Human muscle system | Functions, Diagram, & Facts | Britannica
2024年10月21日 · Human muscle system, the muscles of the human body that work the skeletal system, that are under voluntary control, and that are concerned with movement, posture, and balance. Broadly considered, human muscle—like the muscles of all vertebrates—is often divided into striated muscle, smooth muscle, and cardiac muscle.
Muscle | Systems, Types, Tissue, & Facts | Britannica
2024年10月16日 · Muscle powers the movements of multicellular animals and maintains posture. Its gross appearance is familiar as meat or as the flesh of fish. Muscle is the most plentiful tissue in many animals; for example, it makes up 50 to 60 percent of the body mass in many fishes and 40 to 50 percent in antelopes.
Muscle - Structure, Organization, Fibers | Britannica
2024年10月16日 · Muscle - Structure, Organization, Fibers: Smooth muscle contains spindle-shaped cells 50 to 250 μm in length by 5 to 10 μm in diameter. These cells possess a single, central nucleus. Surrounding the nucleus and throughout most of the cytoplasm are the thick (myosin) and thin (actin) filaments.
Skeletal muscle | Definition & Function | Britannica
2024年10月19日 · Skeletal muscle, in vertebrates, the type of muscle that is attached to bones by tendons and that produces all the movements of body parts in relation to each other.
Cardiac muscle | Definition, Function, & Structure | Britannica
2024年10月19日 · Cardiac muscle, in vertebrates, one of three major muscle types, found only in the heart. Cardiac muscle possesses contractile units known as sarcomeres and exhibits rhythmic contractions. The rhythmic contractions are regulated by the sinoatrial node of the heart and thus are not under voluntary control.
Human body | Organs, Systems, Structure, Diagram, & Facts
2024年11月12日 · The musculoskeletal system (also referred to separately as the muscle system and the skeletal system), composed of the skeletal muscles and bones (with about 206 of the latter in adults), moves the body and protectively houses its internal organs.
Muscle - Types, Structure, Function | Britannica
2024年10月16日 · The principal types of muscles are striated muscle, in which the filaments are organized in transverse bands as in Figure 2; obliquely striated muscle, in which the filaments are staggered, making the bands oblique (Figure 3); and smooth muscle, in which the filaments are arranged irregularly.
Tendon | Description & Function | Britannica
Tendon, tissue that attaches a muscle to other body parts, usually bones. Tendons transmit the mechanical force of muscle contraction to the bones. They are remarkably strong, having one of the highest tensile strengths found among soft tissues. …
Human skeleton | Parts, Functions, Diagram, & Facts | Britannica
2024年10月23日 · When one considers the relation of these subdivisions of the skeleton to the soft parts of the human body—such as the nervous system, the digestive system, the respiratory system, the cardiovascular system, and the voluntary muscles of the muscle system—it is clear that the functions of the skeleton are of three different types: support ...
Human muscle system - Shoulder Muscles, Joints, Movements
2024年10月21日 · Human muscle system - Shoulder Muscles, Joints, Movements: The shoulder is a complex ball-and-socket joint comprising the head of the humerus, the clavicle (collarbone), and the scapula. The shoulder’s main motions are flexion, extension, abduction, adduction, internal rotation, and external rotation.