7 The Axial Skeleton PowerPoint Lecture Presentations prepared by Jason LaPres Lone Star College North Harris
An Introduction to the Axial Skeleton Learning Outcomes 7-1 Identify the bones of the axial skeleton, and specify their functions. 7-2 Identify the bones of the cranium and face, and explain the significance of the markings on the individual bones. 7-3 Identify the foramina and fissures of the skull, and cite the major structures using the passageways. 7-4 Describe the structure and functions of the orbital complex, nasal complex, and paranasal sinuses.
An Introduction to the Axial Skeleton Learning Outcomes 7-5 Describe the key structural differences among the skulls of infants, children, and adults. 7-6 Identify and describe the curvatures of the spinal column, and indicate the function of each. 7-7 Identify the vertebral regions, and describe the distinctive structural and functional characteristics of vertebrae in each region. 7-8 Explain the significance of the articulations between the thoracic vertebrae and the ribs, and between the ribs and sternum.
An Introduction to the Axial Skeleton Structures of Bones Articulations Contacts with other bones Landmarks (bone markings; marks) Areas of muscle and ligament attachment Foramina Openings for nerves and blood vessels
7-1 The Axial Skeleton The Axial Skeleton Forms the longitudinal axis of the body Has 80 bones The skull 8 cranial bones 14 facial bones Bones associated with the skull 6 auditory ossicles The hyoid bone
7-1 The Axial Skeleton The Axial Skeleton The vertebral column 24 vertebrae (singular = vertebra) The sacrum The coccyx The thoracic cage 24 ribs The sternum
Figure 7-1a The Axial Skeleton SKELETAL SYSTEM 206 APPENDICULAR SKELETON (see Figure 8 1) AXIAL SKELETON 80 8 14 6 1 Cranium Face Auditory ossicles Hyoid Skull Associated bones 29 Skull and associated bones 1 24 Sternum Ribs 25 Thoracic cage 24 Vertebrae 1 Sacrum 26 Vertebral column 1 Coccyx An anterior view of the entire skeleton, with the axial components highlighted. The numbers in the boxes indicate the number of bones in the adult skeleton.
Figure 7-1b The Axial Skeleton Skull Cervical vertebrae Sternum Ribs Thoracic vertebrae Costal cartilages Lumbar vertebrae Sacrum Coccyx Anterior (left) and posterior (right) views of the axial skeleton. The individual bones associated with the skull are not visible.
7-1 The Axial Skeleton Functions of the Axial Skeleton Supports and protects organs in body cavities 1. Attaches to muscles of head, neck, and trunk 2. Performs respiratory movements 3. Stabilizes parts of appendicular skeleton
7-2 The Skull The Skull Protects: The brain Entrances to respiratory system Entrance to digestive system Contains: 22 bones 8 cranial bones Form the braincase or cranium 14 facial bones Protect and support entrances to digestive and respiratory tracts
Figure 7-2 Cranial and Facial Subdivisions of the Skull SKULL FACE 14 CRANIUM 8 ASSOCIATED BONES 7 Maxillary bones 2 Occipital bone 1 Palatine bones Nasal bones Inferior nasal conchae Zygomatic bones Lacrimal bones 2 2 2 2 2 Parietal bones Frontal bone Temporal bones Sphenoid Ethmoid 2 1 2 1 1 Hyoid bone 1 Auditory ossicles enclosed in temporal bones (detailed in Chapter 17) 6 Vomer 1 Mandible 1
Figure 7-2 Cranial and Facial Subdivisions of the Skull FRONTAL BONE PARIETAL BONE NASAL BONE ZYGOMATIC BONE MAXILLA LACRIMAL BONE SPHENOID ETHMOID VOMER TEMPORAL BONE Cranial bones OCCIPITAL BONE MANDIBLE Facial bones
7-2 The Skull Cranial Bones Enclose the cranial cavity Which contains the brain And its fluids, blood vessels, nerves, and membranes
7-2 The Skull Facial Bones Superficial facial bones For muscle attachment Deep facial bones Separate the oral and nasal cavities Form the nasal septum
Figure 7-3a The Adult Skull PARIETAL BONE (left) PARIETAL BONE (right) Sagittal suture Lambdoid suture OCCIPITAL BONE Squamous suture TEMPORAL BONE Mastoid process Styloid process Occipital condyle External occipital protuberance MANDIBLE Posterior view
Figure 7-3b The Adult Skull OCCIPITAL BONE Lambdoid suture PARIETAL BONE (right) PARIETAL BONE (left) Sagittal suture Coronal suture FRONTAL BONE ZYGOMATIC BONE NASAL BONES Superior view
Figure 7-3c The Adult Skull Coronal suture PARIETAL BONE FRONTAL BONE SPHENOID Squamous suture Supra-orbital foramen Squamous part of temporal bone Lambdoid suture External acoustic meatus OCCIPITAL BONE TEMPORAL BONE NASAL BONE LACRIMAL BONE ETHMOID Infra-orbital foramen MAXILLA ZYGOMATIC BONE Mastoid process Zygomatic arch Styloid process Zygomatic process of temporal bone Temporal process of zygomatic bone Lateral view MANDIBLE Mental foramen Mental protuberance
Figure 7-3d The Adult Skull PARIETAL BONE Coronal suture SPHENOID FRONTAL BONE TEMPORAL BONE ETHMOID PALATINE BONE LACRIMAL BONE ZYGOMATIC BONE NASAL BONE MAXILLA INFERIOR NASAL CONCHA MANDIBLE Supra-orbital foramen Optic canal Superior orbital fissure Inferior orbital fissure Temporal process of zygomatic bone Mastoid process of temporal bone Infra-orbital foramen Middle nasal concha (part of ethmoid) Perpendicular plate of ethmoid VOMER Mental protuberance Bony nasal septum Mental foramen Anterior view
Figure 7-3e The Adult Skull FRONTAL BONE ZYGOMATIC BONE VOMER SPHENOID Foreman ovale Styloid process Mandibular fossa External acoustic meatus Jugular foramen MAXILLA PALATINE BONE Zygomatic arch Medial and lateral pterygoid processes Foramen lacerum Carotid canal TEMPORAL BONE Mastoid process Stylomastoid foramen Lambdoid suture OCCIPITAL BONE External occipital protuberance Occipital condyle Foramen magnum Inferior view
Figure 7-4a The Sectional Anatomy of the Skull Coronal suture FRONTAL BONE SPHENOID Sphenoidal sinus (right) Frontal sinus Crista galli NASAL BONE ETHMOID VOMER PALATINE BONE MAXILLA MANDIBLE PARIETAL BONE Squamous suture TEMPORAL BONE Lambdoid suture Hypophyseal fossa of sella turcica Internal acoustic meatus OCCIPITAL BONE Hypoglossal canal Styloid process Medial view of a sagittal section through the skull.
Figure 7-4b The Sectional Anatomy of the Skull FRONTAL BONE ETHMOID SPHENOID TEMPORAL BONE Carotid canal PARIETAL BONE Internal occipital crest OCCIPITAL BONE Foramen magnum Crista galli Cribriform plate Sella turcica Foramen rotundum Foramen lacerum Foramen ovale Foramen spinosum Internal acoustic meatus Jugular foramen Hypoglossal canal Superior view of a horizontal section through the skull, showing the floor of the cranial cavity. Compare with part (a) and with Figure 7 3e.
7-2 The Skull Superficial Facial Bones Maxillae = maxillary bones Lacrimal Nasal Zygomatic Mandible Deep Facial Bones Palatine Inferior nasal conchae Vomer
7-2 The Skull Sinuses Cavities that decrease the weight of the skull 1. Lined with mucous membranes 2. Protect the entrances of the respiratory system
7-2 The Skull Sutures The immovable joints of the skull The four major sutures 1. Lambdoid suture 2. Coronal suture 3. Sagittal suture 4. Squamous suture
7-2 The Skull Lambdoid Suture Separates occipital from parietal bones May contain sutural (Wormian) bones Coronal Suture Attaches frontal bone to parietal bones The calvaria (skullcap) Consists of occipital, parietal, and frontal bones
7-2 The Skull Sagittal Suture Between the parietal bones From lambdoid suture to coronal suture Squamous Sutures Form boundaries between temporal bones and parietal bones
7-3 The Cranial Bones of the Skull The Cranial Bones Occipital bone Parietal bones Frontal bone Temporal bones Sphenoid Ethmoid
7-3 The Cranial Bones of the Skull The Occipital Bone Functions of the occipital bone Forms the posterior and inferior surfaces of the cranium Articulations of the occipital bone Parietal bones Temporal bones Sphenoid First cervical vertebra (atlas)
7-3 The Cranial Bones of the Skull The Occipital Bone Marks of the occipital bone External occipital protuberance External occipital crest Occipital condyles articulate with neck Inferior and superior nuchal lines: attachment site of muscles and ligaments
7-3 The Cranial Bones of the Skull The Occipital Bone Foramina of the occipital bone Foramen magnum connects cranial and spinal cavities Jugular foramen for jugular vein Hypoglossal canals for hypoglossal nerves
Figure 7-5a The Occipital and Parietal Bones Hypoglossal canal Occipital condyle Foramen magnum Inferior nuchal line External occipital protuberance External occipital crest Superior nuchal line Occipital bone, inferior view
7-3 The Cranial Bones of the Skull The Parietal Bones Functions of the parietal bones Form part of the superior and lateral surfaces of the cranium Articulations of the parietal bones Other parietal bone Occipital bone Temporal bone Frontal bone Sphenoid
7-3 The Cranial Bones of the Skull The Parietal Bones Marks of the parietal bones Superior and inferior temporal lines To attach temporalis muscle Grooves for cranial blood vessels
Figure 7-5b The Occipital and Parietal Bones Superior temporal line Inferior temporal line Right parietal bone, lateral view
7-3 The Cranial Bones of the Skull The Frontal Bone Functions of the frontal bone Forms the anterior cranium and upper eye sockets Contains frontal sinuses Articulations of the frontal bone Parietal bone Maxillary Metopic suture Ethmoid Lacrimal bone Zygomatic bone Sphenoid Nasal bone
7-3 The Cranial Bones of the Skull The Frontal Bone Marks of the frontal bone Frontal squama (forehead) Supra-orbital margin (protects eye) Lacrimal fossa (for tear ducts) Frontal sinuses
7-3 The Cranial Bones of the Skull The Frontal Bone Foramina of the frontal bone Supra-orbital foramen For blood vessels of eyebrows, eyelids, and frontal sinuses Supra-orbital notch An incomplete supra-orbital foramen
Figure 7-6a The Frontal Bone Frontal squama Frontal (metopic) suture Superior temporal line Supra-orbital margin Anterior surface Supra-orbital notch
Figure 7-6b The Frontal Bone Supra-orbital foramen Lacrimal fossa Frontal sinus Supra-orbital margin Inferior (orbital) surface
7-3 The Cranial Bones of the Skull The Temporal Bones Functions of the temporal bones 1. Part of lateral walls of cranium and zygomatic arches 2. Articulate with mandible 3. Surround and protect inner ear 4. Attach muscles of jaws and head
7-3 The Cranial Bones of the Skull The Temporal Bones Articulations of the temporal bones Zygomatic bone Sphenoid Parietal bone Occipital bone Mandible
7-3 The Cranial Bones of the Skull The Temporal Bones Marks of the temporal bones Squamous part Zygomatic process Mandibular fossa Mastoid process Styloid process Petrous part Auditory ossicles
7-3 The Cranial Bones of the Skull Squamous Part Borders the squamous suture Zygomatic Process Inferior to the squamous portion Articulates with temporal process of zygomatic bone Forms zygomatic arch (cheekbone) Mandibular Fossa Articulates with the mandible
7-3 The Cranial Bones of the Skull Mastoid Process For muscle attachment Contains mastoid air cells connected to middle ear Styloid Process To attach tendons and ligaments of the hyoid, tongue, and pharynx Petrous Part Encloses structures of the inner ear
7-3 The Cranial Bones of the Skull Auditory Ossicles Three tiny bones in tympanic cavity (middle ear) Transfer sound from tympanic membrane (eardrum) to inner ear
7-3 The Cranial Bones of the Skull The Temporal Bones Foramina of the temporal bones Carotid canal for internal carotid artery Foramen lacerum For carotid and small arteries Hyaline cartilage Auditory tube
7-3 The Cranial Bones of the Skull The Temporal Bones Foramina of the temporal bones External acoustic meatus (canal) ends at tympanic membrane Stylomastoid foramen for facial nerve Internal acoustic meatus (canal) For blood vessels and nerves of the inner ear Facial nerve
Figure 7-7a The Temporal Bones Petrous part Squamous part Internal acoustic meatus Mastoid process Zygomatic process Medial view of the right temporal bone Styloid process
Figure 7-7b The Temporal Bones Squamous part External acoustic meatus Mandibular fossa Zygomatic process Mastoid process Styloid process Lateral view of the right temporal bone
Figure 7-7c The Temporal Bones External acoustic meatus Mastoid process, cut to show mastoid air cells A cutaway view of the mastoid air cells
7-3 The Cranial Bones of the Skull The Sphenoid Functions of the sphenoid Part of the floor of the cranium Unites cranial and facial bones Strengthens sides of the skull Contains sphenoidal sinuses
7-3 The Cranial Bones of the Skull The Sphenoid Articulations of the sphenoid Ethmoid Frontal bone Occipital bone Parietal bone Temporal bone Palatine bones Zygomatic bones Maxillae Vomer
7-3 The Cranial Bones of the Skull The Sphenoid Marks of the sphenoid Sphenoid body Sella turcica Hypophyseal fossa Sphenoidal sinuses Lesser wings Greater wings Pterygoid processes
7-3 The Cranial Bones of the Skull Sphenoid Body At the central axis of the sphenoid Sella Turcica Saddle-shaped enclosure On the superior surface of the body Hypophyseal Fossa A depression within the sella turcica Holds the pituitary gland
7-3 The Cranial Bones of the Skull Sphenoidal Sinuses On either side of the body Inferior to the sella turcica Lesser Wings Anterior to the sella turcica
7-3 The Cranial Bones of the Skull Greater Wings Form part of the cranial floor Sphenoidal spine Posterior wall of the orbit Pterygoid Processes Form pterygoid plates To attach muscles of the lower jaw and soft palate
7-3 The Cranial Bones of the Skull The Sphenoid Foramina of the sphenoid Optic canals for optic nerves Superior orbital fissure for blood vessels and nerves of the orbit Foramen rotundum for blood vessels and nerves of the face Foramen ovale for blood vessels and nerves of the face Foramen spinosum for blood vessels and nerves of the jaws
Figure 7-8a The Sphenoid Foramen rotundum Optic Optic groove canal Lesser wing Foramen ovale Foramen spinosum Sella turcica Superior surface Greater wing Sphenoidal spine
Figure 7-8b The Sphenoid Superior Sphenoidal orbital fissure sinus Lesser wing Greater wing Orbital surface Body Foramen rotundum Pterygoid plates Pterygoid process Anterior surface
7-3 The Cranial Bones of the Skull The Ethmoid Functions of the ethmoid Forms anteromedial floor of the cranium Roof of the nasal cavity Part of the nasal septum and medial orbital wall Contains ethmoidal air cells (network of sinuses)
7-3 The Cranial Bones of the Skull The Ethmoid Articulations of the ethmoid Frontal bone Sphenoid Nasal bone Lacrimal bone Palatine bone Maxillary bones Inferior nasal conchae Vomer
7-3 The Cranial Bones of the Skull The Ethmoid Three parts of the ethmoid 1. The cribriform plate 2. The two lateral masses 3. The perpendicular plate
7-3 The Cranial Bones of the Skull The Cribriform Plate Floor of the cranium Roof of the nasal cavity Contains the crista galli The Two Lateral Masses Ethmoidal labyrinth (ethmoidal air cells) Superior nasal conchae Middle nasal conchae The Perpendicular Plate Part of the nasal septum
7-3 The Cranial Bones of the Skull The Ethmoid Foramina of the ethmoid Olfactory foramina In the cribriform plate For olfactory nerves
Figure 7-9a The Ethmoid Olfactory foramina Cribriform plate Lateral mass containing ethmoidal labyrinth Crista galli Superior surface Perpendicular plate
Figure 7-9b The Ethmoid Crista galli Superior nasal concha Perpendicular plate Middle nasal concha Posterior surface
7-3 The Facial Bones of the Skull The Facial Bones Maxillae (maxillary bones) Palatine bones Nasal bones Vomer Inferior nasal conchae Zygomatic bones Lacrimal bones Mandible
7-3 The Facial Bones of the Skull The Maxillae Functions of the maxillae Support upper teeth Form inferior orbital rim Form lateral margins of external nares Form upper jaw and hard palate Contain maxillary sinuses (largest sinuses)
7-3 The Facial Bones of the Skull The Maxillae Articulations of the maxillae Frontal bones Ethmoid With one another All other facial bones except the mandible
7-3 The Facial Bones of the Skull The Maxillae Marks of the maxillae Orbital rim protects eye and orbit Anterior nasal spine attaches cartilaginous anterior nasal septum Alveolar processes border the mouth and support upper teeth Palatine processes form the hard palate (roof of mouth) Maxillary sinuses lighten bone Nasolacrimal canal protects lacrimal sac and nasolacrimal duct
7-3 The Facial Bones of the Skull The Maxillae Foramina of the maxillae Infra-orbital foramen For sensory nerve to brain (via foramen rotundum of sphenoid) Inferior orbital fissure For cranial nerves and blood vessels
Figure 7-10a The Maxillae and Palatine Bones Orbital rim Zygomatic process Alveolar process Infra-orbital foramen Anterior nasal spine An anterolateral view of the right maxilla.
7-3 The Facial Bones of the Skull The Palatine Bones Functions of the palatine bones Form the posterior portion of the hard palate Contribute to the floors of the orbits
7-3 The Facial Bones of the Skull The Palatine Bones Articulations of the palatine bones With other palatine bone Maxillae Sphenoid Ethmoid Inferior nasal conchae Vomer
7-3 The Facial Bones of the Skull The Palatine Bones Divisions of the palatine bones Horizontal plate: posterior part of hard palate Perpendicular plate from horizontal plate to orbital process of orbit floor Foramina of the palatine bones Many in the lateral portion of the horizontal plate For small blood vessels and nerves of the roof of the mouth
Figure 7-10b The Maxillae and Palatine Bones Palatine bone (horizontal plate) Palatine process Alveolar process Maxillary sinus Superior view of a horizontal section through right maxilla and palatine bone; note the size and orientation of the maxillary sinus.
Figure 7-10c The Maxillae and Palatine Bones Orbital process Horizontal plate Perpendicular plate An anterior view of the two palatine bones.
7-3 The Facial Bones of the Skull The Nasal Bones Functions of the nasal bones Support the bridge of the nose Connect to cartilages of the distal part of the nose (external nares)
7-3 The Facial Bones of the Skull The Nasal Bones Articulations of the nasal bones With other nasal bones Ethmoid Frontal bones Maxillae
7-3 The Facial Bones of the Skull The Vomer Functions of the vomer Forms the inferior portion of the bony nasal septum Articulations of the vomer Sphenoid Ethmoid Palatine bones Maxillae Cartilaginous part of the nasal septum
7-3 The Facial Bones of the Skull The Inferior Nasal Conchae Functions of the inferior nasal conchae To create air turbulence in the nasal cavity To increase the epithelial surface area To warm and humidify inhaled air
7-3 The Facial Bones of the Skull The Inferior Nasal Conchae Articulations of the inferior nasal conchae Ethmoid Maxillae Palatine bones Lacrimal bones
7-3 The Facial Bones of the Skull The Zygomatic Bones Functions of the zygomatic bones Contribute to the rim and lateral wall of the orbit Form part of the zygomatic arch Articulations of the zygomatic bones Sphenoid Frontal bone Temporal bones Maxillae
7-3 The Facial Bones of the Skull The Zygomatic Bones Marks of the zygomatic bones Temporal process Meets the zygomatic process of the temporal bone Foramina of the zygomatic bones Zygomaticofacial foramen For sensory nerves of cheeks
7-3 The Facial Bones of the Skull The Lacrimal Bones Functions of the lacrimal bones The smallest facial bones Form part of the medial wall of the orbit Articulations of the lacrimal bones Frontal bone Maxillae Ethmoid
7-3 The Facial Bones of the Skull The Lacrimal Bones Marks of the lacrimal bones Lacrimal sulcus Location of the lacrimal sac Leads to the nasolacrimal canal (between orbit and nasal cavity)
Figure 7-11 The Smaller Bones of the Face Supra-orbital foramen NASAL BONE SPHENOID TEMPORAL BONE Zygomaticofacial foramen ZYGOMATIC BONE Infra-orbital foramen MAXILLA Perpendicular plate of ethmoid VOMER Bony nasal septum
Figure 7-11 The Smaller Bones of the Face Lacrimal sulcus Optic canal Superior orbital fissure LACRIMAL BONE Middle nasal concha INFERIOR NASAL CONCHA Temporal process of zygomatic bone Mastoid process Perpendicular plate of ethmoid VOMER Bony nasal septum
7-3 The Facial Bones of the Skull The Mandible Functions of the mandible Forms the lower jaw Articulations of the mandible Mandibular fossae of the temporal bones
7-3 The Facial Bones of the Skull The Mandible Marks of the mandible Body of the mandible horizontal portion Alveolar processes support the lower teeth Mental protuberance attaches facial muscles A depression on the medial surface for submandibular salivary gland Mylohyoid line for insertion of the mylohyoid muscle (floor of mouth)
7-3 The Facial Bones of the Skull The Mandible Marks of the mandible Ramus ascending from the mandibular angle on either side Condylar process articulates with temporal bone at temporomandibular joint Coronoid process: insertion point for temporalis muscle (closes the jaws) Mandibular notch separates condylar and coronoid processes
7-3 The Facial Bones of the Skull The Mandible Foramina of the mandible Mental foramina For sensory nerves of lips and chin Mandibular foramen Entrance to the mandibular canal For blood vessels and nerves of lower teeth
7-3 The Facial Bones of the Skull The Hyoid Bone Functions of the hyoid bone Supports the larynx Attaches muscles of the larynx, pharynx, and tongue Articulations of the hyoid bone Connects lesser horns to styloid processes of temporal bones
7-3 The Facial Bones of the Skull The Hyoid Bone Marks of the hyoid bone Body of the hyoid Attaches muscles of larynx, tongue, and pharynx
7-3 The Facial Bones of the Skull The Hyoid Bone Marks of the hyoid bone Greater horns (greater cornua) Support larynx Attach muscles of the tongue Lesser horns (lesser cornua) Attach stylohyoid ligaments Support hyoid and larynx
Figure 7-12a The Mandible and Hyoid Bone Articular surface for temporomandibular joint Coronoid process Head Condylar process Mandibular notch Angle Ramus Body A lateral and slightly superior view of the mandible Teeth Alveolar process Mental protuberance Mental foramen
Figure 7-12b The Mandible and Hyoid Bone Alveolar process Articular surface Condylar process Coronoid process Mandibular foramen Mylohyoid line Depression for submandibular salivary gland A medial view of the right mandible
Figure 7-12c The Mandible and Hyoid Bone Greater horn Lesser horn Body An anterior view of the hyoid bone
7-4 The Orbital and Nasal Complexes The Eye Sockets (Orbits) Frontal bone (roof) Maxilla (floor) Maxillary, lacrimal, and ethmoid bones (orbital rim and medial wall) Sphenoid and palatine bones
Figure 7-13 The Orbital Complex FRONTAL BONE SPHENOID Supra-orbital notch Optic canal Superior orbital fissure Inferior orbital fissure ZYGOMATIC BONE Infra-orbital groove Infra-orbital foramen MAXILLA ETHMOID LACRIMAL BONE Lacrimal sulcus Nasolacrimal canal PALATINE BONE
Figure 7-13 The Orbital Complex Supra-orbital notch FRONTAL BONE SPHENOID Optic canal Superior orbital fissure ETHMOID Nasolacrimal canal Inferior orbital fissure Infra-orbital groove ZYGOMATIC BONE MAXILLA Infra-orbital foramen
7-4 The Orbital and Nasal Complexes Bones of the Nasal Cavities and Paranasal Sinuses Make Up the Nasal Complex Frontal bone, sphenoid, and ethmoid Superior wall of nasal cavities Maxillae, lacrimal bones, ethmoid, and inferior nasal conchae Lateral walls of nasal cavities Maxillae and nasal bones Bridge of nose
Figure 7-14a The Nasal Complex FRONTAL BONE Frontal sinuses ETHMOID NASAL BONE PALATINE BONE (bony palate) MAXILLA (bony palate) Sphenoidal sinuses Superior Middle A sagittal section through the skull, with the nasal septum removed to show major features of the wall of the right nasal cavity. The sphenoidal sinuses are visible. SPHENOID INFERIOR NASAL CONCHA Nasal conchae of ethmoid
Figure 7-14b The Nasal Complex FRONTAL BONE Cranial cavity Ethmoidal air cell Perpendicular plate of ethmoid Maxillary sinus VOMER Frontal sinus Right orbit Superior nasal concha Middle nasal concha ZYGOMATIC BONE INFERIOR NASAL CONCHA MAXILLA (bony palate) Tongue MANDIBLE A frontal section through the ethmoidal air cells and maxillary sinuses, part of the paranasal sinuses.
7-4 The Orbital and Nasal Complexes Paranasal Sinuses Air-filled chambers connected to the nasal cavities Lighten skull bones Provide mucous epithelium (flushes nasal cavities)
7-5 Fontanelles The Infant Skull Grows rapidly Is large compared to the body Has many ossification centers
7-5 Fontanelles The Infant Skull Fusion is not complete at birth Two frontal bones Four occipital bones Several sphenoidal and temporal elements
7-5 Fontanelles Fontanelles Are areas of fibrous connective tissue (soft spots) Cover unfused sutures in the infant skull Allow the skull to flex during birth
7-5 Fontanelles Anterior Fontanelle Frontal, sagittal, and coronal sutures Occipital Fontanelle Lambdoid and sagittal sutures Sphenoidal Fontanelles Squamous and coronal sutures Mastoid Fontanelles Squamous and lambdoid sutures
Figure 7-15a The Skull of an Infant Coronal suture FRONTAL BONE PARIETAL BONE Sphenoidal fontanelle NASAL BONE MAXILLA Squamous suture Lambdoid suture OCCIPITAL BONE SPHENOID MANDIBLE Lateral view TEMPORAL BONE Mastoid fontanelle
Figure 7-15b The Skull of an Infant Coronal suture FRONTAL BONE Frontal suture Anterior fontanelle FRONTAL BONE PARIETAL BONE Sagittal suture PARIETAL BONE Lambdoid suture OCCIPITAL BONE Superior view Occipital fontanelle
7-6 The Vertebral Column The Vertebral Column (Spine) Protects the spinal cord Supports the head and body 26 bones 24 vertebrae, the sacrum, and the coccyx
Figure 7-16 The Vertebral Column Spinal Curves Primary curves develop before birth, and secondary curves after birth. The cervical curve, a secondary curve, develops as the infant learns to balance the weight of the head on the vertebrae of the neck. Vertebral Regions Regions are defined by anatomical characteristics of individual vertebrae. Cervical (7 vertebrae) The thoracic curve, a primary curve, accommodates the thoracic organs. Thoracic (12 vertebrae) The lumbar curve, a secondary curve, balances the weight of the trunk over the lower limbs; it develops with the ability to stand. Lumbar (5 vertebrae) The sacral curve, a primary curve, accommodates the abdominopelvic organs. Sacral Coccygeal
7-6 The Vertebral Column Vertebrae The neck Seven cervical vertebrae The upper back 12 thoracic vertebrae Each articulates with one or more pair of ribs The lower back Five lumbar vertebrae
7-6 The Vertebral Column The Sacrum and Coccyx The fifth lumbar vertebra articulates with the sacrum The sacrum articulates with the coccyx
7-6 The Vertebral Column Four Spinal Curves 1. Cervical curve 2. Thoracic curve 3. Lumbar curve 4. Sacral curve
7-6 The Vertebral Column Thoracic and Sacral Curves Are called primary curves (present during fetal development) Or accommodation curves (accommodate internal organs) Lumbar and Cervical Curves Are called secondary curves (appear after birth) Or compensation curves (shift body weight for upright posture)
Figure 7-17a Abnormal Curvatures of the Spine Kyphosis
Figure 7-17b Abnormal Curvatures of the Spine Lordosis
Figure 7-17c Abnormal Curvatures of the Spine Scoliosis
7-6 The Vertebral Column Vertebral Anatomy The vertebral body (centrum) Transfers weight along the spine The vertebral arch Posterior margin of vertebral foramen The articular processes Lateral projections between laminae and pedicles
Figure 7-18a Vertebral Anatomy Articular processes Vertebral arch Vertebral body The major components of a typical vertebra
7-6 The Vertebral Column Vertebral Anatomy The vertebral arch Pedicles Walls of the vertebral arch Laminae Roof of the vertebral arch
7-6 The Vertebral Column Vertebral Anatomy The vertebral arch Spinous process Projection where vertebral laminae fuse Transverse process Projection where laminae join pedicles
7-6 The Vertebral Column Vertebral Anatomy The articular processes Superior articular process Inferior articular process Have articular facets on articular faces
Figure 7-18b Vertebral Anatomy Superior articular process Transverse process Pedicle Vertebral body Spinous process Inferior articular facet Inferior articular process Arrow passing through vertebral foramen A lateral and slightly inferior view of a vertebra
Figure 7-18c Vertebral Anatomy Transverse process Superior articular process Spinous process Inferior articular process Inferior articular facet Vertebral foramen Vertebral body Pedicle An inferior view of a vertebra
7-6 The Vertebral Column Vertebral Foramina Intervertebral foramina Gaps between pedicles of adjacent vertebrae For nerve connections to spinal cord Vertebral canal Formed by vertebral foramina Encloses the spinal cord
7-6 The Vertebral Column Intervertebral Discs Are pads of fibrocartilage Separate the vertebral bodies Absorb shocks
Figure 7-18d Vertebral Anatomy Superior articular facets Superior articular process Lamina of vertebral arch Spinous process Intervertebral disc Transverse process Vertebral body An posterior view of three articulated vertebrae Inferior articular process
Figure 7-18e Vertebral Anatomy Superior articular facets Lamina of vertebral arch Intervertebral foramen Intervertebral disc Spinous process Transverse process Vertebral body Inferior articular facet Arrow passing through vertebral canal A lateral and sectional view of three articulated vertebrae
7-7 Vertebral Regions Vertebral Regions Vertebrae are numbered By region, from top (superior) to bottom (inferior) C 1 articulates with skull, L 5 with sacrum Vertebrae of each region Have characteristics determined by functions
7-7 Vertebral Regions Regions of the Vertebral Column Cervical (C) Thoracic (T) Lumbar (L) Sacral (S) Coccygeal (Co)
7-7 Vertebral Regions The Cervical Vertebrae Small body (support only head) Large vertebral foramen (largest part of spinal cord) Concave superior surface Slope posterior to anterior C 1 (atlas) has no spinous process All others have short spinous processes Tip of each spinous process is notched (bifid)
Figure 7-19a The Cervical Vertebrae C 1 C 2 C 3 C 4 C 5 Spinous process of vertebra prominens C 7 C 6 A lateral view of the cervical vertebrae, C 1 C 7
Figure 7-19b The Cervical Vertebrae Vertebral arch Vertebral foramen Spinous process Lamina Superior articular process Pedicle Transverse process Costal process Vertebral body Transverse foramen A superior view of a representative cervical vertebra showing characteristics of C 3 C 6. Notice the typical features listed in Table 7 2. Superior articular facet
Figure 7-19c The Cervical Vertebrae Transverse process Inferior articular process Spinous process Superior articular process Bifid tip of spinous process Location of transverse foramen Inferior articular facet Vertebral body A lateral view of the same vertebra as in b.
7-7 Vertebral Regions The Cervical Vertebrae Transverse processes Are fused to costal processes Which encircle transverse foramina (protect arteries and veins) Atlas (C 1 ) Articulates with occipital condyles of skull Has no body or spinous process Has a large, round foramen within anterior and posterior arches
7-7 Vertebral Regions The Cervical Vertebrae Axis (C 2 ) Supports the atlas Has heavy spinous process To attach muscles of head and neck Axis and atlas bodies fuse during development to form the dens
Figure 7-19d The Cervical Vertebrae Anterior arch Transverse ligament Dens of axis Atlas (C 1 ) Posterior arch Axis (C 2 ) The atlas (C 1 ) and axis (C 2 ).
7-7 Vertebral Regions The Cervical Vertebrae Vertebra prominens (C 7 ) Transitions to thoracic vertebrae Has a long spinous process with a broad tubercle Has large transverse processes Ligamentum nuchae (elastic ligament) extends from C 7 to skull
7-7 Vertebral Regions Thoracic Vertebrae (T 1 T 12 ) Have heart-shaped bodies Larger bodies than in C 1 C 7 Smaller vertebral foramen than in C 1 C 7 Long, slender spinous processes Dorsolateral surfaces of body have costal facets Which articulate with heads of ribs
7-7 Vertebral Regions Thoracic Vertebrae (T 1 T 12 ) T 1 T 10 Have transverse costal facets On thick transverse processes for rib articulation Ribs at T 1 T 10 Contact costal and transverse costal facets T 1 T 8 articulate with two pairs of ribs At superior and inferior costal facets T 9 T 11 articulate with one pair of ribs T 10 T 12 transition to lumbar vertebrae
Figure 7-20a The Thoracic Vertebrae T 1 T 2 Intervertebral foramen T 4 T 3 T 5 T 6 Thoracic vertebrae (T 1 T 12 ) T 7 T 8 T 9 T 10 T 11 T 12 A lateral view of the thoracic region of the vertebral column. The vertebra prominems (C 7 ) resembles T 1, but lacks facets for rib articulation. Vertebra T 12 resembles the first lumbar vertebra (L 1 ) but has a facet for rib articulation.
Figure 7-20b The Thoracic Vertebrae Spinous process Transverse process Lamina Transverse costal facet Superior articular facet Vertebral foramen Superior costal facet Vertebral body Thoracic vertebra, superior view.
Figure 7-20c The Thoracic Vertebrae Spinous process Superior articular facet Transverse costal facet for tubercle of superior rib Transverse process Vertebral body Superior costal facet for head of superior rib Inferior costal facet for head of inferior rib Thoracic vertebra, lateral view.
7-7 Vertebral Regions Lumbar Vertebrae (L 1 L 5 ) Largest vertebrae Oval-shaped bodies Thicker bodies than T 1 T 12 No costal or transverse costal facets Triangular vertebral foramen Superior articular processes Face up and in Inferior articular processes Face down and out
7-7 Vertebral Regions Lumbar Vertebrae (L 1 L 5 ) Transverse processes Slender Project dorsolaterally Spinous process Short, heavy For attachment of lower back muscles
Figure 7-21a The Lumbar Vertebrae L 1 L 2 L 3 L 4 L 5 Sacrum Coccyx A lateral view of the lumbar vertebrae and sacrum
Figure 7-21b The Lumbar Vertebrae Superior articular process Pedicle Transverse process Spinous process Vertebral body Inferior articular facet Inferior articular process A lateral view of a typical lumbar vertebra
Figure 7-21c The Lumbar Vertebrae Spinous process Lamina Transverse process Superior articular facet Superior articular process Transverse process Vertebral foramen Pedicle Vertebral body A superior view of the same vertebra shown in part b
7-7 Vertebral Regions The Sacrum Is curved, more in males than in females Protects reproductive, urinary, and digestive organs Attaches: The axial skeleton to pelvic girdle of appendicular skeleton Broad muscles that move the thigh
7-7 Vertebral Regions The Sacrum The adult sacrum Consists of five fused sacral vertebrae Fuses between puberty and ages 25 30 Leaving transverse lines Sacral canal Replaces the vertebral canal
7-7 Vertebral Regions The Sacrum Sacral cornua Horn shaped Formed by laminae of the fifth sacral vertebra Which do not meet at midline Sacral hiatus Opening at the inferior end of the sacral canal Formed by ridges of sacral cornua Covered by connective tissues
7-7 Vertebral Regions The Sacrum Median sacral crest Fused spinous processes Four pairs of sacral foramina open to either side Lateral sacral crest Fused transverse processes Attach to muscles of lower back and hip
7-7 Vertebral Regions The Sacrum Auricular surface Thick, flattened area Articulates with pelvic girdle (forming sacroiliac joint) Sacral tuberosity Rough area Attaches ligaments of the sacroiliac joint
7-7 Vertebral Regions The Sacrum Base Ala The broad superior surface Wings at either side of the base To attach muscles Sacral promontory Apex At the center of the base The narrow inferior portion Articulates with the coccyx
7-7 Vertebral Regions The Coccyx Attaches ligaments and a constricting muscle of the anus Mature coccyx Consists of three to five fused coccygeal vertebrae First two coccygeal vertebrae Have transverse processes Have unfused vertebral arches Coccygeal cornua Formed by laminae of first coccygeal vertebra
Figure 7-22a The Sacrum and Coccyx Articular process Entrance to sacral canal Sacral tuberosity Lateral sacral crest Sacral hiatus Median sacral crest Sacral cornu Coccygeal cornu A posterior view
Figure 7-22b The Sacrum and Coccyx Sacral promontory Lateral sacral crest Auricular surface Median sacral crest Sacral cornu Coccygeal cornu Sacral curve Coccyx A lateral view from the right side
Figure 7-22c The Sacrum and Coccyx Base Sacral promontory Ala Ala Sacral foramina Transverse lines Apex Coccyx An anterior view
7-8 The Thoracic Cage The Thoracic Cage The skeleton of the chest Supports the thoracic cavity Consists of: Thoracic vertebrae Ribs Sternum (breastbone) The Rib Cage Formed of ribs and sternum
Figure 7-23a The Thoracic Cage Jugular notch T 1 Clavicular articulation 1 Manubrium 2 Sternum Body Xiphoid process Costal cartilages T 11 3 10 4 5 6 True ribs (ribs 1 7) Vertebrochondral ribs (ribs 8 10) Floating ribs (ribs 11 12) T 12 12 11 An anterior view, showing the costal cartilages and the sternum 7 8 9 False ribs (ribs 8 12)
Figure 7-23b The Thoracic Cage 3 4 5 6 2 1 C 7 T 1 T 2 T 3 T 4 T 5 T 6 1 2 3 4 5 6 True ribs (ribs 1 7) 7 T 7 7 8 T 8 8 9 10 11 12 T 9 T 10 T 11 T 12 L 1 12 11 9 10 False ribs (ribs 8 12) A posterior view, showing the articulations of the ribs and vertebrae
7-8 The Thoracic Cage Functions of the Thoracic Cage 1. Protects organs of the thoracic cavity Heart, lungs, and thymus 2. Attaches muscles 1. For respiration 2. Of the vertebral column 3. Of the pectoral girdle and the upper limbs
Figure 7-24c The Ribs Sternum Ribs The effect of rib movement on the thoracic cavity is similar to the movement of a bucket handle. Elevation of curved ribs increases the volume of the thoracic cavity.
7-8 The Thoracic Cage Ribs (Costae) Are 12 pairs of long, curved, flat bones Extending from the thoracic vertebrae Ribs are divided into two types 1. True ribs 2. False ribs
7-8 The Thoracic Cage Ribs 1 7 (True Ribs) Vertebrosternal ribs Connected to the sternum by costal cartilages
7-8 The Thoracic Cage Ribs 8 12 (False Ribs) Do not attach directly to the sternum Vertebrochondral ribs (ribs 8 10) Fuse together Merge with cartilage before reaching the sternum Floating or vertebral ribs (ribs 11 12) Connect only to the vertebrae and back muscles Have no connection with the sternum
Figure 7-23a The Thoracic Cage Jugular notch T 1 Clavicular articulation 1 Manubrium 2 Sternum Body Xiphoid process Costal cartilages T 11 3 10 4 5 6 True ribs (ribs 1 7) Vertebrochondral ribs (ribs 8 10) Floating ribs (ribs 11 12) T 12 12 11 An anterior view, showing the costal cartilages and the sternum 7 8 9 False ribs (ribs 8 12)
7-8 The Thoracic Cage Structures of the Ribs The head (capitulum) At the vertebral end of the rib Has superior and inferior articular facets The neck The short area between the head and the tubercle
7-8 The Thoracic Cage Structures of the Ribs The tubercle (tuberculum) A small dorsal elevation Has an auricular facet that contacts the facet of its thoracic vertebra (at T 1 T 10 only) The tubular body (shaft) Attaches muscles of the pectoral girdle and trunk Attaches to the intercostal muscles that move the ribs
Figure 7-24a The Ribs Transverse costal facet Tubercle of rib Angle Demifacet Neck Head (capitulum) Vertebral end A superior view of the details of rib structure and the articulations between the ribs and thoracic vertebrae.
Figure 7-24b The Ribs Attachment to costal cartilage (sternal end) Articular facets Tubercle Head Neck Body Angle Costal groove A posterior view of the head of a representative rib from the right side (ribs 2 9).
7-8 The Thoracic Cage The Sternum A flat bone In the midline of the thoracic wall Three parts of the sternum 1. The manubrium 2. The sternal body 3. The xiphoid process
7-8 The Thoracic Cage Manubrium The superior portion of sternum Broad, triangular shape Articulates with clavicles (collarbones) Articulates with cartilages of first rib pair Has a jugular notch, a shallow indentation between clavicular articulations
7-8 The Thoracic Cage The Sternal Body Is tongue-shaped Attaches to the manubrium Attaches to costal cartilages of ribs 2 7 The Xiphoid Process Is the smallest part of the sternum Attaches to the sternal body Attaches to diaphragm and rectus abdominis muscles
Figure 7-23a The Thoracic Cage Jugular notch T 1 Clavicular articulation 1 Manubrium 2 Sternum Body Xiphoid process Costal cartilages T 11 3 10 4 5 6 True ribs (ribs 1 7) Vertebrochondral ribs (ribs 8 10) Floating ribs (ribs 11 12) T 12 12 11 An anterior view, showing the costal cartilages and the sternum 7 8 9 False ribs (ribs 8 12)
7-8 The Thoracic Cage Development of the Sternum The developing sternal body Consists of four unfused bones Completes fusion about age 25 Leaving transverse lines The xiphoid process Is the last part of sternum to fuse Can easily be broken away