Serous fluid major salivary glands produce mixed (serous and mucus) saliva. Another type of serous fluid is secreted by the serous membranes (serosa), two-layered membranes which line the body cavities. Serous membrane fluid collects on microvilli on the outer layer and acts as a lubricant and reduces friction from muscle movement. This can be seen in the lungs, with the pleural cavity. Blood serum is the component of blood that is neither a blood cell, nor a clotting factor. Blood serum and blood plasma are similar, but serum does not contain any clotting factors, such as fibrinogen, prothrombin, thromboplastin and many others.
Angiocrine growth factors Angiocrine growth factors Angiocrine growth factors are molecules found in blood vessels' endothelial cells that can stimulate organ-specific repair activities in damaged or diseased organs. Endothelial cells possess tissue-specific genes that code for unique growth factors, adhesion molecules and factors regulating metabolism. The discovery emerged after the entirety of active genes in endothelial cells was decoded, resulting in an atlas of organ-specific blood vessel cells. The atlas documented hundreds of already-known genes that had never been associated with these cells. Organs dictate the structure and function of their own blood vessels, including the repair molecules they secrete. Each organ produces