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Permineralization is a process of fossilization of bones and tissues in which mineral deposits form internal casts of organisms. Carried by water, these minerals fill the spaces within organic tissue. Because of the nature of the casts, permineralization is particularly useful in studies of the internal structures of organisms, usually of ...
Tree remains that have undergone petrifaction, as seen in Petrified Forest National Park. In geology, petrifaction or petrification (from Ancient Greek πέτρα (pétra) 'rock, stone') is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals.
The pericardium (pl.: pericardia), also called pericardial sac, is a double-walled sac containing the heart and the roots of the great vessels. [1] It has two layers, an outer layer made of strong inelastic connective tissue (fibrous pericardium), and an inner layer made of serous membrane (serous pericardium).
A functional explanation for the enigmatic turning of the heart and bowels is lacking, but one theory does give an explanation for the evolution and development of this phenomenon. According to this axial twist theory, this is due to a twist in the body of all vertebrates that occurs in the early embryo. The twist turns the anterior head (with ...
Serous membrane lines the pericardial cavity and reflects back to cover the heart—much the same way that an underinflated balloon would form two layers surrounding a fist. [ 1 ] The serous membrane (or serosa ) is a smooth tissue membrane of mesothelium lining the contents and inner walls of body cavities , which secrete serous fluid to allow ...
In the process, metabolites, or byproducts, of the drug are produced, which can linger in our blood, urine (and even in our hair) for long after the initial effects of the drug are felt.
Fossils vary in size from one-micrometre (1 μm) bacteria [14] to dinosaurs and trees, many meters long and weighing many tons. A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates , or the chitinous or calcareous ...
Learn how muscle memory works, how long it takes to develop, and why it’s crucial for fitness. Plus, tips to train smarter and build strength and muscle faster. Your Body Never Forgets Muscle.