a&p midterm 2: Bones and Muscles

Mandible - structure

Unpaired facial bone forming the lower jaw. Contains the corpus (body), ramus, angle, coronoid process, condylar process, mylohyoid line, mental symphysis, and dental alveoli.

Mandible - function

Supports lower teeth; provides attachment for muscles of mastication; participates in speech, chewing, and swallowing.

Ramus

Vertical portion of the mandible extending superiorly from the angle.

Coronoid process

Anterior superior projection of the mandibular ramus; attachment site for the temporalis muscle.

Condylar Process

Posterior superior projection of the mandibular ramus that articulates with the temporal bone at the TMJ.

Mental Symphysis

Midline fusion point of the right and left halves of the mandible

Mylohyoid Line

Ridge on the inner mandible that serves as an attachment for the mylohyoid muscle.

Dental Alveoli (Alveolar Process)

Tooth sockets located in the alveolar process of the mandible.

Temporomandibular Joint - structure

Synovial joint formed by the mandibular condyle and temporal bone, separated by an articular disk and enclosed by a fibrous capsule.

Temporomandibular Joint - function

Allows opening, closing, protrusion, retraction, and side-to-side movement of the jaw.

Maxilla - structure

Bone of the upper jaw; contributes to the nose, palate, orbit, and facial skeleton.

Maxilla - function

Supports upper teeth and forms parts of the oral cavity, nasal cavity, and orbit.

Frontal process of maxilla

Superior projection of the maxilla that articulates with the frontal bone.

Infraorbital Margin

Lower border of the orbit formed partly by the maxilla.

Zygomatic Process of maxilla

Lateral extension of the maxilla that articulates with the zygomatic bone.

Nasal Crest

Ridge contributing to the nasal septum.

Palatine Process

Forms the anterior three-fourths of the hard palate.

Incisive Foramen

Opening in the anterior hard palate behind the incisors

Canine Fossa

Depression on the anterior maxilla; attachment area associated with facial muscles.

Intermaxillary Suture

Midline junction between the right and left maxillae.

Nasal Septum - function

Partition dividing the nasal cavity into right and left halves.

Nasal Septum - structure

Anterior cartilage, superior nasal bone, posterior-superior perpendicular plate of ethmoid, and posterior-inferior vomer.

Deviated Septum

Displacement of the nasal septum from the midline that may impair airflow.

Nasal Bones

Paired bones forming the bridge and superior anterior surface of the nose.

Vomer

Bone forming the inferior and posterior portions of the nasal septum.

Zygomatic Bone

Cheekbone that contributes to the orbit and provides attachment for upper lip elevators.

Zygomatic Arch

Formed by the temporal process of the zygomatic bone and the zygomatic process of the temporal bone.

Palatine Bone

Bone posterior to the maxilla contributing to the hard palate and posterior nasal cavity.

Horizontal Plate of Palatine Bone

Forms the posterior quarter of the hard palate.

Perpendicular Plate of Palatine Bone

Forms part of the posterior wall of the nasal cavity

Frontal bone

Unpaired cranial bone forming the forehead and roof of the orbits.

Coronal Suture

Junction between the frontal and parietal bones

Parietal Bones

Paired bones forming the superior and lateral portions of the cranium.

Sagittal Suture

Midline joint joining the left and right parietal bones.

Lambdoidal Suture

Junction between the parietal and occipital bones.

Occipital Bone

Unpaired bone forming the posterior and inferior skull.

Foramen Magnum

Large opening through which the medulla and spinal cord pass.

Occipital Condyles

Articular surfaces that connect the skull to the atlas vertebra.

Temporal Bone

Paired cranial bone containing structures for hearing and balance.

Mastoid Process

Projection of the temporal bone posterior to the ear.

Styloid Process

Slender projection serving as an attachment site for muscles and ligaments.

Petrous Portion

Dense region containing the cochlea and semicircular canals.

Internal Auditory Meatus

Passageway for cranial nerves associated with hearing and balance.

Ethmoid Bone

Unpaired bone forming part of the nasal cavity, septum, and orbit.

Crista Galli

Superior projection serving as an attachment for the dura mater.

Cribriform Plate

Sieve-like structure separating the nasal cavity from the brain.

Perpendicular Plate

Forms the superior portion of the nasal septum.

Superior and Middle Nasal Conchae

Curved projections that increase the surface area of the nasal cavity

Sphenoid Bone

Butterfly-shaped unpaired bone forming part of the cranial floor.

Greater Wings

Lateral extensions contributing to the skull and orbit.

Lesser Wings

Superior projections involved in formation of the orbit.

Pterygoid Plates

Processes providing attachment sites for muscles of mastication and the tensor veli palatini.

Sinuses

Air-filled cavities lined with respiratory mucosa that drain into the nasal cavity.

Maxillary Sinus

Largest paranasal sinus located in the maxilla.

Ethmoid Sinus

Honeycomb-like air cells medial to the orbit.

Sphenoid Sinus

Sinus located posterior to the ethmoid sinuses.

Sinuses - function

Warm and humidify air, provide immune protection, filter inhaled particles, enhance voice resonance, lighten skull weight, and cushion facial trauma.

Orbicularis Oris - function

Constricts oral opening, rounds lips, protrudes lips, presses lips against teeth.

Orbicularis Oris - attachments

Encircles the lips and attaches at the corners of the mouth.

Risorius - function

Retracts the corners of the mouth for smiling and grinning.

Risorius - attachments

Masseter fascia to corner of mouth and lower lip.

Buccinator - function

Flattens cheek, keeps food on molars, assists lip retraction.

Buccinator - attachments

Pterygomandibular ligament to orbicularis oris.

Levator Labii Superioris - function

Elevates the upper lip.

Zygomatic Major - function

Elevates and retracts the corners of the mouth.

Levator Anguli Oris - function

Draws mouth corners upward and medially.

Depressor Anguli Oris - function

Depresses corners of the mouth; contributes to frowning

Depressor Labii Inferiori - function

Pulls the lower lip downward.

Mentalis - function

Elevates chin tissue and curls the lower lip outward

Lingual Frenulum

Connects the inferior surface of the tongue to the mandible.

Fibrous Septum of Tongue

Midline partition running anterior to posterior within the tongue.

Genioglossus - function

Primary tongue protruder; can depress tongue body and retract the tip.

Genioglossus - attachments

Mental spines of mandible to tongue and hyoid.

Hyoglossus

Pulls the tongue down and backward.

Styloglossus - function

Pulls the tongue backward and upward.

Superior Longitudinal Muscle - function

Curls tongue upward; assists retraction and tip deviation.

inferior Longitudinal Muscle - function

Pulls tongue tip downward; assists retraction and deviation.

Transverse Tongue Muscle - function

Narrows and elongates the tongue.

Vertical Tongue Muscle - function

Flattens and widens the tongue.