A muscle is a tissue composed of bundles of specialized cells that, when stimulated by nerve impulses, contract and produce movement.
An organ which by contraction produces movement of an organism. There are three types: striated, cardiac, and smooth.
An organ in the body, which contracts to make part of the body.
Type of contractile tissue, composed of fibers that can contract, causing movement of parts and organs. There are three basic kinds of muscle: skeletal muscle, which is striated in appearance, controls voluntary movement, responds quickly to neural stimulation, and is paralyzed if innervation is lost; smooth muscle, which is not striped in appearance, comprises the musculature of all visceral organs, responds slowly to stimulation, and controls involuntary movement; and cardiac muscle, which is striped in appearance, but does not respond as quickly as skeletal muscle and continues to contract if it loses its neural stimuli.
A fibrous structure in the body composed of cells that can contract or relax to generate movement. Different types of muscles can cause movement of the skeletal framework of the body (skeletal muscle), movement of the tissues of body organs (smooth muscle), or the specialized pumping action of the heart (cardiac muscle). The skeletal muscles, attached to bone, make up slightly less than half of the total body weight of an average person.
A tissue whose cells have the ability to contract, producing movement or force. Muscles possess mechanisms for converting energy derived from chemical reactions into mechanical energy. The major functions of muscles are to produce movements of the body, to maintain the position of the body against the force of gravity, to produce movements of structures inside the body, and to alter pressures or tensions of structures in the body. There are three types of muscle: striated muscle, attached to the skeleton; smooth muscle, which is found in such tissues as the stomach, gut, and blood vessels; and cardiac muscle, which forms the walls of the heart.
Muscular tissue is divided, according to its function, into three main groups: voluntary muscle, involuntary muscle, and skeletal muscle of which the first is under control of the will, whilst the latter two discharge their functions independently. The term ‘striped muscle is often given to voluntary muscle because, under the microscope all the voluntary muscles show a‘ striped appearance, whilst involuntary muscle is, in the main, unstriped or plain. Heart muscle is partially striped, while certain muscles of the throat, and two small muscles inside the ear, not controllable by willpower, are also striped.
A type of tissue composed of contractile cells or fibers that effects movement of an organ or part of the body. The outstanding characteristic of muscular tissue is its ability to shorten or contract. It also possesses the properties of irritability, conductivity, and elasticity. Muscle tissue possesses little intercellular material; hence, its cells or fibers lie close together.
A structure composed of bundles of specialized cells that, when stimulated by nerve impulses, contract and produce movement.
The human anatomy encompasses a intricate system comprised of muscles which necessitate a substantial amount of energy for movement and functionality. These muscles hoard glycogen and indispensable fatty acids that are later metabolized for energy utilization.
A muscle is made up of groups of specialized cells that can contract and relax, producing movement. There are three kinds of muscles: skeletal, smooth, and cardiac.
Skeletal muscles are the most dominant muscle type in the body and are referred to as voluntary muscles since they operate under conscious control.
Skeletal muscles consist of muscle fibers grouped into bundles known as fascicles. Each fiber contains longitudinal structures called myofibrils. These myofibrils operate with actin and myosin filaments, two proteins responsible for contraction. When the brain sends impulses, the myosin filaments glide over the actin, causing the muscle fibers to contract and produce movement. At the same time, nerve fibers in the muscle detect the contraction strength, while those in the tendon gauge its stretch. This feedback is sent to the brain, which moderates the contraction intensity. The function of the muscle is influenced by the chemical makeup of the fluid surrounding its cells. A drop in potassium ion levels results in muscle weakness, whereas a reduction in calcium ion levels can lead to muscle spasms.
Muscles continuously maintain a state of slight contraction, known as muscle tone, even when they are at rest. Certain disorders can lead to abnormalities in muscle tone, resulting in either extreme stiffness (spasticity) or laxness (hypotonia).
This kind of muscle is found in the walls of internal organs. It facilitates movements like the intestine’s peristalsis and the uterus’s contractions during childbirth. Smooth muscle is also a component of the lining in hollow entities like blood vessels, air passages, and the bladder. Often referred to as involuntary muscle, it operates without conscious command.
The muscle consists of elongated, spindle-shaped cells and contracts through the interaction of actin and myosin, similar to skeletal muscle. It’s activated by the autonomic nervous system but also reacts to hormones and chemical concentrations surrounding the muscle.
The myocardium, also known as cardiac muscle, is exclusively located in the heart. This muscle has the unique ability to contract in a consistent and rhythmic manner, approximately 100,000 times every day. The contractions are influenced by the autonomic nervous system, hormones, and the expansion of the muscle fibers. The primary electrical trigger originates from the sinoatrial node and is disseminated through specialized conduction cells spread throughout the muscle fibers. These fibers are interconnected at their ends by expansive folded regions, allowing for swift transmission of contractions from one fiber to the next.
The most frequent issues with muscles are injuries and insufficient blood circulation to them.