© 2016 Pearson Education, Inc.

The Skeleton The skeletal system is composed of bones, cartilages, joints, ligaments Mostly bone Cartilage occurs in isolated areas Ligaments connect bones and reinforce joints © 2016 Pearson Education, Inc.

The Skeleton The skeleton accounts for 20% of body mass Two major divisions Axial skeleton Appendicular skeleton © 2016 Pearson Education, Inc.

Part 1: The Axial Skeleton Axial skeleton consists of 80 bones divided into three major regions: Skull Vertebral column Thoracic cage © 2016 Pearson Education, Inc.

Part 1: The Axial Skeleton Axial skeleton has three functions: Form longitudinal axis of body Support head, neck, and trunk Protect brain, spinal cord, and thoracic organs © 2016 Pearson Education, Inc.

Figure 7.1a The human skeleton. Cranium Skull Facial bones Clavicle Thoracic cage Scapula (ribs, sternum and thoracic vertebrae) Sternum Rib Humerus Vertebra Vertebral column Radius Ulna Sacrum Carpals Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges Anterior view © 2016 Pearson Education, Inc.

Figure 7.1b The human skeleton. Cranium Bones of pectoral girdle Clavicle Scapula Upper limb Rib Humerus Vertebra Radius Ulna Bones of pelvic girdle Carpals Phalanges Metacarpals Femur Lower limb Tibia Fibula Posterior view © 2016 Pearson Education, Inc.

7.1 The Skull Skull is most complex bony structure in body Most skull bones are flat and firmly locked together (except for mandible) Joints are called sutures Have a serrated, saw-tooth appearance © 2016 Pearson Education, Inc.

7.1 The Skull Formed by two sets of bones: Cranial bones (cranium) Enclose the brain in the cranial cavity Provide sites of attachment for head and neck muscles © 2016 Pearson Education, Inc.

7.1 The Skull Facial bones Contain cavities for special sense organs for sight, taste, and smell Provide openings for air and food passage Secure teeth Anchor facial muscles used for facial expression © 2016 Pearson Education, Inc.

Cranial and facial divisions of the skull Figure 7.2a The skull. Bones of cranium Coronal suture Squamous suture Lambdoid suture Facial bones Cranial and facial divisions of the skull © 2016 Pearson Education, Inc.

Overview of Skull Geography Cranium is divided into a vault and a base Cranial vault forms superior, lateral, and posterior portion of skull Cranial base forms inferior aspect of skull Internally base is divided into three fossae: anterior, middle, posterior fossae Area referred to as cranial cavity © 2016 Pearson Education, Inc.

Superior view of the cranial fossae Figure 7.2b The skull. Anterior cranial fossa Middle cranial fossa Posterior cranial fossa Superior view of the cranial fossae © 2016 Pearson Education, Inc.

Lateral view of cranial fossae showing the contained brain regions Figure 7.2c The skull. Temporal lobe of cerebrum Frontal lobe of cerebrum Cerebellum Posterior Cranial fossae Middle Anterior Lateral view of cranial fossae showing the contained brain regions © 2016 Pearson Education, Inc.

Overview of Skull Geography (cont.) Skull has 85 named openings Foramina, canals, fissures Provide passageways for spinal cord, major blood vessels, and cranial nerves © 2016 Pearson Education, Inc.

Cranium Cranium is comprised of eight cranial bones: Frontal bone Parietal bones (two—left and right) Occipital bone Temporal bones (two—left and right) Sphenoid bone Ethmoid bone © 2016 Pearson Education, Inc.

Cranium (cont.) Frontal bone: shell-shaped bone forms anterior portion of cranium Vertical part is the forehead Supraorbital foramen (notch) allows supraorbital artery and nerve to pass to forehead © 2016 Pearson Education, Inc.

Figure 7.4a Anterior and posterior views of the skull. Parietal bone Frontal bone Squamous part of frontal bone Glabella Frontonasal suture Nasal bone Supraorbital foramen (notch) Sphenoid bone (greater wing) Supraorbital margin Superior orbital fissure Temporal bone Optic canal Ethmoid bone Inferior orbital fissure Lacrimal bone Zygomatic bone Middle nasal concha Infraorbital foramen Ethmoid bone Perpendicular plate Maxilla Inferior nasal concha Vomer Mandible Mental foramen Mandibular symphysis Anterior view © 2016 Pearson Education, Inc.

Figure 7.7a The base of the cranial cavity. View Cribriform plate Ethmoid bone Crista galli Frontal bone Anterior cranial fossa Cribriform foramina Sphenoid Lesser wing Optic canal Greater wing Foramen rotundum Hypophyseal fossa of sella turcica Foramen ovale Foramen spinosum Middle cranial fossa Foramen lacerum Temporal bone (petrous part) Internal acoustic meatus Posterior cranial fossa Jugular foramen Parietal bone Hypoglossal canal Occipital bone Foramen magnum Superior view of the skull © 2016 Pearson Education, Inc.

Figure 7.7b The base of the cranial cavity. View Crista galli Frontal bone Ethmoid bone Cribriform plate Cribriform foramina Anterior cranial fossa Optic canal Lesser wing Sphenoid Greater wing Foramen rotundum Hypophyseal fossa of sella turcica Foramen ovale Foramen spinosum Middle cranial fossa Foramen lacerum Temporal bone (petrous part) Posterior cranial fossa Jugular foramen Parietal bone Occipital bone Foramen magnum Photo of superior view of the skull, calvaria removed © 2016 Pearson Education, Inc.

Cranium (cont.) Parietal bones and the major sutures Two large parietal bones form most of superior and lateral aspects of cranial vault © 2016 Pearson Education, Inc.

Cranium (cont.) Four sutures mark articulations of parietal bones with frontal, occipital, and temporal bones: Coronal suture: between parietal bones and frontal bone Sagittal suture: between right and left parietal bones Lambdoid suture: between parietal bones and occipital bone Squamous (squamosal) sutures: between parietal and temporal bones on each side of skull © 2016 Pearson Education, Inc.

Cranial and facial divisions of the skull Figure 7.2a The skull. Bones of cranium Coronal suture Squamous suture Lambdoid suture Facial bones Cranial and facial divisions of the skull © 2016 Pearson Education, Inc.

Figure 7.4b Anterior and posterior views of the skull. Sagittal suture Parietal bone Sutural bone Lambdoid suture Inferior nuchal line Occipital bone Superior nuchal line External occipital protuberance Mastoid process of temporal bone Occipitomastoid suture Occipital condyle External occipital crest Posterior view © 2016 Pearson Education, Inc.

Occipitomastoid suture Maxilla Figure 7.5a Bones of the lateral aspect of the skull, external and internal views. Coronal suture Frontal bone Sphenoid bone (greater wing) Parietal bone Ethmoid bone Squamous suture Lacrimal bone Lambdoid suture Lacrimal fossa Occipital bone Nasal bone Temporal bone Zygomatic process Zygomatic bone Occipitomastoid suture Maxilla External acoustic meatus Mastoid process Alveolar processes Styloid process Condylar process Mandible Mandibular notch Mental foramen Mandibular ramus External anatomy of the right side of the skull Coronoid process Mandibular angle © 2016 Pearson Education, Inc.

Photograph of right side of skull Figure 7.5b Bones of the lateral aspect of the skull, external and internal views. Frontal bone Coronal suture Sphenoid bone (greater wing) Parietal bone Squamous suture Ethmoid bone Lacrimal bone Temporal bone Nasal bone Zygomatic process Lambdoid suture Lacrimal fossa Occipital bone Zygomatic bone Occipitomastoid suture Coronoid process Maxilla External acoustic meatus Alveolar processes Mastoid process Styloid process Mandible Mental foramen Condylar process Mandibular notch Mandibular angle Mandibular ramus Photograph of right side of skull © 2016 Pearson Education, Inc.

(perpendicular plate) Figure 7.5c Bones of the lateral aspect of the skull, external and internal views. Parietal bone Squamous suture Coronal suture Temporal bone Frontal bone Greater wing Lambdoid suture Sphenoid bone Lesser wing Occipital bone Frontal sinus Crista galli Nasal bone Sphenoidal sinus Occipitomastoid suture Ethmoid bone (perpendicular plate) External occipital protuberance Vomer Incisive canal Internal acoustic meatus Maxilla Pterygoid process of sphenoid bone Alveolar processes Sella turcica of sphenoid bone Mandible Mandibular foramen Palatine bone Palatine process of maxilla Midsagittal section showing the internal anatomy of the left half of skull © 2016 Pearson Education, Inc.

(perpendicular plate) Figure 7.5d Bones of the lateral aspect of the skull, external and internal views. Greater wing of sphenoid bone Lesser wing of sphenoid bone Frontal sinus Crista galli Petrous part of temporal bone Ethmoid bone (perpendicular plate) External occipital protuberance Palatine bone Internal acoustic meatus Sella turcica and sphenoidal sinus Photo of skull cut through the midline, same view as in (c) © 2016 Pearson Education, Inc.

Cranium (cont.) Occipital bone Forms most of skull’s posterior wall and posterior cranial fossa Foramen magnum: “large hole” through which brain connects with spinal cord Flanked by pair of occipital condyles that articulate with 1st vertebra © 2016 Pearson Education, Inc.

Cranium (cont.) External occipital protuberance: protrusion just superior to foramen magnum © 2016 Pearson Education, Inc.

Figure 7.4b Anterior and posterior views of the skull. Sagittal suture Parietal bone Sutural bone Lambdoid suture Inferior nuchal line Occipital bone Superior nuchal line External occipital protuberance Mastoid process of temporal bone Occipitomastoid suture Occipital condyle External occipital crest Posterior view © 2016 Pearson Education, Inc.

Figure 7.6a Inferior aspect of the skull, mandible removed. Maxilla (palatine process) Incisive fossa Intermaxillary suture Hard palate Median palatine suture Palatine bone (horizontal plate) Infraorbital foramen Maxilla Zygomatic bone Sphenoid bone (greater wing) Temporal bone (zygomatic process) Foramen ovale Vomer Foramen spinosum Foramen lacerum Mandibular fossa Carotid canal External acoustic meatus Styloid process Stylomastoid foramen Mastoid process Jugular foramen Temporal bone (petrous part) Occipital condyle Basilar part of the occipital bone Inferior nuchal line Parietal bone Superior nuchal line External occipital crest Occipital bone External occipital protuberance Foramen magnum Inferior view of the skull (mandible removed) © 2016 Pearson Education, Inc.

Figure 7.6b Inferior aspect of the skull, mandible removed. Hard palate Zygomatic arch Foramen ovale Foramen lacerum Mandibular fossa Foramen spinosum Carotid canal Styloid process Mastoid process Jugular foramen Occipital condyle Foramen magnum Superior nuchal line Photo of inferior view of the skull © 2016 Pearson Education, Inc.

Cranium (cont.) Temporal bones: paired bones that make up inferolateral aspects of skull and parts of cranial base zygomatic processes articulate with zygomatic bone to form zygomatic arch and mandibular fossa makes up part of temporomandibular joint external acoustic meatus (external ear canal) © 2016 Pearson Education, Inc.

Cranium (cont.) middle and internal ear cavities Makes up part of the middle cranial fossa Several foramina penetrate petrous region: Jugular foramen allows passage of three cranial nerves Carotid canal: passageway for internal carotid artery Internal acoustic meatus cranial nerve passageways Mastoid and styloid processes: areas for attachment of several neck and tongue muscles © 2016 Pearson Education, Inc.

Occipitomastoid suture Maxilla Figure 7.5a Bones of the lateral aspect of the skull, external and internal views. Coronal suture Frontal bone Sphenoid bone (greater wing) Parietal bone Ethmoid bone Squamous suture Lacrimal bone Lambdoid suture Lacrimal fossa Occipital bone Nasal bone Temporal bone Zygomatic process Zygomatic bone Occipitomastoid suture Maxilla External acoustic meatus Mastoid process Alveolar processes Styloid process Condylar process Mandible Mandibular notch Mental foramen Mandibular ramus External anatomy of the right side of the skull Coronoid process Mandibular angle © 2016 Pearson Education, Inc.

Photograph of right side of skull Figure 7.5b Bones of the lateral aspect of the skull, external and internal views. Frontal bone Coronal suture Sphenoid bone (greater wing) Parietal bone Squamous suture Ethmoid bone Lacrimal bone Temporal bone Nasal bone Zygomatic process Lambdoid suture Lacrimal fossa Occipital bone Zygomatic bone Occipitomastoid suture Coronoid process Maxilla External acoustic meatus Alveolar processes Mastoid process Styloid process Mandible Mental foramen Condylar process Mandibular notch Mandibular angle Mandibular ramus Photograph of right side of skull © 2016 Pearson Education, Inc.

Figure 7.8 The temporal bone. External acoustic meatus Squamous part Zygomatic process Petrous part Mastoid process Mandibular fossa Styloid process Tympanic part © 2016 Pearson Education, Inc.

Figure 7.6a Inferior aspect of the skull, mandible removed. Maxilla (palatine process) Incisive fossa Intermaxillary suture Hard palate Median palatine suture Palatine bone (horizontal plate) Infraorbital foramen Maxilla Zygomatic bone Sphenoid bone (greater wing) Temporal bone (zygomatic process) Foramen ovale Vomer Foramen spinosum Foramen lacerum Mandibular fossa Carotid canal External acoustic meatus Styloid process Stylomastoid foramen Mastoid process Jugular foramen Temporal bone (petrous part) Occipital condyle Basilar part of the occipital bone Inferior nuchal line Parietal bone Superior nuchal line External occipital crest Occipital bone External occipital protuberance Foramen magnum Inferior view of the skull (mandible removed) © 2016 Pearson Education, Inc.

Figure 7.7a The base of the cranial cavity. View Cribriform plate Ethmoid bone Crista galli Frontal bone Anterior cranial fossa Cribriform foramina Sphenoid Lesser wing Optic canal Greater wing Foramen rotundum Hypophyseal fossa of sella turcica Foramen ovale Foramen spinosum Middle cranial fossa Foramen lacerum Temporal bone (petrous part) Internal acoustic meatus Posterior cranial fossa Jugular foramen Parietal bone Hypoglossal canal Occipital bone Foramen magnum Superior view of the skull, calvaria removed © 2016 Pearson Education, Inc.

Cranium (cont.) Sphenoid bone: complex, bat-shaped bone Keystone bone that articulates with all other cranial bones Body also includes sella turcica prominence that includes hypophyseal fossa area enclosing the pituitary gland © 2016 Pearson Education, Inc.

Cranium (cont.) Sphenoid contains three pairs of processes: Greater wings Lesser wings Pterygoid processes © 2016 Pearson Education, Inc.

Cranium (cont.) Sphenoid contains several foramina: Optic canals: allow passage of optic nerves Foramen rotundum and foramen ovale: also passageways for cranial nerves Foramen spinosum: opening for arteries © 2016 Pearson Education, Inc.

Figure 7.9 The sphenoid bone. Optic canal Lesser wing Superior orbital fissure Greater wing Foramen rotundum Hypophyseal fossa of sella turcica Foramen ovale Foramen spinosum Body of sphenoid Superior view Body of sphenoid Lesser wing Greater wing Superior orbital fissure Pterygoid process Posterior view © 2016 Pearson Education, Inc.

Cranium (cont.) Ethmoid bone: deepest skull bone Superior part formed by paired cribriform plates that also form roof of nasal cavity and floor of anterior cranial fossa © 2016 Pearson Education, Inc.

Cranium (cont.) Ethmoid bone Crista galli: triangular process that is point of attachment for brain’s dura mater covering Perpendicular plate: forms superior part of nasal septum and is flanked by lateral masses that contain sinuses called ethmoidal air cells Lateral masses extend medially to form superior and middle nasal conchae Orbital plates contribute to medial wall of orbits © 2016 Pearson Education, Inc.

Figure 7.10 The ethmoid bone. Crista galli Cribriform plate with cribriform foramina Orbital plate Left lateral mass Ethmoidal air cells Perpendicular plate Middle nasal concha © 2016 Pearson Education, Inc.

Figure 7.4a Anterior and posterior views of the skull. Parietal bone Frontal bone Squamous part of frontal bone Glabella Frontonasal suture Nasal bone Supraorbital foramen (notch) Sphenoid bone (greater wing) Supraorbital margin Superior orbital fissure Temporal bone Optic canal Ethmoid bone Inferior orbital fissure Lacrimal bone Zygomatic bone Middle nasal concha Infraorbital foramen Ethmoid bone Perpendicular plate Maxilla Inferior nasal concha Vomer Mandible Mental foramen Mandibular symphysis Anterior view © 2016 Pearson Education, Inc.

Figure 7.7a The base of the cranial cavity. View Cribriform plate Ethmoid bone Crista galli Frontal bone Anterior cranial fossa Cribriform foramina Sphenoid Lesser wing Optic canal Greater wing Foramen rotundum Hypophyseal fossa of sella turcica Foramen ovale Foramen spinosum Middle cranial fossa Foramen lacerum Temporal bone (petrous part) Internal acoustic meatus Posterior cranial fossa Jugular foramen Parietal bone Hypoglossal canal Occipital bone Foramen magnum Superior view of the skull, calvaria removed © 2016 Pearson Education, Inc.

Cranium (cont.) Sutural bones Tiny, irregularly shaped bones that appear within sutures Significance is unknown, as not everyone has these © 2016 Pearson Education, Inc.

Figure 7.4b Anterior and posterior views of the skull. Sagittal suture Parietal bone Sutural bone Lambdoid suture Inferior nuchal line Occipital bone Superior nuchal line External occipital protuberance Mastoid process of temporal bone Occipitomastoid suture Occipital condyle External occipital crest Posterior view © 2016 Pearson Education, Inc.

Facial Bones Facial skeleton is made up of 14 bones, 12 of which are paired (mandible and vomer are single) Mandible Maxillary bones (2) Zygomatic bones (2) Nasal bones (2) Lacrimal bones (2) Palatine bones (2) Vomer Inferior nasal conchae (2) © 2016 Pearson Education, Inc.

Facial Bones (cont.) Mandible: largest, strongest bone of face U-shaped lower jawbone made up of body (chin) and two upright rami Mandibular angle: point where rami and chin meet Coronoid process: superior end of rami serves as insertion point for large temporalis muscle Condylar process: posterior to coronoid forms part of temporomandibular joint Mandibular notch: separates processes Body of Mandible Mandibular foramen (for nerves) and mental foramen (for nerves and blood vessels) © 2016 Pearson Education, Inc.

Figure 7.11a Detailed anatomy of the mandible and the maxilla. Mandibular fossa of temporal bone Temporomandibular joint Coronoid process Mandibular notch Condylar process Mandibular foramen Alveolar process Ramus of mandible Mental foramen Mandibular angle Body of mandible Mandible, right lateral view © 2016 Pearson Education, Inc.

Figure 7.4a Anterior and posterior views of the skull. Parietal bone Frontal bone Squamous part of frontal bone Glabella Frontonasal suture Nasal bone Supraorbital foramen (notch) Sphenoid bone (greater wing) Supraorbital margin Superior orbital fissure Temporal bone Optic canal Ethmoid bone Inferior orbital fissure Lacrimal bone Zygomatic bone Middle nasal concha Infraorbital foramen Ethmoid bone Perpendicular plate Maxilla Inferior nasal concha Vomer Mandible Mental foramen Mandibular symphysis Anterior view © 2016 Pearson Education, Inc.

Facial Bones (cont.) Maxillary bones (maxillae): medially fused to form upper jaw and central facial skeleton Palatine process forms two-thirds of hard palate Frontal process: forms lateral bridge of nose Zygomatic processes articulate with zygomatic bones © 2016 Pearson Education, Inc.

Facial Bones (cont.) Openings for nerves and blood vessels include: Inferior orbital fissure Infraorbital foramen © 2016 Pearson Education, Inc.

Figure 7.11b Detailed anatomy of the mandible and the maxilla. Articulates with frontal bone Frontal process Orbital surface Infraorbital foramen Zygomatic process (cut) Anterior nasal spine Alveolar process Maxilla, right lateral view © 2016 Pearson Education, Inc.

Figure 7.4a Anterior and posterior views of the skull. Parietal bone Frontal bone Squamous part of frontal bone Glabella Frontonasal suture Nasal bone Supraorbital foramen (notch) Sphenoid bone (greater wing) Supraorbital margin Superior orbital fissure Temporal bone Optic canal Ethmoid bone Inferior orbital fissure Lacrimal bone Zygomatic bone Middle nasal concha Infraorbital foramen Ethmoid bone Perpendicular plate Maxilla Inferior nasal concha Vomer Mandible Mental foramen Mandibular symphysis Anterior view © 2016 Pearson Education, Inc.

Figure 7.6a Inferior aspect of the skull, mandible removed. Maxilla (palatine process) Incisive fossa Intermaxillary suture Hard palate Median palatine suture Palatine bone (horizontal plate) Infraorbital foramen Maxilla Zygomatic bone Sphenoid bone (greater wing) Temporal bone (zygomatic process) Foramen ovale Vomer Foramen spinosum Foramen lacerum Mandibular fossa Carotid canal External acoustic meatus Styloid process Stylomastoid foramen Mastoid process Jugular foramen Temporal bone (petrous part) Occipital condyle Basilar part of the occipital bone Inferior nuchal line Parietal bone Superior nuchal line External occipital crest Occipital bone External occipital protuberance Foramen magnum Inferior view of the skull (mandible removed) © 2016 Pearson Education, Inc.

Facial Bones (cont.) Zygomatic bones Form cheekbones and inferolateral margins of orbits Articulate with zygomatic processes of temporal, frontal, and maxillary bones © 2016 Pearson Education, Inc.

Figure 7.4a Anterior and posterior views of the skull. Parietal bone Frontal bone Squamous part of frontal bone Glabella Frontonasal suture Nasal bone Supraorbital foramen (notch) Sphenoid bone (greater wing) Supraorbital margin Superior orbital fissure Temporal bone Optic canal Ethmoid bone Inferior orbital fissure Lacrimal bone Zygomatic bone Middle nasal concha Infraorbital foramen Ethmoid bone Perpendicular plate Maxilla Inferior nasal concha Vomer Mandible Mental foramen Mandibular symphysis Anterior view © 2016 Pearson Education, Inc.

Facial Bones (cont.) Nasal bones Form bridge of nose Articulate with frontal, maxillary, and ethmoid bones Attach to cartilage that forms tip of nose © 2016 Pearson Education, Inc.

Facial Bones (cont.) Lacrimal bones Form medial walls of orbits Articulate with frontal, maxillary, and ethmoid bones Lacrimal fossa that houses lacrimal sac allows passageway for tears to drain © 2016 Pearson Education, Inc.

Figure 7.4a Anterior and posterior views of the skull. Parietal bone Frontal bone Squamous part of frontal bone Glabella Frontonasal suture Nasal bone Supraorbital foramen (notch) Sphenoid bone (greater wing) Supraorbital margin Superior orbital fissure Temporal bone Optic canal Ethmoid bone Inferior orbital fissure Lacrimal bone Zygomatic bone Middle nasal concha Infraorbital foramen Ethmoid bone Perpendicular plate Maxilla Inferior nasal concha Vomer Mandible Mental foramen Mandibular symphysis Anterior view © 2016 Pearson Education, Inc.

Occipitomastoid suture Maxilla Figure 7.5a Bones of the lateral aspect of the skull, external and internal views. Coronal suture Frontal bone Sphenoid bone (greater wing) Parietal bone Ethmoid bone Squamous suture Lacrimal bone Lambdoid suture Lacrimal fossa Occipital bone Nasal bone Temporal bone Zygomatic process Zygomatic bone Occipitomastoid suture Maxilla External acoustic meatus Mastoid process Alveolar processes Styloid process Condylar process Mandible Mandibular notch Mental foramen Mandibular ramus External anatomy of the right side of the skull Coronoid process Mandibular angle © 2016 Pearson Education, Inc.

Facial Bones (cont.) Palatine bones Vomer L-shaped bones made from two bony plates Vomer Plow-shaped bone; forms part of nasal septum © 2016 Pearson Education, Inc.

Figure 7.6a Inferior aspect of the skull, mandible removed. Maxilla (palatine process) Incisive fossa Intermaxillary suture Hard palate Median palatine suture Palatine bone (horizontal plate) Infraorbital foramen Maxilla Zygomatic bone Sphenoid bone (greater wing) Temporal bone (zygomatic process) Foramen ovale Vomer Foramen spinosum Foramen lacerum Mandibular fossa Carotid canal External acoustic meatus Styloid process Stylomastoid foramen Mastoid process Jugular foramen Temporal bone (petrous part) Occipital condyle Basilar part of the occipital bone Inferior nuchal line Parietal bone Superior nuchal line External occipital crest Occipital bone External occipital protuberance Foramen magnum Inferior view of the skull (mandible removed) © 2016 Pearson Education, Inc.

Figure 7.14a Bones of the nasal cavity. Frontal sinus Superior, middle, and inferior meatus Superior nasal concha Ethmoid bone Middle nasal concha Inferior nasal concha Nasal bone Anterior nasal spine Maxillary bone (palatine process) Sphenoidal sinus Sphenoid bone Pterygoid process Palatine bone (perpendicular plate) Palatine bone (horizontal plate) Bones forming the left lateral wall of the nasal cavity (nasal septum removed) © 2016 Pearson Education, Inc.

Figure 7.14b Bones of the nasal cavity. Crista galli Ethmoid bone Cribriform plate Frontal sinus Sella turcica Nasal bone Sphenoidal sinus Perpendicular plate of ethmoid bone Septal cartilage Vomer Palatine bone Alveolar process of maxilla Hard palate Palatine process of maxilla Nasal cavity with septum in place showing the contributions of the ethmoid bone, the vomer, and septal cartilage © 2016 Pearson Education, Inc.

The Hyoid Bone Not a bone of skull Lies in anterior neck inferior to mandible Only bone in body that does not articulate directly with another bone Anchored by ligaments Acts as a movable base for tongue and site of attachment for muscles of swallowing and speech © 2016 Pearson Education, Inc.

Greater horn Lesser horn Body Figure 7.12 The hyoid bone. © 2016 Pearson Education, Inc.

Special Characteristics of the Orbits and Nasal Cavity Cavities that encase eyes and lacrimal glands Sites of attachment for eye muscles Formed by parts of seven bones Frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal, and ethmoid © 2016 Pearson Education, Inc.

Figure 7.13a Bones that form the orbits. Photograph, right orbit © 2016 Pearson Education, Inc.

Figure 7.13b Bones that form the orbits. Supraorbital notch Superior orbital fissure Roof of orbit Optic canal • Lesser wing of sphenoid bone Medial wall • Orbital plate of frontal bone • Sphenoid body • Orbital plate of ethmoid bone Lateral wall of orbit • Zygomatic process of frontal bone • Frontal process of maxilla • Lacrimal bone • Greater wing of sphenoid bone Nasal bone • Orbital surface of zygomatic bone Floor of orbit Inferior orbital fissure • Orbital process of palatine bone Infraorbital groove Zygomatic bone • Orbital surface of maxillary bone • Zygomatic bone Infraorbital foramen Contribution of each of the seven bones forming the right orbit © 2016 Pearson Education, Inc.

Special Characteristics of the Orbits and Nasal Cavity (cont.) Nasal cavity: formed by parts of several bones Roof: cribriform plates of ethmoid Lateral walls: superior and middle conchae of ethmoid, perpendicular plates of palatine and Inferior nasal conchae Spaces between conchae called meatuses Conchae increase turbulence of air flow Floor: processes of palatine and maxillary bones Nasal septum Bony posterior formed by vomer and perpendicular plate of ethmoid Anterior formed by septal cartilage © 2016 Pearson Education, Inc.

Figure 7.14a Bones of the nasal cavity. Frontal sinus Superior, middle, and inferior meatus Superior nasal concha Ethmoid bone Middle nasal concha Inferior nasal concha Nasal bone Anterior nasal spine Maxillary bone (palatine process) Sphenoidal sinus Sphenoid bone Pterygoid process Palatine bone (perpendicular plate) Palatine bone (horizontal plate) Bones forming the left lateral wall of the nasal cavity (nasal septum removed) © 2016 Pearson Education, Inc.

Figure 7.14b Bones of the nasal cavity. Crista galli Ethmoid bone Cribriform plate Frontal sinus Sella turcica Nasal bone Sphenoidal sinus Perpendicular plate of ethmoid bone Septal cartilage Vomer Palatine bone Alveolar process of maxilla Hard palate Palatine process of maxilla Nasal cavity with septum in place showing the contributions of the ethmoid bone, the vomer, and septal cartilage © 2016 Pearson Education, Inc.

Special Characteristics of the Orbits and Nasal Cavity (cont.) Paranasal sinuses: formed from five skull bones: frontal, sphenoid, ethmoid, and paired maxillary bones All contain mucosa-lined, air-filled spaces Functions: Warm and humidify air Help to lighten skull Enhance resonance of voice © 2016 Pearson Education, Inc.

Figure 7.15a Paranasal sinuses. Frontal sinus Ethmoidal air cells (sinus) Sphenoidal sinus Maxillary sinus Anterior aspect © 2016 Pearson Education, Inc.

Figure 7.15b Paranasal sinuses. Frontal sinus Ethmoidal air cells Sphenoidal sinus Maxillary sinus Medial aspect © 2016 Pearson Education, Inc.