Neurovascular bundle fluid and blood, they tend to have large surface area and short diffusion path. Normally, capillaries consist of a central lumen lined with an endothelium, a single layer of smooth epithelial cells. In contrast, deep neurovascular bundles, with arteries in them, have a more complicated composition. Arteries are the vessels that transfer the blood pumped by the heart to the entire body. Arteries have high intraluminal blood pressure, relative to capillaries and veins. To compensate arteries have a smooth muscle and a connective tissue structure outside the endothelium. This composition allows arteries to contract/relax, be flexible under pressure, and transfer
Blood islands plasma, beginning 3 weeks after fertilization. Blood formation inside the embryo proper begins around 5 weeks after fertilization in the liver, and at the twelfth week in the spleen, red bone marrow and thymus. Blood islands have been seen in the area vasculosa in the vitelline veins and arteries, and in the dorsal aorta. Blood islands Blood islands are structures around the developing embryo which lead to many different parts of the circulatory system. Blood islands arise external to the developing embryo on the umbilical vesicle, allantois, connecting stalk and chorion. They are also known as Pander's islands or Wolff's