Most important Sensory organ

SKIN
it’s well known that the skin is the first line of defense against all elements, such as microorganisms, wind, and pollutants. And it’s the acid mantle, a fine film with a slightly acidic pH on the surface of the skin that provides protection for the skin. It plays a very important role as an integral part of the barrier function of the stratum corneum. Therefore if you didn't have skin you would not be living ing the world right now;)
SIGHT
HEARING
TASTE
SMELL

Sensory Organs- Tongue

In humans, the tongue functions principally in chewing, swallowing, and speaking. The human tongue is covered by a mucous membrane containing small projections called papillae, which give it a rough surface. Tiny taste organs, or buds, are scattered over the surface of three of the four types of papillae, with large numbers concentrated on papillae found on the back and sides of the tongue. The appearance of the tongue is often an indication of body health; a pinkish-red color is normal. In impairment of the digestion and in certain feverish diseases, a yellowish coating forms.

Taste buds are involved in detecting the five elements of taste perception: salty, sour, bitter, sweet, and umami. Via small openings in the tongue epithelium, called taste pores, parts of the food dissolved in saliva come into contact with the taste receptors.

Width:
a wide tongue reflects an overall balanced physical and psychological disposition.
a narrow tongue reflects a lack of physical adaptability with pronounced strengths and weaknesses. Mentally, thinking may be sharp but tend toward seeing a narrow view.
a very wide tongue reflects a generally loose and expanded physical condition and a tendency toward more psychological concerns.
Tip:
a rounded tip reflects a flexible yet firm physical and mental condition.
a pointed tip reflects a tight, perhaps even rigid physical condition and an aggressive or even offensive mentality.
a very wide tip reflects an overall weakness of the physical body and a flaccid or even "spaced out" mental condition.
a divided tip reflects a tendency toward physical and mental imbalances with the possibility of sharp fluctuations in thinking and mood.
Thickness:
a flat tongue reflects a balanced condition and the ability to flexibly adapt to circumstances.
a thin tongue reflects a more mental orientation, with a tendency to be more gentle and easy going.
a thick tongue reflects a more physical orientation, with the tendency to be assertive or even aggressive.
In comparison to structure, the condition of the tongue is influenced more by daily lifestyle and provides information about an individual's current state of health. Qualities to look for include:
Color:
Dark red: indicates inflammation; lesions or ulceration; and sometimes a degeneration of the related organ.
White: indicates stagnation of blood; fat and mucus deposits; or a weakness in the blood leading to such conditions as anemia.
Yellow: indicates a disorder of the liver and gallbladder, resulting in an excess secretion of bile; deposits of animal fats, especially in the middle organs of the body; and possible inflammation.
Blue or Purple: indicates stagnation of blood circulation and a serious weakening of the part of the digestive system that corresponds to the area of the tongue where the color appears.
The color on the underside of the tongue can also be used to determine the internal condition. In general, the colors and their indications listed above are the same, with the following exceptions:
Blue or Green: In excess, either of these color reflect disorders in the blood vessels and in blood quality and circulation.
Purple: In excess, this color reflects disorders of the lymphatic and circulatory system. It indicates a weakening of the immune ability and of the blood vessels.
Texture:
a swollen or enlarged tongue: indicates a Jitsu, or full state.
a shriveled or withered-looking tongue: indicates a Kyo, or empty state.
Movement:
the flexibility of the tongue also reflects the condition of the digestive system. Characteristics to look for include:
a flexible, supple, smoothly moving tongue.
a stiff, tense, or inflexible tongue.
a loose or lolling tongue.
a tongue with a pronounced slant to the left or right when it is extended.

Chapter 7: The Nervous System - objective 8

Classify neurons according to structure and function:

• A NEURON is a simulation environment for modeling individual neurons and networks of neurons.

Neurons exist in a number of different shapes and sizes and can be classified by their morphology and function. Neurons are classified into two types; type I with long axons used to move signals over long distances and type II without axons. Type I cells can be further divided by where the cell body or soma is located. The basic morphology of type I neurons, represented by spinal motor neurons, consists of a cell body called the soma and a long thin axon which is covered by the myelin sheath.

The soma is the central part of the neuron. It contains the nucleus of the cell, and therefore is where most protein synthesis occurs.
The dendrites of a neuron are cellular extensions with many branches, and metaphorically this overall shape and structure is referred to as a dendritic tree. This is where the majority of input to the neuron occurs.
The axon is a finer, cable-like projection which can extend tens, hundreds, or even tens of thousands of times the diameter of the soma in length. It carries nerve signals away from the soma (and also carries some types of information back to it).