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The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles [1] and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell and contained within the nuclear membrane is termed the nucleoplasm .
Defining cerebral cytoarchitecture began with the advent of histology—the science of slicing and staining brain slices for examination. [2] It is credited to the Viennese psychiatrist Theodor Meynert (1833–1892), who in 1867 noticed regional variations in the histological structure of different parts of the gray matter in the cerebral hemispheres.
[19] [20] [23] Furthermore, if specific cells were isolated in a petri dish from the whole structure, these cells will still form the structure or tissue they were going to form initially. [ 19 ] [ 20 ] [ 23 ] In other words, the signaling to form a specific tissue is within the tissue not coming from a central organ or system.
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. [2] In eukaryotes , it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms.
The proteins contain a signal sequence that allows the Golgi apparatus to recognize and direct it to the correct place. Golgi apparatus also produce glycoproteins and glycolipids. [21] Lysosome: The lysosome functions to degrade material brought in from the outside of the cell or old organelles. This contains many acid hydrolases, proteases ...
Brain cells make up the functional tissue of the brain. The rest of the brain tissue is the structural stroma that includes connective tissue such as the meninges , blood vessels , and ducts. The two main types of cells in the brain are neurons , also known as nerve cells, and glial cells , also known as neuroglia. [ 1 ]
Thus for a 1 mm diameter cell, the vacuole can have a diameter of 0.8 mm, leaving only a path width of about 0.1 mm around the vacuole for cytoplasm to flow. The cytoplasm flows at a rate of 100 microns/sec, the fastest of all known cytoplasmic streaming phenomena. [8]
Quiescent stem cells are Type B that are able to remain in the quiescent state due to the renewable tissue provided by the specific niches composed of blood vessels, astrocytes, microglia, ependymal cells, and extracellular matrix present within the brain. These niches provide nourishment, structural support, and protection for the stem cells ...