In the standard industry communications reference model, Open Systems Interconnection (OSI), the Session layer (sometimes called the port layer) manages the setting up and taking down of the association between two communicating end points that is called a connection.
BASIC VISUAL PATHWAYS. A. The pathway: Vision is generated by photoreceptors in the retina, a layer of cells at the back of the eye. The information leaves the eye by way of the optic nerve, and there is a partial crossing of axons at the optic chiasm.After the chiasm, the axons are called the optic tract.The optic tract wraps around the midbrain to get to the lateral geniculate nucleus (LGN), where all the axons must synapse.. Lesions. The easiest way to demonstrate to yourself the consequences of lesions is to strike through a pathway, follow the fibers back to the retina, and see what was affected. Notice that there are lines and numbers drawn on the visual field diagram.
The vast majority of the nerve fibres in the optic tract project to the lateral geniculate nucleus (LGN) in the dorsal part of the thalamus. The LGN is the main relay in the pathway to the primary visual cortex. The projection from the LGN to the visual cortex is called the optic radiation.Because damage at any point along the pathway from the retina to the cortex results in some degree of blindness, this is clearly the pathway through which conscious visual perception takes place in human beings.he image captured by each eye is transmitted to the brain by the optic nerve. This nerve terminates on the cells of the lateral geniculate nucleus, the first relay in the brain's visual pathways. The cells of the lateral geniculate nucleus then project to their main target, the primary visual cortex.