Issue link: https://www.massageandbodyworkdigital.com/i/1519088
The word tissue comes up frequently in our work as massage therapists. Deep-tissue massage. Soft-tissue injury. Scar tissue. But what is a tissue, exactly? Is tissue just another name for the individual structures we've studied, like muscles, ligaments, and bones? Or is there more to it? Let's start with the first question, "What exactly is a tissue?" Tissues are simply a part of the organizing framework biologists use to describe how the body is structured. It goes like this: cells group together to make a tissue; two or more tissues together make an organ; organs together make a body system; and all the systems together make up the whole organism. Thinking in terms of tissues gives us a more refined way to discuss the anatomy we know and some we are less familiar with. Individual, distinct structures are made of multiple tissues, and many tissues lack structural definition but are still affected by our work. Our massage strokes touch all the tissues. TISSUES: THE BODY'S WOVEN FABRIC For a long time, anatomists were limited to studying only what they could see with the naked eye—macrostructures, like organs and muscles. In the early 1600s, when astronomers invented telescopes to zoom in on the cosmos, the same technology helped them create a way to look closely at the human body.¹ Using lenses to manipulate light, scientists crafted the earliest microscopes, paving the way for the new field of microanatomy.² For the first time, microscopes made studying the body at the cellular level possible. Scientists began documenting what cells look like, how they are organized, and how they work together. Teams of collaborating cells were grouped into categories called "tissues" and described as the biological fabrics of the body.³ The anatomical concept of tissue is over 200 years old and derives from tissu, the French word for "fabric." ONE BODY, FOUR TISSUES Every structure we see and touch in the human body contains one or more of four tissue types: epithelial, muscle, nervous, and connective. Let's look at each and see if you recognize them. Epithelial Tissue Epithelial tissue lines the inner and outer surfaces of the body. It's what you see when you look in the mirror and what you touch first in each massage. The skin's epidermis is epithelial, as are the linings of our blood vessels, heart, and even our gut from the mouth all the way to the other end. Epithelial tissues create protective sheets through strongly adhered cells packed together side by side. They create a barrier that determines what is blocked out and what gets through to the deeper layers. Muscle Tissue Muscle tissue powers every heartbeat and step we take. It moves our food through our digestive tract and raises our hair on end when we're frightened. All of this is possible thanks to the muscle tissue's specialized cells that generate the force that powers movement. The capacity to move comes from the protein duo actin and myosin. When stimulated, the two proteins convert chemical energy into movement by reconfiguring their shape and sliding across each other, which shortens the muscle unit and creates a muscle contraction. Nervous Tissue Nervous tissue is specialized to transmit electrochemical impulses that communicate information rapidly to and from the brain and other parts of the body. Highly specialized cells called neurons and a support crew of glial cells make up nervous tissue. Together, neurons and glial cells enable the body to respond to changes in both the external and internal environments and to integrate activities from all the body systems. 72 m a s s a g e & b o d y wo r k m ay/ j u n e 2 0 24 Critical Thinking | Anatomy for Touch Thinking in Tissues A Fresh Perspective on the Anatomy We Touch By Nicole Trombley and Rachelle Clauson KEY POINT • Our bodies comprise four tissue types: epithelial, muscle, nervous, and connective. Your massage strokes touch all of these.