The key difference between epimysium and fascia is that epimysium is the connective tissue that surrounds a single muscle while fascia is the connective tissue that attaches, stabilizes, encloses, and separates muscles and other internal organs.
Connective tissue is one of the four types of tissues we have in our body. It is located between all the other tissues. Therefore, it is the most abundant and widely distributed tissue. Fascia and epimysium are two types of connective tissues. Epimysium is the connective tissue that surrounds an entire muscle. Fascia is the connective tissue that is on the epimysium surrounding and separating muscles. Epimysium is continuous with the fascia.
CONTENTS
1. Overview and Key Difference
2. What is Epimysium
3. What is Fascia
4. Similarities Between Epimysium and Fascia
5. Side by Side Comparison – Epimysium vs Fascia in Tabular Form
6. Summary
What is Epimysium?
Skeletal muscle is one of the three types of muscles. Skeletal muscles help bones and other structures for their movements. These muscles are composed of long bundles of cells called muscle fibers or myocytes. Muscle fibers are composed of thousands of myofibrils. Epimysium, perimysium and endomysium are three connective tissues that cover different parts of the skeletal muscle. Endomysium surrounds each muscle fiber or muscle cell while perimysium ensheaths a bundle of muscle fibers or fascicles.
Figure 01: Epimysium
Epimysium surrounds the entire skeletal muscle. Therefore, epimysium is the connective tissue that wraps the entire muscle. Structurally, it is a dense irregular connective tissue that is fibrous and elastic. It is continuous with fascia and other connective tissues that surround muscles. Moreover, it is continuous with tendons. But in tendons, epimysium becomes thicker and collagenous. The main function of epimysium is the protection of muscles from friction against other muscles and bones.
What is Fascia?
Fascia is an important structure in our body. It provides a framework for all connective tissues. We can find fascia everywhere in our body, from head to toe, without interruption. A fibrous connective tissue makes the fascia. There are loosely packed collagen bundles in the fascia. There are three different kinds of fascia as superficial fascia, deep fascia and visceral fascia.
Superficial Fascia
Superficial fascia lies just beneath the dermis of the skin. In fact, it is the lowermost layer of the skin. it consists of loose connective tissue and adipose tissue. There are collagen and elastin fibres. Hence, superficial fascia is more extensible than the other two fasciae. Superficial fascia has two layers: top layer and bottom layer. The top layer is a fatty layer which stores fat. Deep layer or bottom layer of superficial fascia lies just above the deep fascia. Arteries, veins, nerves, lymph vessels and nodes run through this bottom layer of the superficial fascia. Superficial fascia has several functions. It works as a storage tissue of water and fat and acts as an insulation layer. Moreover, it also provides pathways to nerves and blood vessel and, protects the internal structures from the mechanical damages, providing protective padding. Most importantly, superficial fascia is responsible for creating the shape of the body.
Figure 02: Fascia
Deep Fascia
Deep fascia is a fibrous membrane that surrounds each and every muscle in our body and separate muscle groups into compartments. It is the most extensive of the three types of fascia. It consists of dense connective tissue. Therefore, it is a fibrous layer that surrounds individual muscles and groups of muscles into functional compartments. Similar to the superficial fascia, deep fascia also contains high dense collagen and elastin fibres. But, the deep fascia is less extensible than the superficial fascia.
Deep fascia provides an extra surface for muscle attachment. Moreover, it keeps the underlying structures of our body in position. Furthermore, deep fascia helps muscles in their action by tolerating tension and pressure.
Visceral Fascia
Visceral fascia is the third type and it wraps the organs suspending within their cavities with layers of connective tissue membranes. The pericardium is one of the visceral fascia. Compared to the superficial fascia, visceral fascia is less extensible.
What are the Similarities Between Epimysium and Fascia?
- Both epimysium and fascia are connective tissues.
- They wrap muscles in our body.
- They are rich in collagen fibers.
- Epimysium is continuous with fascia and other connective tissue.
- They protect muscles and other organs.
What is the Difference Between Epimysium and Fascia?
Epimysium is the dense irregular connective tissue that wraps a whole muscle. Meanwhile, fascia is a connective tissue that surrounds muscles, groups of muscles, blood vessels, and nerves, and binding those structures together. So, this the key difference between epimysium and fascia. Also, epimysium is found below the fascia in skeletal muscles, but fascia is found beneath the skin and over the epimysium of skeletal muscles.
Moreover, another significant difference between epimysium and fascia is their function. That is; the epimysium protects muscles from friction against other muscles and bones, while the fascia provides support for surrounding tissues, reduces friction, and plays a supportive role for the tissues and organs.
Summary – Epimysium vs Fascia
Epimysium is a connective tissue that wraps a muscle. It protects the muscle from friction against other muscles and organs. On the other hand, fascia is the connective tissue that provides a framework for all tissues and organs in our body. It is found beneath the skin and over the epimysium in muscles. Hence, epimysium is continuous with fascia. So, this is the summary of the difference between epimysium and fascia.
Reference:
1. “Fascia.” Wikipedia, Wikimedia Foundation, 8 Oct. 2019, Available here.
2. Gatt, Adrianna. “Anatomy, Fascia Layers.” StatPearls [Internet]., U.S. National Library of Medicine, 30 July 2019, Available here.
Image Courtesy:
1. “Illu muscle structure” (Public Domain) via Commons Wikimedia
2. “Gray395” By Henry Vandyke Carter – Henry Gray (1918) Anatomy of the Human Body (See “Book” section below)Bartleby.com: Gray’s Anatomy, Plate 395 (Public Domain) via Commons Wikimedia