"kidney-shaped; its circumference is grooved, for the tarsometatarsal ligaments, and medially gives insertion to part of the tendon of the tibialis anterior. The body of the bone is strong, and of well-marked prismoid form. The head is large; on its plantar surface are two grooved facets on which the sesamoid bones glide; the facets are separated by a smooth elevation. Three muscles attach to the first metatarsal bone: the tibialis anterior, fibularis longus and first dorsal interosseus. The tibialis anterior inserts at the basis of the bone, while the fibularis longus inserts at the tuberosity. The lateral part of the"
"to bones. The extra-cellular connective tissue between muscle fibers binds to tendons at the distal and proximal ends, and the tendon binds to the periosteum of individual bones at the muscle's origin and insertion. As muscles contract, tendons transmit the forces to the relatively rigid bones, pulling on them and causing movement. Tendons can stretch substantially, allowing them to function as springs during locomotion, thereby saving energy. Joints are structures that connect individual bones and may allow bones to move against each other to cause movement. There are three divisions of joints, diarthroses which allow extensive mobility between two or"
"to muscles. Synovial membranes are found in joint capsules, where they contain synovial fluid, which lubricates joints. Bones are covered by a tough membrane called periosteum, which covers the entire bone excluding areas of articulation. Ligaments attach bone to bone, and are vital in stabilizing joints as well as supporting structures. They are made up of fibrous material that is generally quite strong. Due to their relatively poor blood supply, ligament injuries generally take a long time to heal. Ligaments of the upper body include: Ligaments of the legs include: The axial skeleton contains the skull, vertebral column, sternum, and"
"Ligament 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: Ligaments are similar to tendons and fasciae as they are all made of connective tissue. The differences in them are in the connections that they make: ligaments connect one bone to another bone, tendons connect muscle to bone, and fasciae connect muscles to other muscles. These are all found in the skeletal system of the human body. Ligaments cannot usually be regenerated naturally; however, there"
"Tendon A tendon or sinew is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments; both are made of collagen. Ligaments join one bone to bone, while tendons connect muscle to bone for a proper functioning of the body. Histologically, tendons consist of dense regular connective tissue fascicles encased in dense irregular connective tissue sheaths. Normal healthy tendons are composed mostly of parallel arrays of collagen fibers closely packed together. They are anchored to bone by Sharpey's fibres. The dry mass of normal tendons, which"
"system for calcium and phosphorus and contains critical components of the hematopoietic system. This system describes how bones are connected to other bones and muscle fibers via connective tissue such as tendons and ligaments. The bones provide stability to the body. Muscles keep bones in place and also play a role in the movement of bones. To allow motion, different bones are connected by joints. Cartilage prevents the bone ends from rubbing directly onto each other. Muscles contract to move the bone attached at the joint. There are, however, diseases and disorders that may adversely affect the function and overall"
"unit of skeletal muscle. The sarcomere is a highly structured protein array, consisting of interdigitating thick and thin filaments, where the thin filaments are tethered to a protein structure, the Z-line. The dynamic interaction between the thick and thin filaments results in muscle contraction. Myosin belongs to a family of motor proteins, and the muscle isoforms of this family comprise the thick filament. The thin filament is made of the skeletal muscle isoforms of actin. Each myosin protein 'paddles' along the thin actin filament, repeatedly binding to myosin-binding sites along the actin filament, ratcheting and letting go. In effect, the"
"the muscle fiber, the surface layer of the sarcolemma fuses with a tendon fiber, and the tendon fibers, in turn, collect into bundles to form the muscle tendons that adhere to bones. The sarcolemma generally maintains the same function in muscle cells as the plasma membrane does in other eukaryote cells. It acts as a barrier between the extracellular and intracellular compartments, defining the individual muscle fiber from its surroundings. The lipid nature of the membrane allows it to separate the fluids of the intra- and extracellular compartments, since it is only selectively permeable to water through aquaporin channels. As"
"the tissue linking the structures is ligamentous. A gomphosis is a specialized fibrous joint in which a conical process or peg of one bone fits into a hole or socket in another bone. (gomphos is a Greek word meaning bolt). Small quantity of fibrous tissue holds the bones together. No movement is possible at such peg-and-socket joints. Fibrous joint Fibrous joints are connected by dense connective tissue, consisting mainly of collagen. These are fixed joints where bones are united by a layer of white fibrous tissue of varying thickness. In the skull the joints between the bones are called sutures."
"ornithischian dinosaurs, ossified axial muscle tendons form a latticework along the neural and haemal spines on the tail, presumably for support. Tendon A tendon or sinew is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments; both are made of collagen. Ligaments join one bone to bone, while tendons connect muscle to bone for a proper functioning of the body. Histologically, tendons consist of dense regular connective tissue fascicles encased in dense irregular connective tissue sheaths. Normal healthy tendons are composed mostly of parallel arrays"
"EMG recordings during the main experimental testing for that same skeletal muscle. B. K. Pedersen and her colleagues have conducted research showing that skeletal muscle functions as an endocrine organ by secreting cytokines and other peptides, now referred to as myokines. Myokines in turn are believed to mediate the health benefits of exercise. Skeletal muscle Skeletal muscle is one of three major muscle types, the others being cardiac muscle and smooth muscle. It is a form of striated muscle tissue, which is under the voluntary control of the somatic nervous system. Most skeletal muscles are attached to bones by bundles"
"the site of attachment of bones with tendons or ligaments. Relatedly, in muscle terminology, the insertion is the site of attachment at the end with predominant movement or action (opposite of the origin). Thus the words (""enthesis"" and ""insertion"" [of muscle]) are proximal in the semantic field, but ""insertion"" in reference to muscle can refer to any relevant aspect of the site (i.e., the attachment per se, the bone, the tendon, or the entire area), whereas ""enthesis"" refers to the attachment per se and to ligamentous attachments as well as tendinous ones. Enthesis The enthesis (plural entheses) is the connective"
"tendons. In turn, the tendons connect to the periosteum layer surrounding the bones, permitting the transfer of force from the muscles to the skeleton. Together, these fibrous layers, along with tendons and ligaments, constitute the deep fascia of the body. The muscular system consists of all the muscles present in a single body. There are approximately 650 skeletal muscles in the human body, but an exact number is difficult to define. The difficulty lies partly in the fact that different sources group the muscles differently and partly in that some muscles, such as palmaris longus, are not always present. A"
"This may be a bone, a tendon or the subcutaneous dermal connective tissue. Insertions are usually connections of muscle via tendon to bone. The insertion is a bone that tends to be distal, have less mass, and greater motion than the origin during a contraction. Muscles may also be described by the direction that the muscle fibres run in. Hypertrophy is increase in muscle size from an increase in size of individual muscle cells. This usually occurs as a result of exercise. Anatomical terms of muscle Muscles are described using unique anatomical terminology according to their actions and structure. There"
"bone growth, cellular signalling, blood clotting, muscle contraction and neuron function. Calcium is one of the essential components of bone, contributing to its strength and structure in addition to being the main site at which it is stored within the body. Within the muscles, its primary use is to enable contractions. Muscle cells draw calcium from the blood, allowing it to bind with troponin, a component of the muscle fibre that signals for a contraction by moving actin and myosin. After a contraction, calcium dissipates and the filaments move back to a resting state before the release of more calcium"
"Skeletal muscle Skeletal muscle is one of three major muscle types, the others being cardiac muscle and smooth muscle. It is a form of striated muscle tissue, which is under the voluntary control of the somatic nervous system. Most skeletal muscles are attached to bones by bundles of collagen fibers known as tendons. A skeletal muscle refers to multiple bundles (fascicles) of cells joined together called muscle fibers. The fibres and muscles are surrounded by connective tissue layers called fasciae. Muscle fibres, or muscle cells, are formed from the fusion of developmental myoblasts in a process known as myogenesis. Muscle"
"Bone A bone is a rigid organ that constitutes part of the vertebrate skeleton. Bones support and protect the various organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility. Bones come in a variety of shapes and sizes and have a complex internal and external structure. They are lightweight yet strong and hard, and serve multiple functions. Bone tissue (osseous tissue) is a hard tissue, a type of dense connective tissue. It has a honeycomb-like matrix internally, which helps to give the bone rigidity. Bone tissue is"
"muscle tissue approximately 15% denser than fat tissue. Skeletal muscles are sheathed by a tough layer of connective tissue called the epimysium. The epimysium anchors muscle tissue to tendons at each end, where the epimysium becomes thicker and collagenous. It also protects muscles from friction against other muscles and bones. Within the epimysium are multiple bundles called fascicles, each of which contains 10 to 100 or more muscle fibers collectively sheathed by a perimysium. Besides surrounding each fascicle, the perimysium is a pathway for nerves and the flow of blood within the muscle. The threadlike muscle fibers are the individual"
"called focal adhesions) in the cell membrane of the smooth muscle cell, called the sarcolemma. The adherens junctions consist of large number of proteins including α-actinin, vinculin and cytoskeletal actin. The adherens junctions are scattered around ""dense bands"" that are circumfering the smooth muscle cell in a rib-like pattern. The dense band (or dense plaques) areas alternate with regions of membrane containing numerous caveolae. When complexes of actin and myosin contract, force is transduced to the sarcolemma through intermediate filaments attaching to such dense bands. During contraction, there is a spatial reorganization of the contractile machinery to optimize force development."
"and acid-base status in the whole organism. The functional part of bone, the ""bone matrix"", is entirely extracellular. The bone matrix consists of protein and mineral. The protein forms the ""organic matrix."" It is synthesized and then the mineral is added. The vast majority of the organic matrix is collagen, which provides tensile strength. The matrix is mineralized by deposition of hydroxyapatite (alternative name, hydroxylapatite). This mineral is hard, and provides compressive strength. Thus, the collagen and mineral together are a composite material with excellent tensile and compressive strength, which can bend under a strain and recover its shape without"
"smooth muscles. Neuromuscular junctions are the focal point where a motor neuron attaches to a muscle. Acetylcholine, (a neurotransmitter used in skeletal muscle contraction) is released from the axon terminal of the nerve cell when an action potential reaches the microscopic junction called a synapse. A group of chemical messengers cross the synapse and stimulate the formation of electrical changes, which are produced in the muscle cell when the acetylcholine binds to receptors on its surface. Calcium is released from its storage area in the cell's sarcoplasmic reticulum. An impulse from a nerve cell causes calcium release and brings about"
"rays and, except for the caudal fin, have no direct connection with the spine. They are supported only by the muscles. The ribs attach to the spine. Bones are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue. Bones come in a variety of shapes and have a complex internal and external structure. They are lightweight, yet strong and hard, in addition to fulfilling their many other functions."
"which forms the thick filament, and actin, which forms the thin filament. Myosin has a long, fibrous tail and a globular head, which binds to actin. The myosin head also binds to ATP, which is the source of energy for muscle movement. Myosin can only bind to actin when the binding sites on actin are exposed by calcium ions. Actin molecules are bound to the Z line, which forms the borders of the sarcomere. Other bands appear when the sarcomere is relaxed. A muscle fiber from a biceps muscle may contain 100,000 sarcomeres. The myofibrils of smooth muscle cells are"
"are intricately woven and endlessly remodeled by a group of specialized bone cells. Their unique composition and design allows bones to be relatively hard and strong, while remaining lightweight. Bone matrix is 90 to 95% composed of elastic collagen fibers, also known as ossein, and the remainder is ground substance. The elasticity of collagen improves fracture resistance. The matrix is hardened by the binding of inorganic mineral salt calcium phosphate in a chemical arrangement known as calcium hydroxylapatite. It is the bone mineralization that give bones rigidity. Bone is actively constructed and remodeled throughout life by special bone cells known"
"are bundles of contractile fibers that are attached to bones by tendons. These bundles have different types of fibers within them, and horses have adapted over the years to produce different amounts of these fibers. Type II-b fibers are fast twitch fibers. These fibers allow muscles to contract quickly, resulting in a great deal of power and speed. Type I fibers are slow-twitch fibers. They allow muscles to work for longer periods of time resulting in greater endurance. Type II-a fibers are intermediate, representing a balance between the fast-twitch fibers and the slow-twitch fibers. They allow the muscles to generate"
"bones. The bone tissue is arranged either in a compact or trabecular pattern and composed of organized structures that vary in length from the centimeter range all the way to the nanometer scale. Nonmineralized organic component (i.e. type 1 collagen), mineralized inorganic component (i.e. hydroxyapatite), and many other noncollagenous matrix proteins (i.e. glycoproteins and proteoglycans) make up the nanocomposite structure of the bone ECM. The organic collagen fibers and the inorganic mineral salts provide flexibility and toughness, respectively, to ECM. Although the bone is a dynamic tissue that can self-heal upon minor injuries, it cannot regenerate after experiencing large defects"
"not arranged into sarcomeres. The sarcomeres are what give skeletal and cardiac muscles their striated appearance, which was first described by Leeuwenhoek. The relationship between the proteins and the regions of the sarcomere are as follows: Upon muscle contraction, the A-bands do not change their length (1.85 micrometer in mammalian skeletal muscle), whereas the I-bands and the H-zone shorten. This causes the Z lines to come closer together. The protein [tropomyosin] covers the myosin binding sites of the actin molecules in the muscle cell. To allow the muscle cell to contract, tropomyosin must be moved to uncover the binding sites"
"Scapula In anatomy, the scapula (plural scapulae or scapulas), also known as shoulder bone, shoulder blade, wing bone or blade bone, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones the scapulae are paired, with the scapula on either side of the body being roughly a mirror image of the other. The name derives from early Roman times when it was thought that the bone resembled a trowel or small shovel. In compound terms, the prefix omo- is used for the shoulder blade in Latin medical terminology. The prefix is"
"set of fibers that perform the same function, and are usually supplied by different nerves for different set of fibers. For example, the tongue itself is a composite muscle made up of various components like longitudinal, transverse, horizontal muscles with different parts innervated having different nerve supply. The ""insertion"" and ""origin"" of a muscle are the two places where it is anchored, one at each end. The tissue of the attachment is called an ""enthesis"". The ""origin"" of a muscle is the bone, typically proximal, which has greater mass and is more stable during a contraction than a muscle's insertion."
"to keep warm. Skeletal muscles, like other striated muscles, are composed of myocytes, or muscle fibers, which are in turn composed of myofibrils, which are composed of sarcomeres, the basic building block of striated muscle tissue. Upon stimulation by an action potential, skeletal muscles perform a coordinated contraction by shortening each sarcomere. The best proposed model for understanding contraction is the sliding filament model of muscle contraction. Within the sarcomere, actin and myosin fibers overlap in a contractile motion towards each other. Myosin filaments have club-shaped heads that project toward the actin filaments. Larger structures along the myosin filament called"
"its axis. In addition to the actin and myosin components that constitute the sarcomere, skeletal muscle fibers also contain two other important regulatory proteins, troponin and tropomyosin, that are necessary for muscle contraction to occur. These proteins are associated with actin and cooperate to prevent its interaction with myosin. Skeletal muscle cells are excitable and are subject to depolarization by the neurotransmitter acetylcholine, released at the neuromuscular junction by motor neurons. Once a cell is sufficiently stimulated, the cell's sarcoplasmic reticulum releases ionic calcium (Ca2+), which then interacts with the regulatory protein troponin. Calcium-bound troponin undergoes a conformational change that"
"to their fine and complex structure. A ""sinus"" refers to a bony cavity, usually within the skull. A joint, or articulation is the region where adjacent bones contact each other, for example the elbow, shoulder, or costovertebral joint. Terms that refer to joints include: Bones are commonly described with the terms ""head"", ""neck"", ""shaft"", ""body"" and ""base"" The ""head"" of a bone usually refers to the proximal end of the bone. The shaft refers to the elongated sections of long bone, and the ""neck"" the segment between the head and shaft (or body). The end of the long bone opposite"
"Fibrous joint Fibrous joints are connected by dense connective tissue, consisting mainly of collagen. These are fixed joints where bones are united by a layer of white fibrous tissue of varying thickness. In the skull the joints between the bones are called sutures. Such immovable joints are also referred to as synarthroses. Most fibrous joints are also called ""fixed"" or ""immovable"". These joints have no joint cavity and are connected via fibrous connective tissue. The skull bones are connected by fibrous joints called sutures. In fetal skulls the sutures are wide to allow slight movement during birth. They later become"