. Advanced biology. Biology; Physiology; Reproduction. 74 HUMAN TISSUES. Skin cells colonial proto^oorv iwcmovi/' In most organisms, cells are not separate and distinct units, but are joined to one another by delicate strands of cytoplasm. fore, it may be said that all of the tissue cells work together to accomplish the life processes of the organism. This is brought about by differentia- tion of structure for division of labor. The cells of multi- cellular animals and plants are not isolated individuals, but are probably held together by some kind of cyto- plasmic continuity. Biologists have
. Advanced biology. Biology; Physiology; Reproduction. 74 HUMAN TISSUES. Skin cells colonial proto^oorv iwcmovi/' In most organisms, cells are not separate and distinct units, but are joined to one another by delicate strands of cytoplasm. fore, it may be said that all of the tissue cells work together to accomplish the life processes of the organism. This is brought about by differentia- tion of structure for division of labor. The cells of multi- cellular animals and plants are not isolated individuals, but are probably held together by some kind of cyto- plasmic continuity. Biologists have found in certain cases, and have reason to believe that in most cases, slender cytoplasmic bridges connect the various cells. This gives direct continuity to the cytoplasm throughout the entire organism, and probably enables the organism to act as a unit even though it is composed of millions of different cells. Many cells of the body deposit intercellular materials, which give additional structural strength. The amount of the deposit varies. Bone cells deposit a large amount of such material; epithelium produces a very small amount. Protoplasm is the foundation sub- stance of cells. Groups of similar cells with their intercellular materials make up tissues. When tissues are grouped to make a larger structure to perform a certain function, that structure is called an organ. Thus, the en- tire plant or animal organism is a combi- nation cf organs built of tissues, which in turn are built of cells. The tissues of the human body may be classified into epithelial, supporting or connective, muscular, blood, and nervous. <» ^O U <D 2^ i- 0. 1 Cells The cell is the unit of structure and function in every Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Wheat, Frank Merrill; Fitzpatrick, Elizabeth T
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Keywords: ., bookcentury1900, bookdecade1920, booksubje, booksubjectphysiology
