Question

Bundles of muscle fibres are lined by
A. Mesomysium
B. Epimysium
C. Endomysium
D. Perimysium

Answer 1

Hint: Muscle fibres are organised into individual bundles within each skeletal muscle, each called a fascicle.

Complete Answer:
Each muscle is wrapped in a sheath called the epimysium of thick, irregular connective tissue, which enables a muscle to contract and move strongly while retaining its structural integrity. The epimysium also divides the muscle, allowing the muscle to move separately from other tissues and organs in the area.

Muscle fibres are arranged into individual bundles, each called a fascicle, within each skeletal muscle, by a middle layer of connective tissue called the perimysium. In the muscles of the limbs, this fascicular organisation is common; it enables the nervous system to activate a particular movement of a muscle by stimulating a subset of muscle fibres within a muscle bundle or fascicle.

Each muscle fibre is encased within each fascicle in a thin layer of collagen and reticular fibres called the endomysium connective tissue. The extracellular fluid and nutrients are included in the endomysium to sustain the muscle fibre. These nutrients are delivered to muscle tissue through blood.

Skeletal muscle cells (fibres) are elastic and delicate, as are other body cells. The connective tissue covering the fragile cells provides support and protection and allows them to withstand the forces of contraction. The coverings also provide openings for blood vessels and nerves to move through.

The Correct Answer is option (D) Perimysium.

Note: Epimysium, perimysium, and endomysium usually extend to form a thick ropelike tendon or a broad, flat, aponeurosis-like layer beyond the fleshy portion of the muscle, abdomen, or gastrointestinal tract. Tendon and aponeurosis form indirect muscle attachments to the periosteum of the bones or other muscle connective tissue. A muscle usually crosses a joint and is connected to the bones at both ends by tendons. One of the bones stays relatively constant or stable when, as a result of muscle contraction, the other end shifts.