What is a "fascicle"?

A fascicle refers to a bundle or group of individual muscle fibers, nerve fibers, or other similar structures that are bound together by connective tissue. In the context of muscles, fascicles are the basic structural units that make up a muscle. They are surrounded by a layer of connective tissue called perimysium, which provides support and protection. Within each fascicle, individual muscle fibers, or myocytes, run parallel to each other. The fascicles work together to transmit the force generated by the muscle contraction. In the case of nerves, fascicles consist of bundles of nerve fibers surrounded by a protective covering known as the epineurium. The arrangement of fascicles in nerves allows for the efficient transmission of nerve impulses throughout the body. Fascicles can vary in size and shape depending on the specific muscle or nerve they are a part of, but their organization and structure play a fundamental role in the functioning of the musculoskeletal and nervous systems.