PHY3111 Study Guide - Vasculogenesis, Angioblast, Yolk Sac
Document Summary
Colony stimulating factors: stimulate the growth and differentiation of progenitor cells into colonies containing different blood cell types in vitro. Csfs can direct the differentiation of neutrophils and macrophages. Transcription factors: a combination of tfs are responsible for the specific pattern of gene expression that leads to a specific type of differentiated cell. Tunica intima: endothelium = helps prevent sticking of rbcs. Tunica media: muscular = alters rate of blood flow/lumen size. Tunica adventia: elastic layer = maintains vessel integrity. Pulsatile flow (pumping/squirting): in elastic and muscular arteries. Continuous flow (one stream): in capillaries and veins. Formation of blood vessels (in fetus): vascular system is first to develop in vertebrate embryos. Blood vessels develop by two processes; vasculogenesis & angiogenesis. Vasculogenesis - de novo formation of blood vessels from precursor cells, not from preexisting blood vessels. First occurs in blood islands of yolk sac around day 18.
