Generating Movement in the Body - Musculoskeletal and Muscular Function

A complete set of vocabulary flashcards covering musculoskeletal connective tissues, joint classifications, motor unit recruitment, muscle contractions, sliding filament theory, and muscle roles.

Connective Tissues

Tissues including bone, ligaments, cartilage, fascia, and tendons that function to increase stability and permit movement.

Articulations

Joints categorized into three main structural and functional types: fibrous, cartilaginous, and synovial.

Classes of Synovial Joints

Classes of synovial joints that vary in stability and movement, including ball and socket, gliding, pivot, saddle, hinge, and condyloid/ellipsoid.

Motor Unit

A functional grouping of muscle fibers that contracts using the all-or-none principle.

All-or-None Principle

The principle stating that all muscle fibers within a motor unit contract fully or not at all upon stimulation.

Acetylcholine

A neurotransmitter that stimulates skeletal muscle contraction.

Motor Unit Fiber Types

Motor units differentiated by fiber type and neuron diameter, categorized into type I, type IIa, and type IIx.

Principle of Orderly Recruitment

The pattern where muscle contraction involves progressive recruitment of motor units from type I to IIa to IIx as activity intensity increases.

Types of Muscular Contractions

The four ways muscular contractions can be described: isometric, isotonic concentric, isotonic eccentric, and isokinetic.

Reciprocal Inhibition

The mechanism by which muscle pairings (agonist and antagonist) function together, allowing one muscle to contract while the opposing muscle relaxes.

Sliding Filament Theory

The theory describing the interaction between myofilaments and molecules (calcium, ATP, actin, myosin, troponin, and tropomyosin) responsible for sarcomere or muscle contraction.

Muscle Origin

The attachment point of a muscle (such as the biceps brachii attachment to the scapula) that remains stable and still during muscle contraction.

Muscle Insertion

The attachment point of a muscle on a distal bone (such as the biceps brachii attachment to the radius) that moves and is affected most by contraction.

Agonist (Prime Mover)

The primary muscle responsible for causing a specific movement, such as the biceps brachii during a biceps curl.

Antagonist

The muscle that opposes the action of the prime mover, such as the triceps brachii during a biceps curl.

Synergist

Helper muscles that assist the prime mover during a movement, such as the brachialis during a biceps curl.

Fixator

Stabilizer muscles that hold a bone firmly in place, such as the rhomboideus holding the scapula firmly in place during a biceps curl.

Sarcomere and Muscle Fibre Structure

Anatomical structures of a muscle fibre (sarcolemma, nucleus, mitochondrion, myofibril, sarcoplasmic reticulum) and a relaxed sarcomere (Z disc, actin thin filament, myosin thick filament, tropomyosin, M line, H zone, A band, I band).

Myofiber Hypertrophy vs. Hyperplasia Diagram

Comparison illustrating myofiber hypertrophy (muscle gets bigger due to more proteins without gaining muscle cells) versus myofiber splitting or hyperplasia.

Muscle Actions During a Biceps Curl Diagram

Diagram depicting the biceps brachii origin points on the scapula and insertion on the radius, alongside muscle roles: prime mover (biceps brachii), synergist (brachialis), antagonist (triceps brachii), and fixator (rhomboideus).