Epimysium | |
---|---|
Details | |
Location | Muscle |
Identifiers | |
TA98 | A04.0.00.041 |
TA2 | 2009 |
TH | H3.03.00.0.00006 |
FMA | 9726 |
Anatomical terminology |
Epimysium (plural epimysia [1] ) (Greek epi- for on, upon, or above + Greek mys for muscle) is the fibrous tissue envelope that surrounds muscle. [2] It is a layer of dense irregular connective tissue which ensheaths the entire muscle and protects muscles from friction against other muscles and bones. [3] It also allows a muscle to contract and move powerfully while maintaining its structural integrity. [4]
It is continuous with fascia and other connective tissue wrappings of muscle including the endomysium and perimysium. It is also continuous with tendons, where it becomes thicker and collagenous.
While the epimysium is irregular on muscles, it is regular on tendons.
A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as articular ligament, articular larua, fibrous ligament, or true ligament. Other ligaments in the body include the:
A skeleton is the structural frame that supports the body of most animals. There are several types of skeletons, including the exoskeleton, which is a rigid outer shell that holds up an organism's shape; the endoskeleton, a rigid internal frame to which the organs and soft tissues attach; and the hydroskeleton, a flexible internal structure supported by the hydrostatic pressure of body fluids.
In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system.
Flesh is any aggregation of soft tissues of an organism. Various multicellular organisms have soft tissues that may be called "flesh". In mammals, including humans, flesh encompasses muscles, fats and other loose connective tissues, but sometimes excluding non-muscular organs and typically discarded parts. More generally, it may be considered the portions of the body that are soft and delicate. In a culinary context, consumable animal flesh is called meat, while processed visceral tissues are known as offal.
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesoderm, the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord, are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells. Blood, and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leukocytes.
A fascia 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.
Striated muscle tissue is a muscle tissue that features repeating functional units called sarcomeres. The presence of sarcomeres manifests as a series of bands visible along the muscle fibers, which is responsible for the striated appearance observed in microscopic images of this tissue. There are two types of striated muscle:
A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur close enough to the epidermis such that the bleeding causes a visible discoloration. The bruise then remains visible until the blood is either absorbed by tissues or cleared by immune system action. Bruises which do not blanch under pressure can involve capillaries at the level of skin, subcutaneous tissue, muscle, or bone.
The periosteum is a membrane that covers the outer surface of all bones, except at the articular surfaces of long bones. Endosteum lines the inner surface of the medullary cavity of all long bones.
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: the sarcolemma. Endomysium is the deepest and smallest component of muscle connective tissue. This thin layer helps provide an appropriate chemical environment for the exchange of calcium, sodium, and potassium, which is essential for the excitation and subsequent contraction of a muscle fiber.
Perimysium is a sheath of dense irregular connective tissue that groups muscle fibers into bundles or fascicles.
In anatomy, the masseter is one of the muscles of mastication. Found only in mammals, it is particularly powerful in herbivores to facilitate chewing of plant matter. The most obvious muscle of mastication is the masseter muscle, since it is the most superficial and one of the strongest.
Dense connective tissue, also called dense fibrous tissue, is a type of connective tissue with fibers as its main matrix element. The fibers are mainly composed of type I collagen. Crowded between the collagen fibers are rows of fibroblasts, fiber-forming cells, that generate the fibers. Dense connective tissue forms strong, rope-like structures such as tendons and ligaments. Tendons attach skeletal muscles to bones; ligaments connect bones to bones at joints. Ligaments are more stretchy and contain more elastic fibers than tendons. Dense connective tissue also make up the lower layers of the skin (dermis), where it is arranged in sheets. In addition, the sclera contains dense connective tissue
The nuchal ligament is a ligament at the back of the neck that is continuous with the supraspinous ligament.
Equine anatomy encompasses the gross and microscopic anatomy of horses, ponies and other equids, including donkeys, mules and zebras. While all anatomical features of equids are described in the same terms as for other animals by the International Committee on Veterinary Gross Anatomical Nomenclature in the book Nomina Anatomica Veterinaria, there are many horse-specific colloquial terms used by equestrians.
A muscle fascicle is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue.
The perineurium is a protective sheath that surrounds a nerve fascicle. This bundles together axons targeting the same anatomical location. The perineurium is composed from fibroblasts.
A pennate or pinnate muscle is a type of skeletal muscle with fascicles that attach obliquely to its tendon. This type of muscle generally allows higher force production but a smaller range of motion. When a muscle contracts and shortens, the pennation angle increases.
A key component in lateral force transmission in skeletal muscle is the extracellular matrix (ECM). Skeletal muscle is a complex biological material that is composed of muscle fibers and an ECM consisting of the epimysium, perimysium, and endomysium. It can be described as a collagen fiber-reinforced composite. The ECM has at least three functions: (1) to provide a framework binding muscle fibers together and ensure their proper alignment, (2) to transmit the forces, either from active muscle contraction or ones passively imposed on it, and (3) providing lubricated surfaces between muscle fibers and bundles enabling the muscle to change shape. The mechanical properties of skeletal muscle depend on both the properties of muscle fibers and the ECM, and the interaction between the two. Contractile forces are transmitted laterally within intramuscular connective tissue to the epimysium and then to the tendon. Due to the nature of skeletal muscle, direct measurements are not possible, but many indirect studies and analyses have shown that the ECM is an important part of force transmission during muscle contraction.
Anatomical terminology is used to uniquely describe aspects of skeletal muscle, cardiac muscle, and smooth muscle such as their actions, structure, size, and location.