Blood many invertebrates, these oxygen-carrying proteins are freely soluble in the blood; in vertebrates they are contained in specialized red blood cells, allowing for a higher concentration of respiratory pigments without increasing viscosity or damaging blood filtering organs like the kidneys. Giant tube worms have unusual hemoglobins that allow them to live in extraordinary environments. These hemoglobins also carry sulfides normally fatal in other animals. The coloring matter of blood (hemochrome) is largely due to the protein in the blood responsible for oxygen transport. Different groups of organisms use different proteins. Hemoglobin is the principal determinant of the color of blood
Cardiac neural crest cells a number of functions including creation of the muscle and connective tissue walls of large arteries; parts of the cardiac septum; parts of the thyroid, parathyroid and thymus glands. They differentiate into melanocytes and neurons and the cartilage and connective tissue of the pharyngeal arches. They may also contribute to the creation of the carotid body, the organ which monitors oxygen in the blood and regulates breathing. "Induction" is the differentiation of progenitor cells into their final designation or type. The progenitor cells which will become CNCCs are found in the epiblast about Henson’s node. Progenitor cells are brought into