0709-Information Gathering: The Sensory System

Lecture for Year 1 Semester 1 medical student PPSD session on 7th September 2006 by Professor Omar Hasan Kasule Sr.


Vision is physical or moral. The eye is the organ of vision and emotional expression (sadness, pleasure, beauty, communication). Light is a condition for sight. The sources of light are the sun, the moon, the stars, and lamps. Darkness is either physical or moral. Human vision is limited, can be deceived by a mirage, and has poor speed and size discrimination. Blindness can be moral or physical.



The ear is an organ of hearing. Biaural hearing is a bounty from the Creator enabling humans to judge distance. Deafness can be physical or moral.



Human smell and taste sensations are weak. Odors may be pleasant or unpleasant. Smell and taste of food are appetizing, stimulates salivary and gastric secretions. Humans cannot smell out enemies but can smell or taste dangerous and discard harmful substances. The poor food discrimination of babies due to poor smell and taste enables them to like a wide range of food. Poor human smell is a bounty because they are spared many bad odors in the environment. Chemical sensations by chemoreceptors and osmoreceptors are useful in homeostasis.



The skin is a sensory organ. The hand is a sense organ that feels size, shape, and texture. The tactile ability of the hand is the basis of human civilization because it enables manufacture and use of tools. Touch can also be used to show love and intimacy. Somatic pain is a bounty for humans as an early warning of tissue injury. It is the Creator’s bounty that most visceral pain is not felt.


Heat is a discomfort. It is the Creator’s bounty to protect humans from heat by clouds and shades. Cold is the opposite of heat. Cooling rain water and cold drinking water are bounties of the Creator.


Hunger and thirst can be physiological, psychological, and moral. They are a warning to replenish food stocks before depletion and do not always indicate immediate danger or pathology. Diabetes mellitus is associated with hunger and diabetes insipidus is associated with thirst. Moral hunger manifests as loss of control of appetite and not getting satisfied. Hunger is a test of human patience.



It is the Creator’s bounty that humans are not consciously aware if visceral, kinesthetic or propioceptive sensation otherwise they would be overwhelmed by too much information. The Creator wanted humans to concentrate on sensory input from the external and not the internal environment.


Extra-sensory perception (ESP) has been described as inspiration, intuition, instincts, imagination, telepathy, dreams, and revelation. Scientific understanding of ESP is limited. We however know that astrology, foretelling, divination, and sorcery are not valid sources of knowledge or information.

ŠProfessor Omar Hasan Kasule, Sr. September 2007