective tissue that is supplied with blood . The tactile bodies and sweat glands are located in the subcutaneous tissue. It is pure adipose tissue . The sense of touch occurs via the skin through touch, but also through the absorption of cold, heat and pain stimuli.
The dominant perception in humans is through the eye. In particular, the sense of sight captures light and reflections from the light. This is collected in the eye and converted into neural signals that are sent to the brain. The light beam passes through the cornea , is refracted by the lens , the entire process is upside down and is imaged on the retina . From here, the impulses are sent to the cerebrum via the optic nerve .
The cornea of the eye forms both the protection for the interior and the first refractive moment of the light. This is where the pupil is located , which in turn is surrounded by the iris. The pupil reacts to light or darkness with a reflex and can become smaller or larger. In this way, the eye ensures that the right intensity of light penetrates into the interior and can be transmitted there.
The ear as the sense of hearing is also responsible for the sense of balance. Humans perceive acoustic stimuli up to 20,000 Hertz, i.e. the vibrations per second. The ear consists of the auricle , the auditory canal , the middle ear with the eardrum , the tympanic cavity, the auditory ossicles, the auditory tube and the inner ear as a cochlea.
The internal vestibular apparatus is the organ of balance. The auricle picks up sounds and directs them to the eardrum. The sound is transmitted via all the stations mentioned to the inner ear and the cavity there, the bony labyrinth.
The sensory cells for sound recording are in the third corridor, impulses are generated via nerve processes and from there reach the brain. Sound waves always occur in both ears at the same time when the noise comes from the front, otherwise at different times, which means that humans can detect where the noise is coming from.
The nose as an olfactory organ consists of an outer and inner part, with the inner part reaching into the roof of the mouth. The two sides of the nasal cavity are separated by the nasal septum . The nasal cavity has sieve plates through which olfactory threads that lead to the olfactory bulb pass. The olfactory mucosa, which comes into contact with smell and breathing air, is also located there.
The smell as a perception can trigger salivation . Smell itself is an important feature of human experience.
The tongue in the mouth as a sensory organ for taste consists of a musculature that is covered with a mucous membrane and is attached to the floor of the mouth by a lingual frenulum. It has a root of the tongue, a body of the tongue and the tip of the tongue. Small papillae cause the rough appearance and form the receptors for tactile sensation.
Function
In more highly developed organisms, sensory cells can always be combined into sensory organs. These absorb environmental stimuli via receptors. These receptors are special proteins , and nerve cells in turn form ganglia at certain points with bundled and combined extensions that transmit the impulses.
In order to perceive stimuli via the sensory organs, a stimulus threshold must be exceeded. This limits the area that can be perceived. The stimulus itself must in turn be converted into data that the nervous system can process. Only in this way can the impulse in the brain become a perception.
Diseases
The failure of one sense organ leads to the failure of one of the five senses. Diseases of the sense organs can e.g. B. range in the eye from ametropia to blindness.
This includes the cataract, also known as a cataract, which causes the lens to become cloudy and ultimately liquefies the entire lens. Under these conditions, the ability to see decreases more and more. Increased intraocular pressure is known as glaucoma or green cataracts. The effects are similar.
Sound conduction disorders or hypersensitivity can occur in the ear, which always also affects the sense of balance. This leads to pain reactions that affect the entire nervous system and the organism. The impulses are passed on too quickly or incorrectly, leading to stress reactions, an increase in blood pressure and problems concentrating.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.