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Embryonic vertebrate subdivisions of the developing human brain hindbrain or rhombencephalon is a developmental categorization of portions of the central nervous system in vertebrates. It includes the medulla , pons , and cerebellum .
The subthalamic nucleus (STN) is a small lens-shaped nucleus in the brain where it is, from a functional point of view, part of the basal ganglia system. In terms of anatomy, it is the major part of the subthalamus. As suggested by its name, the subthalamic nucleus is located ventral to the thalamus.
The visual cortex is responsible for processing the visual image. It lies at the rear of the brain (highlighted in the image), above the cerebellum. The region that receives information directly from the LGN is called the primary visual cortex (also called V1 and striate cortex). It creates a bottom-up saliency map of the visual field to guide ...
There are about 0.7 to 1.5 million retinal ganglion cells in the human retina. [2] With about 4.6 million cone cells and 92 million rod cells, or 96.6 million photoreceptors per retina, [3] on average each retinal ganglion cell receives inputs from about 100 rods and cones.
The primary part of the visual cortex, (V1), is located in the calcarine sulcus, and is the first cortical area involved in visual processing. It receives visual input from the lateral geniculate nucleus, which is located in the thalamus.
The brain is protected in a cartilaginous cranium. The giant nerve fibers of the cephalopod mantle have been widely used for many years as experimental material in neurophysiology; their large diameter (due to lack of myelination) makes them relatively easy to study compared with other animals. [16]
The arachnoid mater covering the brain is referred to as the arachnoidea encephali, and the portion covering the spinal cord as the arachnoidea spinalis. The arachnoid and pia mater are sometimes considered as a single structure, the leptomeninx, or the plural version, leptomeninges ( lepto , from the Greek root meaning "thin" or "slender").
Closest to the visual field (and farthest from the brain) is the axon terminal, which releases a neurotransmitter called glutamate to bipolar cells. Farther back is the cell body, which contains the cell's organelles. Farther back still is the inner segment, a specialized part of the cell full of mitochondria.