Muscular System Overview

Flashcards covering essential vocabulary and definitions related to the Muscular System.

Muscle

Comprised of fascicles, which are groups of muscle fibers bound together.

Fascicles

Groups of muscle fibers bound together.

Myofibrils

Composed of sarcomeres, which are the structural units of muscle fibers.

Sarcomeres

Composed of actin and myosin, the contractile proteins.

Tendon

Connects muscle to bone.

Musculotendinous Junction

Where muscle meets tendon.

Tenoperiosteal Junction

Where tendon meets bone.

Agonist

The prime mover that performs a movement.

Antagonist

The muscle that performs the opposite movement of the agonist.

Co Contraction

The simultaneous contraction of agonist and antagonist muscles.

Synergist

A muscle that works in conjunction with another to perform the same action.

Active Insufficiency

Occurs when a multi-joint muscle cannot lengthen any further without damage.

Passive Insufficiency

Occurs when a multi-joint muscle cannot shorten any further due to length.

Tenodesis

Utilizes passive insufficiency to allow for opening and closing of the hand.

Concentric Contraction

Muscle shortens while contracting against gravity.

Eccentric Contraction

Muscle lengthens and decelerates against gravity.

Isometric Contraction

Muscle length stays the same during contraction.

Sliding Filament Theory

Describes the interaction between actin and myosin during muscle contraction.

Optimal Length

The length of a muscle at which it can generate maximum force.

Isokinetic Contractions

Speed of motion stays the same throughout contraction while resistance changes.

Open Chain

Distal segment is not fixed.

Closed Chain

Distal segment is fixed.