How cardiac muscle fibers differ from the fibrs of skeletal muscle?

Cardiac muscle fibers differ from the fibers of skeletal muscle in several key ways:

- Location: Cardiac muscle fibers are located only in the heart, while skeletal muscle fibers are found throughout the body.

- Structure: Cardiac muscle fibers are branched and interconnected by intercalated discs, which allow for the rapid spread of electrical impulses throughout the heart. Skeletal muscle fibers are long and cylindrical and do not have intercalated discs.

- Contraction: Cardiac muscle fibers contract involuntarily and rhythmically, while skeletal muscle fibers contract voluntarily.

- Duration of contraction: Cardiac muscle fibers contract for a longer period of time than skeletal muscle fibers.

- Energy source: Cardiac muscle fibers primarily use fatty acids as an energy source, while skeletal muscle fibers use a combination of glucose and fatty acids.

- Innervation: Cardiac muscle fibers are innervated by the autonomic nervous system, while skeletal muscle fibers are innervated by the somatic nervous system.

- Troponin: Cardiac muscle fibers contain a unique form of troponin, which is responsible for regulating muscle contraction. Skeletal muscle fibers contain a different form of troponin.

- Myosin: Cardiac muscle fibers contain a unique form of myosin, which is responsible for generating force during muscle contraction. Skeletal muscle fibers contain a different form of myosin.

These differences in structure and function allow cardiac muscle to function properly and efficiently, pumping blood throughout the body.