Final answer:
The tissue that covers and lines the body's surfaces, organs, and vessels is epithelial tissue. It protects the body and also facilitates absorption, transport, and secretion.
Step-by-step explanation:
The basic tissue type that covers and lines organs, vessels, and cavities in the body is known as epithelial tissue. This type of tissue forms large sheets of cells that serve primarily to protect the body. Epithelial tissue not only covers external body surfaces and lines internal cavities but also forms much of the glandular tissue in the body. It includes the outer layer of skin, the linings of the airways and of the digestive, urinary, and reproductive systems. A special type of epithelium called endothelium lines the inner surfaces of blood vessels and serous membranes of body cavities. The function of epithelial tissue extends beyond protection and includes absorption, transport, and secretion.