What organ(s)/system(s)/substance(s) /sense(s) of the human body is (are) amazing to you?

This time I going to talk about the Pineal gland because without this don´t would be possible have dreams. This gland have a shape of pine cones, hence the name; is located in the epithalamus, near of the centre of brain and between the two hemispheres. The pineal gland produces melatonin, a seratonin derived hormone, a serotonin derived hormone which modulates sleep patterns in both circadian and seasonal cycles. The most salient regulatory factor in the production of pineal melatonin is the daily alternation of light and darkness. Melatonin levels are higher at night than during the day in all organisms studied so far, regardless of their rest-activity patterns.
The pineal exerts its effect on human physiology through a variety of functions: as an endocrine gland, as a transducer, as a regulator of hormones and as a damped circadian oscillator. While the physiological significance of pineal indoles other than melatonin, and of pineal peptides, has not been thoroughly investigated in humans, melatonin is known or suspected to be involved in mediating all these functions. Extensive animal research has linked pineal melatonin to the expression of seasonal rhythmicity in many mammalian species, to the modulation of circadian rhythms, and to sleep regulation. In addition, reproductive physiology, cardiovascular, and immunological regulation, as well as psychiatric disorders, have been placed under the sphere of influence of this hormone.
                                                 



                                   Did you know...In the PDI extract DMT of the pineal gland of fresh corpses