China
Africa
Explore chapters and articles related to this topic
Vision and Higher Cortical Function
Published in Andrei I. Holodny, Functional Neuroimaging, 2019
Sonia Gill, John Ulmer, Edgar A. DeYoe
As outlined in Figures 3 and 4, the visual system does not end in the calcarine sulcus. Beyond VI, there are multiple additional vision-related areas (numbering more than a dozen, not all shown in Fig. 3) that, collectively, extend throughout the entire occipital lobe and into adjoining portions of parietal and temporal cortex (and even into frontal lobe “eye fields”). Most areas contain a more or less complete map of the visual field, albeit represented more coarsely at each successive level. Beyond medial occipital cortex (V1/V2), however, lesions may not produce localized blindness but rather a selective loss of some vision-related functions while sparing others depending on which areas and anatomical interconnections are affected.
Head, neck and vertebral column
Published in David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings, McMinn’s Concise Human Anatomy, 2017
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings
Calcarine sulcus - on the medial surface of the posterior occipital lobe (Fig.3.7). The adjacent cortex is the visual area (supplied by the posterior cerebral artery), where visual impulses reach consciousness.
The viva: operative surgery and surgical anatomy
Published in Vivian A. Elwell, Ramez Kirollos, Syed Al-Haddad, Neurosurgery, 2014
Vivian A. Elwell, Ramez Kirollos, Syed Al-Haddad
The calcarine fissure is an anatomical landmark located at the caudal end of the medial surface of the brain. The calcarine sulcus begins near the occipital pole in two converging rami and runs forward to a point a little below the splenium of the corpus callosum, where it is joined at an acute angle by the medial part of the parieto-occipital sulcus. The anterior part of this fissure gives rise to the prominence of the calcar avis in the posterior cornu of the lateral ventricle.
An Overview of Preferred Retinal Locus and Its Application in Biofeedback Training for Low-Vision Rehabilitation
Published in Seminars in Ophthalmology, 2022
Shengnan Li, Xuan Deng, Jinglin Zhang
Additionally, Schumacher etal.1811 used fMRI to measure brain activity in the calcarine sulcus while visually stimulating peripheral retinal regions in patients with macular disease. Their results showed that visual stimulation (a fixation cross) of PRL in the retina increased brain activity in the cortex, normally representing central vision relative to the visual stimulation of the perifovea and relative to stimulation in the periphery of age-matched control participants. In brief, the activation of the “fovea” cortex by peripheral stimuli was observed. These data directly combined cortical reorganization with behavioral adaptations adopted by macular damaged patients. fMRI, also used in Baker’s study,15 showed a similar significant activation of peripheral stimuli relative to the fixation baseline at the occipital pole of all participants with complete loss of foveal visual input. All the above-mentioned evidence clearly indicates that cortical plasticity in the visual system remains in patients suffered CVL in life and that the functionalization of PRL is based on visual cortical reorganization which lies on complete foveal visual input loss.
Cortical Visual Connections via the Corpus Callosum are Asymmetrical in Human Infantile Esotropia
Published in Strabismus, 2018
Marcel P. M. ten Tusscher, Anne Cees Houtman, Johan De Mey, Peter Van Schuerbeek
From a morphological point of view (Figure 1), all subjects with IE generally showed an asymmetrical distribution of callosal fibers when comparing the two hemispheres with many fibers terminating near the tips of the occipital cortices. Normal subjects tended to show fibers terminating on the medial aspect of the calcarine sulcus of both hemispheres. This probably corresponds to the visual field representation of the upper and lower vertical meridian which can be found along the calcarine sulcus (below and above respectively). In IE subjects, an increased numbers of fibers appeared along the medial aspect of one hemisphere only. Contralaterally, however, the majority of fibers were directed to the occipital tip.
Ocular ischaemia: signs, symptoms, and clinical considerations for primary eye care practitioners
Published in Clinical and Experimental Optometry, 2022
Michael Kalloniatis, Henrietta Wang, Paula Katalinic, Angelica Ly, Warren Apel, Lisa Nivison-Smith, Katherine F Kalloniatis
The vertebral arteries give rise to their respective posterior cerebellar arteries before converging to form the basilar artery at the base of the skull (Figure 1(b). The posterior and anterior inferior cerebellar arteries and branches from the basilar artery supply the midbrain. The superior cerebellar artery followed by the posterior cerebral artery terminate in the midbrain, supplying the region including cranial nerves III and V (oculomotor and trigeminal). Branches of the posterior cerebral artery also supply the midbrain and the inferior region of the temporal lobe. They also extend to the lateral geniculate nucleus while the parieto-occipital branch terminates in the calcarine sulcus supplying the primary visual cortex.