GERON255 Lecture Notes - Lecture 13: Master Clock, Mutationism, Mutation
Document Summary
Universal occurs in all members of a given species. Progressive must become more obvious as a person gets older. Deleterious produces changes that lead to dysfunction at the cellular, tissue, and organ system levels. Continuously mitotic: cells that divide and produce new cells throughout the lifespan of the organism, rates of division decrease with age. Fibroblast cells (major cells in connective tissue that secrete collagen and elastin fibres), boone marrow cells, and cells of the epithelium (cells which line the digestive tract and skin cells. Post-mitotic: cells which divide during embryogenesis then stop, do not divide during adult life. Semi-mitotic: reverting post-mitotic cells, normally do not divide , but when injured they will. Theories of aging can be divided into two broad categories: Aging is based solely on random events. There theories are also called stochastic theories. Overview of some random theories of aging to be discussed: