المشاركة الأصلية كتبت بواسطة SCORPIONKING

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السلام عليكم ..الانسان يملك خمست حواس .النظر ..المس..الشم..الطعم..السمع .القلب ينبض لكي يضخ الدم فقط..عبارة عن مضخت ماء.العقل هوَ سيد الجسد .

المشاركة الأصلية كتبت بواسطة SCORPIONKING

Five classical senses
[Sight

Sight or vision describes the ability of the brain and eye detecting electromagnetic waves within the visible range (light interpreting the image as "sight." There is disagreement as to whether this constitutes one, two or even three distinct senses. Neuroanatomists generally regard it as two senses, given that different receptors are responsible for the perception of colour (the frequency of photons of light) and brightness (amplitude/intensity - number of photons of light). Some argue that stereopsis the perception of depth, also constitutes a sense, but it is generally regarded that this is really a cognitive (that is, post-sensory) function of brain to interpret sensory input to derive new information. Theinability to see is called blindness.

[ Hearing

Hearing or audition is the sense of sound perception and results from tiny hair fibres in the inner ear detecting the motion of a membrane which vibrates in response to changes in the pressure exerted by atmospheric particles within (at best) a range of 9 to 22000 Hz, however this changes for each individual. Sound can also be detected as vibrations conducted through the body by tactition. Lower and higher frequencies than that can be heard are detected this way only. The inability to hear is called deafness.

[ Taste

Taste or gustation is one of the two main "chemical" senses. It is well-known that there are at least four types of taste "bud" (receptor) on the tongue and hence there are anatomists who argue that these in fact constitute four or more different senses, given that each receptor conveys information to a slightly different region of the brain. The inability to taste is called ageusia.
The four well-known receptors detect sweet, salt, sour, and bitter, although the receptors for sweet and bitter have not been conclusively identified. A fifth receptor, for a sensation called umami, was first theorised in 1908 and its existence confirmed in 2000. The umami receptor detects the amino acid glutamate, a flavor commonly found in meat and in artificial flavourings such as monosodium glutamate.

[ Smell

Smell or olfaction is the other "chemical" sense. Unlike taste, there are hundreds of olfactory receptors, each binding to a particular molecular feature. Odor molecules possess a variety of features and thus excite specific receptors more or less strongly. This combination of excitatory signals from different receptors makes up what we perceive as the molecule's smell. In the brain, olfaction is processed by the nose differ from most other neurons in that they die and regenerate on a regular basis. The inability to smell is called anosmia.

[ Touch

Touch also called tactition or mechanoreception, is the sense of pressure perception, generally in the skin There are a variety of pressure receptors that respond to variations in pressure (firm, brushing, sustained, etc). The inability to feel anything or almost anything is called anesthesia. Paresthesia is a sensation of tingling, pricking, or numbness of a persons skin with no apparent long term physical effect.