Video Lecture: Muscles of Mastication, Hyoid Muscles, Tongue, Pharynx, and Soft Palate – Vocabulary Flashcards

Vocabulary flashcards covering key terms, definitions, and functions from the video lecture on muscles of mastication, hyoid muscles, tongue, pharynx, and soft palate.

Origin

The fixed attachment site of a muscle, typically the proximal end; movement during contraction involves the insertion moving toward this point.

Insertion

The movable attachment site of a muscle; during contraction, this end moves toward the origin.

TMJ (Temporomandibular Joint)

The joint that connects the mandible to the skull, working with masticatory muscles to produce jaw movements.

Jaw Depression

Movement that lowers the mandible, resulting in mouth opening.

Jaw Elevation

Movement that raises the mandible, resulting in mouth closing.

Jaw Protrusion

Movement of the mandible forward (anteriorly).

Jaw Retraction

Movement of the mandible backward (posteriorly).

Lateral Deviation (Jaw)

Movement of the mandible side to side (toward the right or left).

Masseter

Elevates the mandible. Origin: zygomatic arch; Insertion: lateral surface of the angle and ramus of the mandible; Innervation: CN V3 (mandibular division).

Temporalis

Elevates the mandible; posterior fibers retract the mandible. Origin: temporal fossa; Insertion: coronoid process of the mandible; Innervation: CN V3.

Medial Pterygoid (Internal Pterygoid)

Elevates the mandible. Has superficial and deep heads; deep head origin: pterygoid fossa on the medial surface of the lateral pterygoid plate; superficial head origin: maxillary tuberosity and lateral pterygoid plate; Insertion: medial surface of the angle and ramus of the mandible; Innervation: CN V3.

Lateral Pterygoid (External Pterygoid)

Protrudes the mandible; inferior heads help depress/open the jaw; unilateral contraction causes deviation to the opposite side; superior head origin: infratemporal surface of greater wing of sphenoid; inferior head origin: lateral surface of the lateral pterygoid plate; Insertion: pterygoid fovea on the neck of the mandible and TMJ capsule; Innervation: CN V3.

Protrusion (Pterygoids)

Movement of the mandible forward due to bilateral contraction of lateral pterygoids.

Elevator Muscles of the Mandible

Masseter, temporalis, and medial (internal) pterygoid elevate the mandible to close the jaw.

Suprahyoid Muscles

Muscles located above the hyoid bone; collectively elevate the hyoid bone and larynx (e.g., during swallowing); anterior group can depress the mandible.

Infrahyoid Muscles

Muscles located below the hyoid bone; collectively depress the hyoid bone; innervation commonly via cervical nerves C1–C3 (ansa cervicalis).

Digastric Muscle (Anterior Belly)

Anterior belly: origin at the intermediate tendon; insertion at the digastric fossa of the mandible; Innervation: CN V3.

Digastric Muscle (Posterior Belly)

Posterior belly: origin at the mastoid notch; insertion at the intermediate tendon; Innervation: CN VII.

Mylohyoid

Forms the floor of the mouth; origin on the inner surface of the mandible along the mylohyoid line; insertion at the body of the hyoid; action elevates the tongue; Innervation: CN V3 (mylohyoid nerve).

Geniohyoid

Originates from the genial tubercle on the mandible; inserts on the body of the hyoid; action pulls the hyoid anterosuperiorly; Innervation: CN XII via C1.

Stylohyoid

Origin: styloid process; Insertion: body of the hyoid; action elevates/assists in retracting the hyoid; Innervation: CN VII.

Omohyoid

Has superior and inferior bellies; inferior originates from the scapula; superior inserts on the hyoid; action depresses the hyoid.

Sternohyoid

Origin: sternum; Insertion: hyoid; action depresses the hyoid; Innervation: cervical nerves C1–C3 via ansa cervicalis.

Sternothyroid

Origin: posterior surface of the sternum; Insertion: thyroid cartilage; action depresses the thyroid cartilage and larynx; Innervation: cervical nerves C1–C3.

Thyrohyoid

Origin: thyroid cartilage; Insertion: body and greater horn of the hyoid; action raises the thyroid cartilage and larynx; Innervation: cervical nerves C1 via ansa cervicalis.

Hyoid Bone

A U-shaped bone at the level of the C3 vertebrae; does not articulate with another bone; suspended by ligaments; supports tongue, swallowing, and speech.

Tongue – Intrinsic Muscles

Muscles located entirely within the tongue; innervated by CN XII; functions to change tongue shape; four pair: superior longitudinal, inferior longitudinal, transverse, vertical.

Superior Longitudinal

Intrinsic tongue muscle that runs from base to apex on the dorsal (top) surface; helps curl and shape the tongue; works with other intrinsic muscles to shorten and widen the tongue.

Inferior Longitudinal

Intrinsic tongue muscle on the ventral surface from base to apex; works with other intrinsic muscles to shape the tongue.

Transverse Tongue Muscle

Intrinsic tongue muscle that runs from the median septum to the lateral border; narrows and elongates the tongue.

Vertical Tongue Muscle

Intrinsic tongue muscle that runs from dorsal to ventral surface; flattens and broadens the tongue.

Genioglossus

Extrinsic tongue muscle; origin: mental spine (genial tubercles) of the mandible; insertion: tongue body; action protrudes the tongue; innervation: CN XII.

Styloglossus

Extrinsic tongue muscle; origin: styloid process; insertion: apex and lateral borders of the tongue; action retracts the tongue; Innervation: CN XII.

Hyoglossus

Extrinsic tongue muscle; origin: greater horn and body of the hyoid; insertion: lateral surface of the tongue; action depresses the tongue; Innervation: CN XII.

Palatoglossus

Soft palate muscle forming the anterior tonsillar pillar; origin: soft palate; insertion: sides of the tongue; action elevates the base of the tongue and helps close the oral cavity to the oropharynx; Innervation: pharyngeal plexus (CN X).

Palatopharyngeus

Soft palate muscle forming the posterior tonsillar pillar; origin: soft palate; insertion: walls of the laryngopharynx and thyroid cartilage; action moves palate posteriorly and the pharyngeal wall anteriorly; helps close nasopharynx during swallowing.

Levator Veli Palatini

Raises the soft palate to contact the posterior pharyngeal wall; origin: auditory tube area and temporal bone; insertion: median palatine raphe; action closes the nasopharynx during swallowing; Innervation: pharyngeal plexus (CN X).

Tensor Veli Palatini

Tenses the soft palate and opens the auditory tube; origin: auditory tube area and greater wing of the sphenoid; insertion: palatine aponeurosis; Innervation: nerve to medial pterygoid (branch of CN V3).

Uvula (Musculus Uvulae)

Muscle within the uvula of the soft palate; action shortens the uvula and shapes the posterior part of the soft palate to close off the nasal cavity during swallowing.

Soft Palate

The nonbony partition forming the roof of the oral cavity; elevates and seals against the posterior wall during swallowing and speaking; includes muscles like levator veli palatini, tensor veli palatini, palatoglossus, palatopharyngus, uvula.