In the previous article “Anatomy of the Skin” we discussed an overview of the skin and the epidermis. In this article we will focus on the dermis, subcutaneous tissue and deeper layers.
Although the dermis has fewer layers that are much less well defined, it is equally important. The dermis is quite elastic and pliable and is very vascular, owing to the presence of numerous capillary beds that provide nutrition to both layers. Superficial lymphatics located in the dermis are responsible for returning protein, water and other substances from the various body tissues back into the blood vessels.
The dermis has two layers:
- papillary dermis– made up of loosely woven connective tissue fibers embedded in a jelly-like substance known as ground substance. This layer conforms exactly to the contours of the stratum basale of the epidermis. Together with the basement membrane, which acts as a selective filter for substances moving between the two layers, the papillary dermis helps to protect the appendages of the epidermis and provides structure and support to the epidermis.
- reticular dermis– thicker and deeper and is made up of dense connective tissue that is irregularly arranged, providing additional support.
Specialized cells are also found in the dermis. Fibroblasts produce elastin and collagen, which give the skin its elasticity and strength. Mast cells, macrophages and white blood cells assist in fighting infection, each with their own specialized function. The dermis also contains sensory fibers which provide the brain with information on temperature, pressure, vibration and touch.
The dermis serves many functions. In addition to nourishing both layers, it houses the appendages of the epidermis, plays an active role in controlling infection, provides sensation and assists in control of body temperature.
The subcutaneous tissues support the skin and are composed of adipose tissue and fascia. Adipose tissue houses our body’s fat and is made up of loose connective tissue. It also stores fat-soluble vitamins (A, D, E and K). Fascia is made up of fibrous and tough connective tissue that surrounds and separates structures such as bone and muscle and promotes movement between them. Subcutaneous tissue helps to cushy bony prominences.
Deeper tissues include bone, the joint capsules, muscle, ligaments and tendons. Each of these structures has a characteristic appearance. It is important to be able to distinguish between these structures when working with deep wounds that extend into or expose these deeper tissues, particularly if debridement is to be part of your job description.
Understanding the anatomy of the skin is important for any clinician who cares for wounds. Interested in wound care certification? Wound certification can boost your career and, even more importantly, help you to more effectively manage your patients’ wounds. View our wound care courses to learn more.