Skeletal Muscle Anatomy

These flashcards cover key vocabulary and concepts related to skeletal muscle anatomy and function.

Skeletal muscle

An organ made up of different tissues, responsible for movement and force production.

Fascicles

Bundles of muscle fibers grouped together within a muscle.

Muscle fibers

The individual cells that make up the fascicles, also known as muscle cells.

Myofibrils

The structures within muscle fibers that contain sarcomeres.

Sarcomeres

The basic functional unit of muscle contraction, made up of myofilaments.

Myofilaments

The contractile proteins within a sarcomere, including actin and myosin.

Actin

The thin myofilament that plays a key role in muscle contraction.

Myosin

The thick myofilament that interacts with actin to produce muscle contraction.

Epimysium

The connective tissue sheath that surrounds an entire muscle.

Perimysium

The connective tissue that wraps around fascicles within a muscle.

Endomysium

The fine connective tissue that surrounds individual muscle fibers.

Tendon

Connective tissue that connects muscle to bone, can be direct or indirect.

Origination of muscles

Attachment of a muscle to an immovable or less movable bone.

Insertion of muscles

Attachment of a muscle to a movable bone.

Direct attachment

When the epimysium fuses to the periosteum of bone or perichondrium of cartilage.

Indirect attachment

When connective tissue wrappings extend beyond the muscle to form a tendon or aponeurosis.

Mitochondria

Organelles within muscle fibers that produce ATP for contractions.

Muscle spindle

Sensory receptors within muscles that detect changes in muscle length.

Extrafusal fiber

The regular muscle fibers responsible for muscle contraction.

Intrafusal fiber

The specialized fibers within muscle spindles that detect stretch.

Capillaries

Small blood vessels that supply muscles with oxygen and nutrients.

Neuromuscular junction

The synapse or junction between a motor neuron and a muscle fiber.

Chemical energy

Energy transformed by muscles from ATP into mechanical energy.

Sarcoplasm

The cytoplasm of a muscle cell.

Striated appearance

The banded look of skeletal and cardiac muscle cells due to the arrangement of myofilaments.

Connective tissue sheaths

Layers of tissue that cover muscles and muscle fibers, providing structure and support.