A person receives information about the environment using sensor systems, or analyzers.
Sensory system (analyzer) – a set of structures of the nervous system that receive, process information of a certain type and form sensations.
All analyzers are built on the same principle and consist of three sections: peripheral, conductive and central.
The peripheral section is represented by receptors.
Receptors are nerve endings or sensory cells that convert an external signal into nerve impulses.
The conduction section delivers information to the brain and is represented by sensory nerve fibers.
The central department of the analyzer provides analysis of the information received and its transformation into sensations. The central section is located in the cerebral cortex.
Sensations arise only if each of the three parts of the analyzer performs its functions.
Example: a person can lose hearing not only due to ear disease, but also due to damage to the auditory nerve and the auditory cortex of the cerebral hemispheres.
The term “sense organs” is often used.
The sense organ is an anatomical formation that perceives external influences.
The sense organs include receptors and auxiliary structures. So, the organ of vision consists of the eyeball (visual receptors are located in it) and eyelids, eyelashes, lacrimal glands (they perform a protective function).
A person has six senses:
- organ of vision – the eye,
- organ of hearing – ear,
- organ of touch – skin,
- organ of smell – nose,
- the organ of taste is the tongue,
- the organ of balance is the vestibular apparatus.