Articulation L1 - Intro Cavities of the Vocal Tract_The Skull Moodle.pptx

Articulation Articulation - Introduction • Respiratory system - Power source • Phonation - Laryngeal, vibrating elements (vocal tone) • Articulation: adjustments of the shape and the acoustical properties of the vocal tract • Articulators: the structures that mediate these adjustments • Consonants...

Articulation Articulation - Introduction • Respiratory system - Power source • Phonation - Laryngeal, vibrating elements (vocal tone) • Articulation: adjustments of the shape and the acoustical properties of the vocal tract • Articulators: the structures that mediate these adjustments • Consonants, Vowels (Formants) – Voiced vs. Unvoiced • Supportive framework and muscular system Cavities of the Vocal Tract • • • • Pharyngeal Oral Buccal* Nasal • Resembles the letter F Pharyngeal Cavity - Pharynx is a musculomembranous tube extending from the base of the skull to the cricoid cartilage (posterior to the larynx) - The pharyngeal tube is largely connective tissue and mucoperiosteum superiorly, becomes increasingly muscular as it continues downward toward the esophagus - Cavity of the pharynx is often divided into the nasopharynx, oropharynx, and laryngopharynx - In all, the pharynx communicates with the tympanic, oral, laryngeal, and nasal cavities as well as the esophagus Oral Cavity • Bounded anteriorly and laterally by the lips and teeth, superiorly by the hard and soft palates, posteriorly by the palatoglossal arches, and inferiorly by the muscular floor consisting primarily of the tongue. • Contains key articulators: the lips, teeth, alveolar ridge, hard palate, velum (soft palate), tongue, and mandible. Nasal Cavities Two narrow, approximately symmetrical chambers separated by the nasal septum Communicate with the exterior by way of the nostrils and with the nasopharynx by way of the choanae (posterior nares) Lateral walls also contain orifices through which the nasal cavities communicate with the paranasal sinuses Structures of the Vocal Tract • Lips, teeth, alveolar ridge, hard palate, velum (soft palate), tongue, mandible, oral cavity, nasal cavity, and pharyngeal cavity. The Skull • Bony framework of the head • Composed of 28 irregular bones held together by joints known as sutures (except for mandible) • Sutures: immovable (fibrous) joints found only in the skull. Five prominent sutures include the coronal, sagittal, squamous, lamboidal, and occipitomastoid. The Skull • Skull in divided into the cranium and the facial skeleton – Cranium: “brain case” houses and protects the brain – Facial skeleton: forms the framework for organs of mastication, speech production, respiration, special senses, and muscles for facial expression Bones of the Skull Bones of the Cranium • Ethmoid (unpaired) • Sphenoid (unpaired) • Frontal (unpaired) • Occipital (unpaired)* • Parietal (paired) • Temporal (paired)* * We will consider these “major” bones for the exam. Bones of the Facial Skeleton • Mandible (unpaired)* • Vomer (unpaired) • Maxillary (paired)* • Nasal (paired) • Palatine (paired)* • Lacrimal (paired) • Zygomatic (paired)* • Inferior Nasal Concha (paired) Skull bones (anterior) Skull bones (lateral) Gross Anatomy & Major Landmarks Orbits Orbit - 2 most obvious holes/depressions in the anterior of skull - Each orbit is a depression that in life contains an eye and associated structures - Comprised of parts of several different bones Nasal Cavities and Conchae (Turbinates) Nasal conchae or turbinates create greater surface area to aid in cleansing and humidifying air that passes through the nostrils into the lungs The Articulated Skull Temporae (temples): indented, lateral sides of skull Vertex: most superior point of skull Frons: forehead Occiput: most posterior point of skull Calvaria: bowl that comprises the skull cap External Auditory Meatus: ear canal Mastoid process: rounded protuberance immediately behind and below the EAM Styloid Process: sharp bony projection on medial to EAM on inferior surface of skull Foramen Magnum: opening found at base of skull between and behind the styloid processes The Maxillae – Facial Bones • Paired bones that form the entire upper jaw and contribute to the formation of the roof of the mouth, the floor and lateral walls of the nasal cavity, and the floor of the orbital cavity • Play an important role in speech production • Each maxillary bone articulates with 9 bones The Maxillae – Landmarks • Fused at midline, just below nasal cavity, via the intermaxillary suture (continued to central incisor in front and palatine process in back) • Incisive foramen – small opening just posterior to upper central incisor • Premaxilla – triangular region formed by sutures that extend from incisive foramen to between lateral incisors and canine teeth Maxillary Corpus and Processes Each maxilla has a corpus & 5 processes Processes contribute to the strength of the facial skeleton Zygomatic process: triangular; directed laterally; articulates with the zygomatic bone Frontal process: very strong bony plate, articulates with frontal bone of cranium; forms the lateral bony framework of the nose; its medial surface contributes to the lateral wall of the nasal cavity Orbital process: creates much of the inferior orbit of the eye Alveolar process: thick, spongy part of the maxilla that houses the teeth; divided into 8 cavities each of which contains a tooth; forms the alveolar arch or ridge Maxillary Processes Palatine process: paired, thick, horizontal, medially directed projection forms most of the floor of the nasal cavity and the anterior ¾ of the bony roof of the mouth (hard palate) considerably thicker in front than in back; on the nasal side of each process is a small ridge called the nasal crest; nasal crest is continued forward as a sharp projection called the anterior nasal spine Maxillary Paranasal Sinuses • Maxillae are not the massive bones their size might indicate • Not solid masses, but rather contain an extensive sinus • These sinuses are present at birth Craniofacial Development Face Development in the Womb - Inside the Human Body: Creation - BBC One http://www.youtube.com/watch?v=wFY_KPFS3LA Incomplete Formation: Cleft lip/palate https://www.youtube.com/watch?v=MtgHro9iCQ4 The Mandible – Facial Bone • Regarded as a single bone (mirrored halves are joined by a fibrous symphysis at birth that ossifies during 1st year) • Large, dense, extremely strong • U-shaped The Mandible • Body/Corpus: portion that makes up arch • Mental symphysis: point where the two halves are joined; when viewed from front appears as a vertically directed midline ridge • Mental symphysis bifurcates near the lower border to form the mental protuberance (point of the chin); it’s usually depressed in the center which gives rise to two anterior projections call mental tubercles The Mandible Alveolar arch: the upper surface of a toothbearing mandible; contains a dental alveolus (tooth socket) for each tooth Mandibular Rami: quadrilateral and perpendicularly directed plates extending upward from the posterior portion of the body of the mandible Angle of the mandible: formed at the juncture of the posterior border of a ramus and the inferior border of the corpus (~90 degrees in adults) Mandibular foramen: an identifiable landmark on the medial surface of the ramus; permits entrance of nerves and blood vessels The Mandible • Mental foramen – small openings in the chin or mentum just lateral and superior to each mental tubercle • Mylohyoid line: on the medial surface of the body of the mandible; marks the site of the mandibular attachment of the mylohyoid muscle The Mandible Superior border of each ramus contains a coronoid and a condylar process; these processes are separated by the mandibular notch Coronoid process: anterior to the condylar process; a beak-like projection directed somewhat posteriorly; serves as point of attachment for the temporalis muscle Condylar process: composed of a head and neck; the head articulates with cranium at the temporal bone on each side in the only freely moveable joints of the skull (temporomandibular joint) Pterygoid fovea: located on the condylar process; a depression for the attachment of the lateral pterygoid muscle Pterygoid fovea Articulatory Function of the Mandible • Major contribution to speech: houses the lower teeth and forms the points of attachment for much of the tongue and other musculature • Movements of the mandible and its contained tongue result in modifications of the size and acoustical characteristics of the oral cavity • Extent of jaw movement during normal speech production is surprisingly small; the jaw need not move at all during speech production Nasal Bones – Facial Bones • Paired • Form bridge of nose • Lie medially to frontal process of maxillary bones Palatine Bones – Facial Bones - Relatively small, at the back of the hard palate/nasal cavity; articulate with 6 bones - Contribute to the formation of 3 cavities: the floor and lateral wall of the nasal cavity, the posterior ¼ of the roof of the mouth, and the floor of the orbital cavity - Anterior is serrated for strong articulation with palatine processes of the maxillae; posterior border is point of attachment for the velum - Posteriorly, pair of palatine bones meets in the midline and extends to form the posterior nasal spine Lacrimal Bones – Facial Bones Zygomatic Bones – Facial Bones - Contributes to the lateral wall and floor of the orbital cavity - Some muscles of articulation and mastication attach to the zygomatic bone - Consists of a body (~ quadrilateral in shape) & four processes (orbital, frontosphenoidal, maxillary, and temporal) - Maxillary process: articulates with zygomatic process of maxillary bone - Temporal process: articulates with zygomatic process of temporal bone - These articulations form the zygomatic arch a.k.a. the cheekbone Inferior Nasal Conchae – Facial Bones While the superior and middle nasal conchae form part of the perpendicular plate of the ethmoid bone, the inferior nasal concha is a bony structure by itself. It sits on the vertical bony nasal septum, that separates the left and right sides of the nasal cavity. Vomer Bone – Facial Bone The vomer is the posterior part of the nasal septum which creates the division between the left and right sides of the nasal cavity. The Cranium • Aka the brain case • Comprised of 8 bones Frontal Bone - Cranium Sinuses of Frontal Bone – Frontal Paranasal Sinuses Virtually absent at birth, begin to develop during the 1st or 2nd year, reach maturity at puberty Parietal Bones - Cranium Occipital Bone - Cranium - Unpaired, trapezoidal in shape - Forms the lower and back portions of the cranium - Foramen magnum: a large opening; marks the junction of the spinal cord and brain - Portions of the bone lateral to the foramen magnum contain (on their undersurfaces) occipital condyles for articulation with the superior facets of the first cervical vertebra Temporal Bones - Cranium - Paired; form most of lateral base and sides of the braincase - Consists of five parts: squamous, petrous, mastoid, tympanic, styloid - Zygomatic process of squamous portion articulates with temporal process of zygomatic bone (cheekbone) - Contain essential organs of hearing - Temporomandibular Joint (TMJ) - Each temporal bone is joined at the mandibular fossa (depression between styloid and zygomatic processes) to the mandible by a freely movable joint – the TMJ Ethmoid Bone - Cranium Anterior view Superior view Ethmoid bone is at the roof of the nasal cavity, and between the two orbital cavities. Part of the anterior cranial fossa, where it separates the nasal cavity (inferiorly) from the cranial cavity (superiorly). Ethmoid Paranasal Sinuses Present at birth. Sphenoid Bone - Cranium anterior view The sphenoid bone is situated in the middle of the skull towards the front, in front of the temporal bone and the basal part of the occipital bone. It is the only bone that connects to all other bones of the cranium. posterior view Sphenoid Paranasal Sinus Not present at birth; form in 3rd year of life. The Sinuses • Sinuses are air-filled spaces • Lined with mucoperiosteum, a thin membrane formed by the fusion of periosteum and mucous membrane • All four pairs of paranasal sinuses drain into the nasal cavities Functions of the Sinuses • No real significance with respect to speech production, except perhaps for minimal contributions to the resonant characteristics of the skull bone Color-coded rotating skull with exploded view https://www.youtube.com/watch?v=FrpVzSK23Q0