Human body include the heart, lungs and liver. Many organs reside within cavities within the body. These cavities include the abdomen and pleura. The circulatory system comprises the heart and blood vessels (arteries, veins and capillaries). The heart propels the circulation of the blood, which serves as a "transportation system" to transfer oxygen, fuel, nutrients, waste products, immune cells and signalling molecules (i.e., hormones) from one part of the body to another. The blood consists of fluid that carries cells in the circulation, including some that move from tissue to blood vessels and back, as well as the spleen and bone marrow.
Face and neck development of the human embryo tendon, dermis, pia mater and arachnoid mater, sensory neurons, and glandular stroma. Pharyngeal arches are formed during the fourth week. Each arch consists of a mesenchymal tissue covered on the outside by ectoderm and on the inside by epithelium of endodermal origin. In human embryology, there are six arches which are separated by pharyngeal grooves externally and pharyngeal pouches internally. These arches contribute to the physical appearance of the embryo because they are the main components that build the face and neck. In addition, the muscular components of each arch have their own cranial nerve, and wherever the muscle cells