Muscle Structure and Attachments

These flashcards cover key vocabulary related to muscle structure and attachments as reviewed in the lecture.

Skeletal Muscles

Organs composed mainly of muscle tissue, along with connective tissue, blood vessels, and nerves.

Epimysium

Connective tissue layer that surrounds the entire muscle.

Perimysium

Connective tissue that divides muscle into compartments called fascicles.

Endomysium

Connective tissue that surrounds individual muscle fibers.

Fascicle

A bundle of muscle fibers.

Tendon

Connective tissue that attaches skeletal muscles to bones.

Aponeurosis

Sheet-like connective tissue that connects muscle to bone and provides strength and stability.

Fascicle Arrangement

The arrangement of muscle fibers that affects the force generated and the range of motion of the muscle.

Parallel Muscle Shape

Fascicles arranged in the same direction as the muscle's long axis, often flattened with broad attachments.

Circular Muscle Shape

Muscle fibers arranged concentrically, where relaxation increases the size of an opening, and contraction decreases it.

Convergent Muscle Shape

Fascicles that spread widely and converge at a single attachment point, such as a tendon.

Pennate Muscle Shape

Fascicles arranged at an angle to the tendon, producing more tension despite limited movement distance.

Tendon Sheaths

Connective tissue that protects some tendons, filled with synovial fluid for lubrication.

Collagen Fibers

Fibers found in connective tissue layers, providing strength and attachment to bones.

Ligaments

Connective tissue that binds bone to bone, holding structures together and keeping joints stable.

Inflammation of Tendon Sheaths

Can occur due to overuse, leading to swelling; the carpal tunnel is an example.

Bone Marrow

Soft tissue found within the cavities of bones, essential for blood cell production.

Muscle Fiber

An individual muscle cell, elongated and capable of contraction.

Sarcolemma

The cell membrane of a muscle fiber.

Sarcoplasm

The cytoplasm of a muscle fiber, containing myofibrils and other organelles.

Myofibril

Rod-like structures within a muscle fiber, composed of contractile proteins (actin and myosin).

Origin (of a muscle)

The fixed or less movable attachment point of a muscle.

Insertion (of a muscle)

The movable attachment point of a muscle, pulled towards the origin during contraction.

Functions of Skeletal Muscles

Produce movement, maintain posture, stabilize joints, generate heat, and guard body entrances/exits.