In studying the human body, there are some basic anatomical structures to be learned that will greatly help the medical student. The basic anatomical structures are- the skin, the fasciae, the muscle, the joints, the ligaments, the bursae, the synovial sheath, the blood vessels, the lymphatic system, the nervous system, the mucous and serous membrane, the bones, and the cartilages.

The skin is divided into two distinct parts-the epidermis, which is the superficial part, and, the dermis, which is the deeper part. The epidermis is made up of flattened stratified epithelium seen at the surface. In other parts it is so thick like that of the soles and palms of the hands. The dermis is composed of dense connective tissues containing many blood vessels, lymphatic vessels, and nerves. The dermis is thinner in women than in men.

The appendages of the skin are the following- the nails, hair, follicles, sebaceous glands, and sweat glands. The nails are keratinized plates on the dorsal surfaces of the tips of the fingers and toes. Hairs grow out of follicles, which are invaginations of the epidermis into the dermis. A band of smooth muscle, the arrector pili, connects the undersurface of the follicle to the superficial part of the dermis. The muscle is innervated by sympathetic nerve fibers, and its contraction causes the hair to move into a more vertical position. The pull of the muscle causes dimpling of the skin surface giving the so-called gooseflesh.

The sebaceous glands pour their secretion, the sebum, into the shafts of the hairs as they pass up through the necks of the follicles. The sebum is an oily material that helps to preserve the flexibility of the emerging hair. It also oils the epidermis around the hair follicle.

The sweat glands are long, spiral and tubular glands distributed over the surface of the body, except the lips, nail beds, gland penis and clitoris. They extend through the full thickness of the dermis and their extremities may lie in the superficial fascia. The sweat glands are therefore the most deeply penetrating structures of all the epidermal appendages.

The fascia is the membranous tissue that lies between the skin and muscles, and between muscles and bones. It is divided into two types- the superficial and the deep fascia. The superficial fascia or subcutaneous tissue is a mixture of loose areolar and adipose tissues that unites the dermis of the skin to the underlying deep fascia. It contains numerous bundles of collagen fibers that hold the skin firmly to the deeper structures. The deep fascia is a membranous layer of connective tissue that invests the muscles and other deep structures. In the neck it forms well-defined layers, which may play an important role in determining the path taken by pathogenic organisms during the spread of infection. In the thorax and abdomen, it is merely a thin film of areolar tissue covering the muscles and aponeuroses. In the limbs it forms a definite sheath around the muscles and other structures, holding them in place. Fibrous septa extend from the deep surface of the membrane, between the groups of muscles, and in many places divide up the interior of the limbs into compartments. In the region of the joints, the deep fascia may be considerably thickened to form a restraining bands called retinacula.