Epimysium (
plural
In many languages, a plural (sometimes list of glossing abbreviations, abbreviated as pl., pl, , or ), is one of the values of the grammatical number, grammatical category of number. The plural of a noun typically denotes a quantity greater than ...
''epimysia'') (Greek ''epi-'' for on, upon, or above + Greek ''mys'' for muscle) is the fibrous tissue envelope that surrounds
muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
.
It is a layer of
dense irregular connective tissue
Dense irregular connective tissue has fibers that are not arranged in parallel bundles as in dense regular connective tissue.
Dense irregular connective tissue has less ground substance than loose connective tissue. Fibroblasts are the predomin ...
which ensheaths the entire
muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
and protects muscles from friction against other muscles and bones.
It also allows a muscle to contract and move powerfully while maintaining its structural integrity.
[ ]
It is continuous with
fascia
A fascia (; : fasciae or fascias; adjective fascial; ) is a generic term for macroscopic membranous bodily structures. Fasciae are classified as superficial, visceral or deep, and further designated according to their anatomical location.
...
and other connective tissue wrappings of muscle including the
endomysium
The endomysium, meaning ''within the muscle'', is a wispy layer of areolar connective tissue that ensheaths each individual muscle fiber, or muscle cell. It also contains capillaries and nerves. It overlies the muscle fiber's cell membrane: th ...
and
perimysium. It is also continuous with tendons, where it becomes thicker and
collagenous
Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a ...
.
While the epimysium is irregular on muscles, it is regular on tendons.
See also
*
Endomysium
The endomysium, meaning ''within the muscle'', is a wispy layer of areolar connective tissue that ensheaths each individual muscle fiber, or muscle cell. It also contains capillaries and nerves. It overlies the muscle fiber's cell membrane: th ...
*
Perimysium
*
Mucous membrane
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...
References
Soft tissue
Muscular system
{{muscle-stub