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Endocrine system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Large pituitary tumours may be detected as a result of pressure on adjacent structures, particularly the optic chiasm that lies above the pituitary, separated from it only by a basal cerebrospinal fluid (CSF) cistern. A tumour growing up into the centre of the chiasm will initially compress the neurons taking visual signals from the medial half of each retina, thus causing a bitemporal hemianopia, or loss of the lateral visual field of both eyes. Large tumours may also present by compressing and reducing the function of the rest of the pituitary gland, causing hypopituitarism.
Bridging Fashion Design and Color Effects
Published in Marcelo M. Soares, Francisco Rebelo, Ergonomics in Design Methods & Techniques, 2016
From the retina, visual information passes to the optic nerve, joining in the optic chiasma. Here, the images are organized in a way that the information that one or both eyes see in the left side of the sight is directed to the left half of the brain, and vice versa.
Tutorial: Theoretical Considerations When Planning Research on Human Factors in Lighting
Published in LEUKOS, 2019
Vision starts in the eye and requires light. Photoreceptors in the outer layer of the retina—the well-known rods and cones—absorb light particles and transduce photic information to neural signals that travel to the optic chiasm via the optic nerve. The retina consists of multiple layers of neurons that are tightly interconnected. These interconnections are the means through which light processing starts immediately, including, for instance, contrast detection, color processing, and very quick adaptation to local and ambient light levels. Typically such processing continues deeper in the brain, but the initiation in the retina implies that, rather than transferring direct pixel-based information like a digital camera, the optic nerve transports preprocessed light information, having already converted individual photoreceptor inputs into, for instance, light- and color channel–based data and accentuating color and light contrasts (both spatial and temporal), which are important for fast downstream (deeper in the brain) detection of, for instance, borders and shapes; that is, object detection. From there, light information takes different routes into the brain. The pathway mainly responsible for vision is that from the optic chiasm, via the lateral geniculate nucleus to the visual cortex. Once the signals reach the cortex, we become consciously aware of them; in other words, we see.