Types of Human muscle tissues | skeletal, cardiac, and smooth muscles

Structure of skeletal muscle | how muscle is
attached to the bone by means of tendons

There are three general types of muscle tissues:

• Skeletal muscle responsible for movement
• Cardiac muscle responsible for pumping blood
• Smooth muscle responsible for sustained contractions in the blood vessels, gastrointestinal tract, and other areas in the body

Skeletal and cardiac muscles are called striated muscle because of their striped appearance under a microscope, which is due to the highly organized alternating pattern of A band and I band.

Skeletal Muscles

skeletal muscles are the form of striated muscles. they are under the control of the somatic nervous system. these are the voluntary muscles meaning that they are under the control of the human...most skeletal muscles are attached to the bones by means of tendons..

Skeletal muscles are made up of individual components known as muscle fibers. These muscles fibers are formed by the fusion of developmental myoblasts

muscle fibers are long cylindrical and multinucleated cells which are composed of myofibrils. The myofibrils are composed of actin and myosin myofibrils..the basic functional unit of the muscle fiber and responsible for skeletal muscle's striated appearance and forming the basic machinery necessary for muscle contraction.

Classification of Muscle fibers according to colour:

Red Fibers: Those muscle fibers containing high levels of myoglobin and oxygen storing proteins had a red appearance. Red muscle fibers tend to have more mitochondria and greater local capillary density.

White Fibers: Those muscle fibers with a low content had a white appearance.
As more was learned about the functional differences between skeletal muscle fibers, they were also classified, depending on their twitch capabilities, into fast and slow twitch, traits that largely, but not completely, overlap the previous classification based on color.

Classification of Muscle fibers according to twitch:

Fast Twitch: Fast twitch fiber are one in which the myosin can split ATP very quickly.
However, fast twitch fibers also demonstrate a higher capability for electrochemical transmission of action potentials and a rapid level of calcium release and uptake by the sarcoplasmic reticulum.
The fast twitch fibers rely on a well-developed, short term, glycolytic system for energy transfer and can contract and develop tension at 2-3 times the rate of slow twitch fibers.

Slow Twitch: The slow twitch fibers generate energy for ATP re-synthesis by means of a long term system of aerobic energy transfer. They tend to have a low activity level of ATPase, a slower speed of contraction with a less well developed glycolytic capacity. They contain large and numerous mitochondria and with the high levels of myoglobin that gives them a red pigmentation. They have been demonstrated to have high concentration of mitochondrial enzymes, thus they are fatigue resistant.

Muscle Contraction:

Muscle Fibers are composed of actin and myosin which generate tension in the muscle fibers.. under tension muscle may become long , short, or remain same. although muscle contraction means shortening of the muscle fiber but when it refers to the muscle it means generating tension by the action of the actin and myosin with the help of the motor neurons.

Voluntary muscle contraction is controlled by the central nervous system. The brain sends signals, in the form of action potentials, through the nervous system to the motor neuron that innervates several muscle fibers.