This chapter focuses on several organs that collectively provide the individual with their insight into the outside world. The ability to ‘sense’ is a primitive function developed through thousands of years of evolutionary change. The senses are taken for granted by those with a fully functioning ability, but for many a combination of congenital, degenerative and acute pathologies results in a decreased ability in one or more of these functions. | Chapter 11 The Senses Introduction This presentation focuses on several organs that collectively provide the individual with their insight into the outside world. The ability to ‘sense’ is a primitive function developed through thousands of years of evolutionary change. The senses are taken for granted by those with a fully functioning ability but for many a combination of congenital, degenerative, and acute pathologies result in a decreased ability in one or more of these functions. This can have major affects on the individuals ability to function, their mental health and the way they are perceived and treated by the society they live in. The Eye (Sight) The eyes are only one of a number of structures involved in achieving the sense of vision, these include: The eyelids The lacrimal glands The extrinsic muscles of eye movement The eyelids are composed of very fine skin and muscle, connective tissue containing oil secreting sebaceous glands and the conjunctiva. The lacrimal gland is anatomically located laterally and superiorly within the eyes orbit. This gland works in unison with glandular cells to lubricate and moisten the eye. The Eye Lateral Illustration & Anterior Photograph Eye Functioning The function of the eyes centres on providing the individual with vision. Vision consists of several vital concurrent functions, the properties of which include brightness and colour. When vision is normal, seeing is so effortless that the individual functions that comprise vision are imperceptible. Vision is composed of three distant perceptions: Forms Colours Movement Central Interpretation The eyes must continually adapt to meet the external environment. In daylight the eye uses photopic vision. Colours are varied and easily distinguishable due to the action of three different types of cone cells that sense three respective bands of colour. Scotopic vision is the primary source of vision; since cone cells are nonfunctional in low light. Mesopic vision is a . | Chapter 11 The Senses Introduction This presentation focuses on several organs that collectively provide the individual with their insight into the outside world. The ability to ‘sense’ is a primitive function developed through thousands of years of evolutionary change. The senses are taken for granted by those with a fully functioning ability but for many a combination of congenital, degenerative, and acute pathologies result in a decreased ability in one or more of these functions. This can have major affects on the individuals ability to function, their mental health and the way they are perceived and treated by the society they live in. The Eye (Sight) The eyes are only one of a number of structures involved in achieving the sense of vision, these include: The eyelids The lacrimal glands The extrinsic muscles of eye movement The eyelids are composed of very fine skin and muscle, connective tissue containing oil secreting sebaceous glands and the conjunctiva. The lacrimal gland .
