Skeletal Muscle Interactions, Fascicle Arrangement, Naming, and Axial Musculature

Vocabulary flashcards covering skeletal muscle terminology, interactions, fascicle patterns, naming criteria, and axial musculature of the head, neck, and back.

Insertion

The moveable end of a muscle that attaches to the bone being pulled during contraction.

Origin

The end of a muscle attached to a fixed or stabilized bone.

Prime Mover (Agonist)

The principal muscle directly involved in producing a specific action.

Synergist

A muscle that assists the prime mover in performing a specific action.

Fixator

A synergist that stabilizes the bone serving as the attachment site for the prime mover's origin.

Antagonist

A muscle with an action opposite to that of the prime mover; it maintains body or limb position and controls rapid movements.

Belly

The central, large mass of muscle tissue located between the origin and insertion.

Fusiform Muscle

A parallel muscle with a spindle-shaped central belly that tapers as it extends toward its origin and insertion.

Circular Muscle (Sphincter)

A muscle with concentrically arranged fascicles that contracts to close or shrink an opening and relaxes to expand it.

Convergent Muscle

A muscle with widespread fascicles over a broad area that converge onto a single attachment point such as a tendon, aponeurosis, or raphe.

Pennate Muscle

A muscle whose fascicles blend into a tendon running through the central region for its full length, allowing high force production but limited pull distance.

Unipennate Muscle

A pennate muscle where fascicles are located on only one side of the central tendon.

Bipennate Muscle

A pennate muscle that has fascicles arranged on both sides of the central tendon.

Multipennate Muscle

A pennate muscle in which fascicles wrap around a tendon or branch into multiple tendons, allowing selective stimulation to alter direction of pull.

Etymology

The study of how word roots entered a language and how their meanings evolved over time.

Epicranial Aponeurosis

A broad, helmet-like tendon (also called galea aponeurosis) connecting the frontal belly and occipital belly of the occipitofrontalis muscle across the cranium.

Buccinator

A principal muscle of the cheek that compresses the cheek to allow whistling, blowing, sucking, and assist in chewing.

Corrugator Supercilii

A small facial muscle located at the bridge of the nose that acts as the prime mover of the eyebrows.

Extrinsic Eye Muscles

A group of six muscles originating outside the eye on the skull and inserting on the eyeball surface to produce coordinated eye movements.

Mastication

The anatomical term for chewing, carried out by muscles that exert pressure to bite and break down food.

Masseter

The main muscle of mastication that elevates the mandible to close the mouth.

Temporalis

A muscle located on the temple that elevates and retracts the mandible to assist in chewing.

Extrinsic Tongue Muscles

Muscles originating outside the tongue (containing the root glossus) that move the tongue in various directions.

Intrinsic Tongue Muscles

Muscles with origins and insertions entirely inside the tongue that change its shape, such as curling or flattening it.

Endotracheal Intubation

A procedure performed during general anesthesia where a tube is inserted into the trachea to keep the airway open and clear of relaxed tongue muscles.

Suprahyoid Muscles

A set of muscles superior to the hyoid bone (digastric, stylohyoid, mylohyoid, geniohyoid) that elevate the hyoid bone, larynx, and mouth floor during swallowing.

Infrahyoid Muscles

A group of strap-like muscles inferior to the hyoid bone (omohyoid, sternohyoid, thyrohyoid, sternothyroid) that depress the hyoid bone and control larynx position.

Sternocleidomastoid

A major neck muscle originating on the sternum and clavicle and inserting on the mastoid process that divides the neck into triangles and flexes or rotates the head.

Erector Spinae Group

The principal muscle mass of the back and primary extensor of the vertebral column, consisting of the iliocostalis, longissimus, and spinalis groups.

Scalene Muscles

Anterior, middle, and posterior muscles in the neck that flex, laterally flex, and rotate the head, while also assisting in deep inhalation.