7 The Skeleton: Part A

Composed of bones, cartilages, joints, ligaments 20% of body mass Skeletal System Composed of bones, cartilages, joints, ligaments 20% of body mass Two major parts Axial Appendicular © 2013 Pearson Education, Inc.

The Axial Skeleton Consists of 80 bones Three major regions Skull Vertebral column Thoracic cage © 2013 Pearson Education, Inc.

Figure 7.1a The human skeleton. Cranium Skull Facial bones Clavicle Scapula Thoracic cage (ribs and sternum) Sternum Rib Humerus Vertebra Vertebral column Radius Ulna Sacrum Carpals Phalanges Metacarpals Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges Anterior view © 2013 Pearson Education, Inc.

Figure 7.1b The human skeleton. Cranium Bones of pectoral girdle Clavicle Scapula Sternum Upper limb Rib Humerus Vertebra Radius Ulna Bones of pelvic girdle Carpals Phalanges Metacarpals Femur Lower limb Tibia Fibula Posterior view © 2013 Pearson Education, Inc.

Formed by two sets of bones The Skull Formed by two sets of bones Cranial bones (cranium) Enclose the brain in the cranial cavity Cranial vault (calvaria) Cranial base: anterior, middle, and posterior cranial fossae Provide sites of attachment for head and neck muscles © 2013 Pearson Education, Inc.

The Skull Facial bones Framework of face Cavities for special sense organs for sight, taste, and smell Openings for air and food passage Sites of attachment for teeth and muscles of facial expression © 2013 Pearson Education, Inc.

Figure 7.2a The skull: Cranial and facial divisions and fossae. Bones of cranium Coronal suture Squamous suture Lambdoid suture Facial bones Cranial and facial divisions of the skull © 2013 Pearson Education, Inc.

Figure 7.2b The skull: Cranial and facial divisions and fossae. Anterior cranial fossa Middle cranial fossa Posterior cranial fossa Superior view of the cranial fossae © 2013 Pearson Education, Inc.

Figure 7.2c The skull: Cranial and facial divisions and fossae. Temporal lobe of cerebrum Frontal lobe of cerebrum Cerebellum Posterior Cranial fossae Middle Anterior Lateral view of cranial fossae showing the contained brain regions © 2013 Pearson Education, Inc.

Middle and internal ear cavities Nasal cavity Orbits 85 named openings Skull Geography Cranial cavity Middle and internal ear cavities Nasal cavity Orbits 85 named openings Foramina, canals, fissures © 2013 Pearson Education, Inc.

Figure 7.3 Major cavities of the skull, frontal section. bone Cranial cavity Frontal sinus Zygomatic bone Orbit Orbit Ethmoidal air cells Ethmoid bone Maxillary sinus Inferior nasal concha Nasal cavity Maxilla Oral cavity Vomer Mandible © 2013 Pearson Education, Inc.

Eight Cranial Bones Frontal bone Parietal bones (2) Occipital bone Temporal bones (2) Sphenoid bone Ethmoid bone © 2013 Pearson Education, Inc.

Anterior portion of cranium Most of anterior cranial fossa Frontal Bone Anterior portion of cranium Most of anterior cranial fossa Superior wall of orbits Contains air-filled frontal sinus © 2013 Pearson Education, Inc.

Figure 7.4 Anatomy of the anterior and posterior aspects of the skull. Frontal bone Parietal bone Glabella Frontonasal suture Squamous part of frontal bone Supraorbital foramen (notch) Nasal bone Supraorbital margin Sphenoid bone (greater wing) Superior orbital fissure Temporal bone Optic canal Ethmoid bone Inferior orbital fissure Lacrimal bone Zygomatic bone Infraorbital foramen Middle nasal concha Ethmoid bone Perpendicular plate Maxilla Inferior nasal concha Vomer Mandible Mental foramen Sagittal suture Sutural bone Parietal bone Mandibular symphysis Anterior view Lambdoid suture Occipital bone Superior nuchal line External occipital protuberance Mastoid process of temporal bone Occipitomastoid suture External occipital crest Occipital condyle Inferior nuchal line Posterior view © 2013 Pearson Education, Inc.

Parietal Bones and Major Associated Sutures Superior and lateral aspects of cranial vault 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 © 2013 Pearson Education, Inc.

External anatomy of the right side of the skull Mandibular angle 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 Temporal bone Lacrimal bone Lambdoid suture Lacrimal fossa Squamous suture Nasal bone Occipital bone Zygomatic process Zygomatic bone Maxilla Occipitomastoid suture External acoustic meatus Alveolar processes Mastoid process Styloid process Condylar process Mandible Mandibular notch Mental foramen Mandibular ramus External anatomy of the right side of the skull Mandibular angle Coronoid process © 2013 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 Ethmoid bone Squamous suture 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 © 2013 Pearson Education, Inc.

(perpendicular plate) Occipitomastoid suture Vomer Incisive fossa Figure 7.5c Bones of the lateral aspect of the skull, external and internal views. Parietal bone Coronal suture Frontal bone Greater wing Sphenoid bone Lesser wing Squamous suture Frontal sinus Temporal bone Crista galli Lambdoid suture Nasal bone Sphenoidal sinus Occipital bone Ethmoid bone (perpendicular plate) Occipitomastoid suture Vomer Incisive fossa External occipital protuberance Maxilla Alveolar processes Internal acoustic meatus Pterygoid process of sphenoid bone 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 © 2013 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) © 2013 Pearson Education, Inc.

Most of skull's posterior wall and posterior cranial fossa Occipital Bone Most of skull's posterior wall and posterior cranial fossa Articulates with 1st vertebra Sites of attachment for ligamentum nuchae and many neck and back muscles © 2013 Pearson Education, Inc.

occipital protuberance Mastoid process of temporal bone Figure 7.4b Anatomy of the anterior and posterior aspects of the skull. Sagittal suture Parietal bone Sutural bone Lambdoid suture Occipital bone Superior nuchal line External occipital protuberance Mastoid process of temporal bone Occipitomastoid suture External occipital crest Occipital condyle Inferior nuchal line Posterior view © 2013 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) © 2013 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 © 2013 Pearson Education, Inc.

Inferolateral aspects of skull and parts of cranial base Temporal Bones Inferolateral aspects of skull and parts of cranial base Four major regions Squamous Tympanic Mastoid Petrous © 2013 Pearson Education, Inc.

Figure 7.8 The temporal bone. External acoustic meatus Squamous part Zygomatic process Petrous part Mandibular fossa Mastoid process Tympanic part Styloid process © 2013 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) © 2013 Pearson Education, Inc.

Figure 7.7a The base of the cranial cavity. Foramen ovale Cribriform plate Crista galli Lesser wing Greater wing View Ethmoid bone Anterior cranial fossa Sphenoid Hypophyseal fossa of sella turcica Middle cranial fossa Temporal bone (petrous part) Posterior cranial fossa Parietal bone Occipital bone Foramen magnum Superior view of the skull, calvaria removed Frontal bone Cribriform foramina Optic canal Foramen rotundum Foramen spinosum Foramen lacerum Internal acoustic meatus Jugular foramen Hypoglossal canal © 2013 Pearson Education, Inc.

Figure 7.7b The base of the cranial cavity. Frontal bone Crista galli 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 Foramen lacerum Middle cranial fossa Temporal bone (petrous part) Posterior cranial fossa Jugular foramen Parietal bone Occipital bone Foramen magnum Superior view of the skull, calvaria removed © 2013 Pearson Education, Inc.

Complex, bat-shaped bone Keystone bone Three pairs of processes Sphenoid Bone Complex, bat-shaped bone Keystone bone Articulates with all other cranial bones Three pairs of processes Greater wings Lesser wings Pterygoid processes © 2013 Pearson Education, Inc.

Figure 7.9a 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 © 2013 Pearson Education, Inc.

Figure 7.9b The sphenoid bone. Body of sphenoid Lesser wing Greater wing Superior orbital fissure Pterygoid process Posterior view © 2013 Pearson Education, Inc.

Superior part of nasal septum, roof of nasal cavities Ethmoid Bone Deepest skull bone Superior part of nasal septum, roof of nasal cavities Contributes to medial wall of orbits Crista galli for dural attachment © 2013 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 © 2013 Pearson Education, Inc.

Frontal bone Parietal bone Glabella Frontonasal suture Squamous part Figure 7.4a Anatomy of the anterior and posterior aspects of the skull. Frontal bone Parietal bone Glabella Frontonasal suture Squamous part of frontal bone Supraorbital foramen (notch) Nasal bone Supraorbital margin Sphenoid bone (greater wing) 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 © 2013 Pearson Education, Inc.

Figure 7.7a The base of the cranial cavity. Foramen ovale Cribriform plate Crista galli Lesser wing Greater wing View Ethmoid bone Anterior cranial fossa Sphenoid Hypophyseal fossa of sella turcica Middle cranial fossa Temporal bone (petrous part) Posterior cranial fossa Parietal bone Occipital bone Foramen magnum Superior view of the skull, calvaria removed Frontal bone Cribriform foramina Optic canal Foramen rotundum Foramen spinosum Foramen lacerum Internal acoustic meatus Jugular foramen Hypoglossal canal © 2013 Pearson Education, Inc.

Tiny irregularly shaped bones that appear within sutures Sutural Bones Tiny irregularly shaped bones that appear within sutures © 2013 Pearson Education, Inc.

occipital protuberance Mastoid process of temporal bone Figure 7.4b Anatomy of the anterior and posterior aspects of the skull. Sagittal suture Parietal bone Sutural bone Lambdoid suture Occipital bone Superior nuchal line External occipital protuberance Mastoid process of temporal bone Occipitomastoid suture External occipital crest Occipital condyle Inferior nuchal line Posterior view © 2013 Pearson Education, Inc.

Fourteen Facial Bones Mandible Maxillary bones (maxillae) (2) Zygomatic bones (2) Nasal bones (2) Lacrimal bones (2) Palatine bones (2) Vomer Inferior nasal conchae (2) © 2013 Pearson Education, Inc.

Largest, strongest bone of face Temporomandibular joint Mandible Lower jaw Largest, strongest bone of face Temporomandibular joint Only freely movable joint in skull © 2013 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 © 2013 Pearson Education, Inc.

Contain maxillary sinuses Maxillary Bones Medially fused to form upper jaw and central portion of facial skeleton Keystone bones Articulate with all other facial bones except mandible Contain maxillary sinuses Largest of paranasal sinuses © 2013 Pearson Education, Inc.

Figure 7.11b Detailed anatomy of the mandible and the maxilla. Articulates withfrontal bone Frontal process Orbital surface Infraorbital foramen Zygomatic process (cut) Anterior nasal spine Alveolar process Maxilla, right lateral view © 2013 Pearson Education, Inc.

Frontal bone Parietal bone Glabella Frontonasal suture Squamous part Figure 7.4a Anatomy of the anterior and posterior aspects of the skull. Frontal bone Parietal bone Glabella Frontonasal suture Squamous part of frontal bone Supraorbital foramen (notch) Nasal bone Supraorbital margin Sphenoid bone (greater wing) 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 © 2013 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) © 2013 Pearson Education, Inc.

Inferolateral margins of orbits Zygomatic Bones Cheekbones Inferolateral margins of orbits © 2013 Pearson Education, Inc.

Frontal bone Parietal bone Glabella Frontonasal suture Squamous part Figure 7.4a Anatomy of the anterior and posterior aspects of the skull. Frontal bone Parietal bone Glabella Frontonasal suture Squamous part of frontal bone Supraorbital foramen (notch) Nasal bone Supraorbital margin Sphenoid bone (greater wing) 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 © 2013 Pearson Education, Inc.

Nasal Bones and Lacrimal Bones Form bridge of nose Lacrimal bones In medial walls of orbits Lacrimal fossa houses lacrimal sac © 2013 Pearson Education, Inc.

External anatomy of the right side of the skull Mandibular angle 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 Temporal bone Lacrimal bone Lambdoid suture Lacrimal fossa Squamous suture Nasal bone Occipital bone Zygomatic process Zygomatic bone Maxilla Occipitomastoid suture External acoustic meatus Alveolar processes Mastoid process Styloid process Condylar process Mandible Mandibular notch Mental foramen Mandibular ramus External anatomy of the right side of the skull Mandibular angle Coronoid process © 2013 Pearson Education, Inc.

Palatine Bones and Vomer Posterior one-third of hard palate Posterolateral walls of the nasal cavity Small part of the orbits Vomer Plow shaped Inferior part of nasal septum © 2013 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) © 2013 Pearson Education, Inc.

Figure 7.13b 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 © 2013 Pearson Education, Inc.

Inferior Nasal Conchae Form part of lateral walls of nasal cavity Largest of three pairs of conchae © 2013 Pearson Education, Inc.

Figure 7.13a 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) © 2013 Pearson Education, Inc.

Cavities that encase eyes and lacrimal glands Orbits 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 © 2013 Pearson Education, Inc.

Figure 7.12a Bones that form the orbits. Photograph, right orbit © 2013 Pearson Education, Inc.

Figure 7.12b Bones that form the orbits. Superior orbital fissure Roof of orbit Supraorbital notch Optic canal • Lesser wing of sphenoid bone • Orbital plate of frontal bone Medial wall • Sphenoid body • Orbital plate of ethmoid bone Lateral wall of orbit • Zygomatic process of frontal bone • Frontal process of maxilla • Greater wing of sphenoid bone • Lacrimal bone • Orbital surface of zygomatic bone Nasal bone Inferior orbital fissure Floor of orbit Infraorbital groove • Orbital process of palatine bone Zygomatic bone • Orbital surface of maxillary bone Infraorbital foramen • Zygomatic bone Contribution of each of the seven bones forming the right orbit © 2013 Pearson Education, Inc.

Nasal Cavity Roof, lateral walls, and floor formed by parts of four bones Ethmoid Palatine bones Maxillary bones Inferior nasal conchae Nasal septum of bone and hyaline cartilage Perpendicular plate of ethmoid Vomer Anterior septal cartilage © 2013 Pearson Education, Inc.

Figure 7.13a 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) © 2013 Pearson Education, Inc.

Figure 7.13b 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 © 2013 Pearson Education, Inc.

Mucosa-lined, air-filled spaces Lighten skull Paranasal Sinuses Mucosa-lined, air-filled spaces Lighten skull Enhance resonance of voice Warm and humidify air Found in frontal, sphenoid, ethmoid, and maxillary bones © 2013 Pearson Education, Inc.

Figure 7.14a Paranasal sinuses. Frontal sinus Ethmoidal air cells (sinus) Sphenoidal sinus Maxillary sinus Anterior aspect © 2013 Pearson Education, Inc.

Figure 7.14b Paranasal sinuses. Frontal sinus Ethmoidal air cells Sphenoidal sinus Maxillary sinus Medial aspect © 2013 Pearson Education, Inc.

Does not articulate directly with another bone Movable base for tongue Hyoid Bone Not bone of skull Does not articulate directly with another bone Movable base for tongue Site of attachment for muscles of swallowing and speech © 2013 Pearson Education, Inc.

Figure 7.15 The hyoid bone, anterior view. Greater horn Lesser horn Body © 2013 Pearson Education, Inc.