Sep 26, 2013

The Integumentary System

excerpted from Canine Massage for the Athlete in Every Dog ©2013
C. Sue Furman, Ph.D.

The canine body is made up of eleven different organ systems. Each has a special set of jobs to perform, yet none can function efficiently alone. A healthy dog is evidence that in the face of millions of internal chemical reactions occurring every moment all of the organ systems are working hand-in-hand to maintain a well functioning body. Massage and acupressure have positive effects on each of the organ systems. Following is a brief summary of the structure and function of the integumentary system.

The common integument is the term used to describe the skin and its appendages, which include the hair, nails and skin glands (Fig. 5). We can see the dog's skin, hair and nails, but we can't see many of the components of the skin. It is important to appreciate their many functions. The common integument protects the body, regulates body temperature, senses the environment, synthesizes vitamin D, serves as a blood reservoir, and excretes wastes.

The skin is an organ directly influenced by the touch of massage. Because massage increases circulation to the skin it can improve skin and coat health and decrease or eliminate constant discomfort and scratching due to poor skin condition or infection.

Figure 5. The skin, hair and nails of a dog are what we see. Much of the working machinery of the integument is not visible.

The skin, while thin, is the body's interface with the outside world. It protects the dog from external threats like bacteria and prevents him from losing body water and heat. In the average adult human, the skin has a surface area of 1.5 to 2 square yards and weighs 9 to 11 pounds, which means it accounts for seven percent of the total body weight. These numbers are roughly comparable for our Irish Wolfhound, Great Dane, Mastiff, and other giant breed friends. While the actual values decrease with the size of the breed, they remain proportionally similar. For example, the skin of a Dachshund weighs only one or two pounds but still accounts for approximately seven percent of the dog's body weight (16 to 32 pounds).

The numbers become even more interesting when you consider what you cannot see. It has been estimated that in every square centimeter (a little less than 0.5 square inch) of human skin there are 28 inches of blood vessels, 22 inches of nerves, 100 sweat glands, 15 oil glands, and 230 nervous system sensory receptors that sense touch, temperature, and pain. In addition, there are about half a million skin cells that are continually dying and being replaced. Similar estimates apply to the contents of a square centimeter of surface area of the skin of a dog. Too often, this amazing organ, rich in vessels, nerves, and glands is highly underrated.

Figure 6 - A three-dimensional diagram of the structure of the skin and underlying subcutaneous tissue

The skin is composed of three distinctive layers (Fig. 6). Cells in deepest layer of the epidermis or outer layer of the skin constantly divide. New cells are pushed toward the surface, are keratinized, die and are sloughed. The dermis is a strong connective layer of the skin. It binds the entire body together like a body stocking. The dermis contains blood vessels, lymph vessels, sensory receptors, nerves, and sweat glands. This is where the hair follicles and their associated arrector pili (hair raiser) muscles are found. Extreme cold or fear can stimulate these smooth muscle bundles to contract and the dog's hair literally stands on end. The hypodermis or subcutis is a loose connective tissue layer that contains loads of fat cells and blood vessels, nerves and white blood cells.

Remember, the more you know about the functions of the 11 organ systems, the better you can understand how massage and acupressure work to comfort and encourage healing in your dog.



Text and photos are Copyright © 2013 C. Sue Furman, Ph.D. and Holistic Touch Therapy
c.suefurman@gmail.com

This article originally appeared in the July 2013 edition of the Holistic Touch Therapy Newsletter.