Intrinsic factors tissue structure

Intrinsic factors that may influence potato digestibility include the structure of the starch molecules, the structure of starch granules, the composition of the potato, the presence of phosphate in starch granules, tissue structure, and factors that may affect these, including agronomic and growth history, storage, maturity, and variety. 

The recognition that cells such as neurons and muscle or cardiac cells, which were previously considered incapable of proliferating in old age, retain the potential for plasticity and regeneration has opened the way to the study of intrinsic and extrinsic factors that may facilitate tissue repair in neurodegenerative diseases of old age. Likewise, the identification of pluripotent cells, such as stem cells, that are potentially capable of acquiring the structure and function of a variety of specialized cells promises to let us effectively replace lost tissues and functions. 

In hemophilia A, the protein sequence of factor VIII is mutated so that it cannot be cleaved, resulting in a blocked intrinsic pathway. Therefore, tissue factor must be activated to stop bleeding (extrinsic pathway). Because the capillaries of joints and muscles are continually damaged by crushing when the surrounding bones and muscles move, they produce small amounts of RNA that activates the intrinsic path. Because there is no tissue factor at that site and the mutation of factor VIII in hemophilia A has blocked the intrinsic path, the affected subjects bleed into the joints. The pressure in the joint eventually stops the bleeding, and reticuloendothelial cells are recruited to remove the blood cells. The pain is relieved, but the joint structure is slowly destroyed and over time surviving individuals develop arthritis. 

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