SBPMD Histology Laboratory Manual
The cardiovascular system is composed of the heart and a continuous system of blood vessels. The cardiovascular system and the lymphatic vessels together form the circulatory system. An endothelium (a simple squamous epithelium) lines the circulatory system and there are important histological differences in the composition of the tunics or layers that comprise the remaining wall of the various components of this system. The system consists of the heart, arteries, arterioles, capillaries, venules, veins, and lymphatic vessels.