Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 7 The Axial Skeleton Lecture Presentation by Lee Ann Frederick University of Texas at Arlington © 2015 Pearson Education Inc. 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 © 2015 Pearson Education Inc. 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 © 2015 Pearson Education Inc. 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 © 2015 Pearson Education Inc. Figure 7-1a The Axial Skeleton. SKELETAL SYSTEM 206 AXIAL SKELETON APPENDICULAR SKELETON (see Figure 8-1) 8 Cranium 14 Face 6 Auditory ossicles Skull 1 Hyoid 1 Sternum 24 Ribs Associated bones Skull and 29 associated bones 25 Thoracic cage 26 Vertebral column 24 Vertebrae 1 Sacrum 1 Coccyx a 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. © 2015 Pearson Education, Inc. 80 Figure 7-1b The Axial Skeleton. Skull Cervical vertebrae Sternum Ribs Thoracic vertebrae Costal cartilages Lumbar vertebrae Sacrum Coccyx b Anterior (left) and posterior (right) views of the axial skeleton. The individual bones associated with the skull are not visible. © 2015 Pearson Education, Inc. 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 © 2015 Pearson Education Inc. 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 © 2015 Pearson Education Inc. Figure 7-2 Cranial and Facial Subdivisions of the Skull (Part 1 of 3). SKULL FACE 14 CRANIUM 8 Maxillae Palatine bones Nasal bones Inferior nasal conchae 2 2 1 Zygomatic bones Lacrimal bones Vomer Mandible 2 Occipital bone Parietal bones Frontal bone Temporal bones Sphenoid Ethmoid © 2015 Pearson Education, Inc. 2 2 2 1 1 2 1 ASSOCIATED BONES 7 Hyoid bone 1 6 2 1 1 Hyoid bone Auditory ossicles enclosed in temporal bones (detailed in Chapter 17) Figure 7-2 Cranial and Facial Subdivisions of the Skull (Part 2 of 3). Nasal bone Lacrimal bone Vomer Zygomatic bone Maxilla Mandible Facial bones protect and support the entrances to the digestive and respiratory tracts. © 2015 Pearson Education, Inc. Frontal bone Ethmoid Parietal bone Temporal bone Sphenoid Occipital bone Cranial bones surround and protect the brain. Figure 7-2 Cranial and Facial Subdivisions of the Skull (Part 3 of 3). Auditory ossicles © 2015 Pearson Education, Inc. 7-2 The Skull • Cranial Bones • Enclose the cranial cavity • Which contains the brain • And its fluids, blood vessels, nerves, and membranes © 2015 Pearson Education Inc. 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 © 2015 Pearson Education Inc. Figure 7-3a The Adult Skull. Major Sutures of the Skull Sagittal suture Parietal bone (left) Parietal bone (right) Lambdoid suture Occipital bone Squamous suture Temporal bone Mastoid process Styloid process Occipital condyle External occipital protuberance Mandible a Posterior view © 2015 Pearson Education, Inc. Figure 7-3b The Adult Skull. Occipital bone Major Sutures of the Skull Lambdoid suture Parietal bone (right) Parietal bone (left) Sagittal suture Coronal suture Frontal bone Zygomatic Bone Nasal bones b Superior view © 2015 Pearson Education, Inc. Figure 7-3c The Adult Skull. Major Sutures of the Skull Parietal bone Frontal bone Coronal suture Sphenoid Supraorbital foramen Squamous suture Temporal bone Nasal bone Lambdoid suture Lacrimal bone Squamous part of temporal bone External acoustic meatus Ethmoid Infraorbital foramen Occipital bone Maxilla Zygomatic bone Mastoid process Zygomatic arch Styloid process Zygomatic process of temporal bone Temporal process of zygomatic bone c © 2015 Pearson Education, Inc. Lateral view Mandible Mental foramen Mental protuberance Figure 7-3d The Adult Skull. Sagittal suture Foramen or Fissure Parietal bone Frontal Bone Coronal suture Supraorbital foramen Nasal bone Ethmoid Temporal bone Sphenoid Palatine bone Optic canal • Supraorbital nerve (branch of N V) • Supraorbital artery • Optic nerve (N II) • Ophthalmic artery Lacrimal bone Zygomatic bone Mastoid process of temporal bone Middle nasal concha (part of ethmoid) Superior orbital fissure • Oculomotor nerve (N III), trochlear nerve (N IV), opthalmic branch of trigeminal nerve (N V), and abducens nerve (N VI) Inferior orbital fissure • Maxillary branch of trigeminal nerve (N V) Maxilla Inferior nasal concha Infraorbital foramen Bony nasal septum • Infraorbital nerve, branch of maxillary nerve (N V) • Infraorbital artery Perpendicular plate of ethmoid Mandible Vomer Mental protuberance Major Structures Using Passageway d Anterior view Mental foramen • Mental nerve, branch of mandibular nerve (N V) • Mental vessels © 2015 Pearson Education, Inc. Figure 7-3e The Adult Skull. Frontal bone Sphenoid Maxilla Palatine bone Zygomatic bone Zygomatic arch Medial and lateral pterygoid processes Foramen lacerum (with temporal and occipital bones) • Internal carotid artery after leaving carotid canal Foramen ovale • Mandibular branch of trigeminal nerve (N V) • Auditory tube Temporal Bone Vomer External acoustic meatus • Air in meatus conducts sound to eardrum Occipital condyle Carotid canal • Internal carotid artery Mastoid process Stylomastoid foramen • Facial nerve (N V) Styloid process Mandibular fossa Occipital Bone Foramen magnum Lambdoid suture • Accessory nerve (XI) Occipital bone • Vertebral arteries External occipital protuberance e © 2015 Pearson Education, Inc. • Medulla oblongata (most caudal portion of brain) Inferior view Jugular foramen (with temporal bone) • Glossopharyngeal, vagus, and accessory nerves (N IX, X, XI) Figure 7-4 Sectional Anatomy of the Skull (Part 1 of 9). © 2015 Pearson Education, Inc. Figure 7-4 Sectional Anatomy of the Skull (Part 2 of 9). © 2015 Pearson Education, Inc. 7-2 The Skull • Superficial Facial Bones • Maxillae = maxillary bones • Lacrimal • Nasal • Zygomatic • Mandible • Deep Facial Bones • Palatine • Inferior nasal conchae • Vomer © 2015 Pearson Education Inc. 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 © 2015 Pearson Education Inc. 7-2 The Skull • Sutures • The immovable joints of the skull • The four major sutures 1. 2. 3. 4. © 2015 Pearson Education Inc. Lambdoid suture Coronal suture Sagittal suture 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 © 2015 Pearson Education Inc. 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 © 2015 Pearson Education Inc. 7-2 The Cranial Bones of the Skull • The Cranial Bones • Occipital bone • Parietal bones • Frontal bone • Temporal bones • Sphenoid • Ethmoid © 2015 Pearson Education Inc. 7-2 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) © 2015 Pearson Education Inc. 7-2 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 sites of muscles and ligaments © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-5a The Occipital and Parietal Bones. Hypoglossal canal Occipital condyle Foramen magnum External occipital crest Inferior nuchal line Superior nuchal line External occipital protuberance a Occipital bone, inferior view © 2015 Pearson Education, Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-5b The Occipital and Parietal Bones. Superior temporal line Inferior temporal line b © 2015 Pearson Education, Inc. Right parietal bone, lateral view 7-2 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 © 2015 Pearson Education Inc. • Lacrimal bone • Zygomatic bone • Spenoid • Nasal bone Figure 7-6a The Frontal Bone. Frontal (metopic) suture Frons Superior temporal line Glabella Supraorbital margin © 2015 Pearson Education, Inc. Supraorbital notch a Anterior surface Figure 7-6b The Frontal Bone. Supraorbital foramen Frontal Supraorbital margin sinus Lacrimal fossa b Inferior (orbital) surface © 2015 Pearson Education, Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 The Cranial Bones of the Skull • The Temporal Bones • Articulations of the temporal bones • Zygomatic bone • Sphenoid • Parietal bone • Occipital bone • Mandible © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-7a The Temporal Bones. Petrous part Squamous part (cerebral surface) Internal acoustic meatus Zygomatic process Mastoid process a Medial view of the Styloid process right temporal bone © 2015 Pearson Education, Inc. Figure 7-7b The Temporal Bones. Squamous part Mandibular fossa External acoustic meatus Styloid process Mastoid process b Lateral view of the right temporal bone © 2015 Pearson Education, Inc. Zygomatic process Figure 7-7bc The Temporal Bones. Squamous part Mandibular fossa External acoustic meatus External acoustic meatus Styloid process Mastoid process b Lateral view of the Mastoid process, cut to show mastoid cells right temporal bone c A cutaway view of the mastoid cells © 2015 Pearson Education, Inc. Zygomatic process 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-8a The Sphenoid. Foramen rotundum Optic Optic groove canal Foramen ovale Greater wing Foramen spinosum Sella turcica a © 2015 Pearson Education, Inc. Lesser wing Superior surface Sphenoidal spine Figure 7-8b The Sphenoid. Sphenoidal Superior sinus orbital fissure Greater wing Orbital surface Body Foramen rotundum Pterygoid process Pterygoid plates b Anterior surface © 2015 Pearson Education, Inc. Lesser wing 7-2 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) © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-9a The Ethmoid. Lateral mass containing ethmoidal labyrinth Olfactory foramina Cribriform plate Crista galli Perpendicular plate a © 2015 Pearson Education, Inc. Superior surface Figure 7-9b The Ethmoid. Crista galli Superior nasal concha Perpendicular plate b Posterior surface © 2015 Pearson Education, Inc. Middle nasal concha 7-2 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 © 2015 Pearson Education Inc. 7-2 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) © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-10a The Maxillae and Palatine Bones. Orbital rim Infraorbital foramen Alveolar process Zygomatic process a An anterolateral view of the right maxilla. © 2015 Pearson Education, Inc. Anterior nasal spine 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-10b The Maxillae and Palatine Bones. Palatine bone (horizontal plate) Palatine process Alveolar process Maxillary sinus b Superior view of a horizontal section through right maxilla and palatine bone; note the size and orientation of the maxillary sinus. © 2015 Pearson Education, Inc. 7-2 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) © 2015 Pearson Education Inc. 7-2 The Facial Bones of the Skull • The Nasal Bones • Articulations of the nasal bones • With other nasal bones • Ethmoid • Frontal bones • Maxillae © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 The Facial Bones of the Skull • The Inferior Nasal Conchae • Articulations of the inferior nasal conchae • Ethmoid • Maxillae • Palatine bones • Lacrimal bones © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-11 The Smaller Bones of the Face (Part 1 of 2). Supraorbital foramen Nasal bone Sphenoid Temporal bone Zygomaticofacial foramen Zygomatic bone Infraorbital foramen Maxilla Perpendicular plate of ethmoid Vomer Bony nasal septum © 2015 Pearson Education, Inc. Figure 7-11 The Smaller Bones of the Face (Part 2 of 2). 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 © 2015 Pearson Education, Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. 7-2 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 © 2015 Pearson Education Inc. Figure 7-12a The Mandible. Articular surface for temporomandibular joint Coronoid process Teeth Mandibular notch Head Ramus Condylar process Body Mental protuberance Mental foramen Angle a A lateral and slightly superior view of the mandible © 2015 Pearson Education, Inc. Figure 7-12b The Mandible. Alveolar process Articular surface Condylar process Coronoid process Mandibular foramen Mylohyoid line Depression for submandibular salivary gland b A medial view of the right mandible © 2015 Pearson Education, Inc. Figure 7-13 An Anterior View of the Hyoid Bone. Greater horn Lesser horn Body An anterior view of the hyoid bone © 2015 Pearson Education, Inc. 7-3 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 © 2015 Pearson Education Inc. Figure 7-14 The Orbital Complex (Part 1 of 2). Frontal bone Supraorbital notch Sphenoid Optic canal Ethmoid Superior orbital fissure Lacrimal bone Lacrimal sulcus Nasolacrimal canal Palatine bone Interior orbital fissure Zygomatic bone Infraorbital groove © 2015 Pearson Education, Inc. Infraorbital foramen Maxilla Figure 7-14 The Orbital Complex (Part 2 of 2). Supraorbital notch Frontal bone Sphenoid Optic canal Superior orbital fissure Ethmoid Nasolacrimal canal Inferior orbital fissure Infraorbital groove Zygomatic bone Maxilla © 2015 Pearson Education, Inc. Infraorbital foramen Figure 7-15a The Nasal Complex. Frontal sinus Ethmoid air cells Sphenoidal sinus Maxillary sinus a Locations of the paranasal sinuses. © 2015 Pearson Education, Inc. Figure 7-15b The Nasal Complex. Frontal bone Sphenoidal sinuses Frontal sinuses Sphenoid Ethmoid Nasal bone Nasal conchae of ethmoid Palatine bone (bony palate) Superior Maxilla (bony palate) Middle Inferior nasal concha b A sagittal section through the skull, with the nasal septum removed to show major features of the wall of the right nasal cavity. The frontal and sphenoidal sinuses are visible. © 2015 Pearson Education, Inc. 7-3 The Orbital and Nasal Complexes • Paranasal Sinuses • Air-filled chambers connected to the nasal cavities • Lighten skull bones • Provide mucous epithelium (flushes nasal cavities) © 2015 Pearson Education Inc. 7-4 Fontanelles • The Infant Skull • Grows rapidly • Is large compared to the body • Has many ossification centers © 2015 Pearson Education Inc. 7-4 Fontanelles • The Infant Skull • Fusion is not complete at birth • Two frontal bones • Four occipital bones • Several sphenoidal and temporal elements © 2015 Pearson Education Inc. 7-4 Fontanelles • Fontanelles • Are areas of fibrous connective tissue (soft spots) • Cover unfused sutures in the infant skull • Allow the skull to flex during birth © 2015 Pearson Education Inc. 7-4 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 © 2015 Pearson Education Inc. Figure 7-16a The Skull of an Infant. Fontanelles Sphenoidal Mastoid fontanelle fontanelle Coronal suture Parietal bone Frontal bone Greater wing of sphenoid Nasal bone Maxilla Mandible Temporal Squamous Occipital Lambdoid bone suture suture bone a © 2015 Pearson Education, Inc. Lateral view Figure 7-16b The Skull of an Infant. Fontanelles Anterior fontanelle Posterior fontanelle Coronal suture Parietal bone Frontal bone Sagittal suture Frontal suture Frontal bone Parietal bone Lambdoid suture Coronal suture b © 2015 Pearson Education, Inc. Occipital bone Superior view 7-5 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 © 2015 Pearson Education Inc. Figure 7-17 The Vertebral Column. Spinal Curves Vertebral Regions Primary curves develop before birth, and secondary curves after birth. Regions are defined by anatomical characteristics of individual vertebrae. The cervical curve, a secondary curve, develops as the infant learns to balance the weight of the head on the vertebrae of the neck. The thoracic curve, a primary curve, accommodates the thoracic organs. C1 C2 C3 C4 C5 C6 C7 T1 T2 T3 T4 T5 T6 T7 Cervical (7 vertebrae) Thoracic (12 vertebrae) T8 T9 T10 T11 T12 L1 The lumbar curve, a secondary curve, balances the weight of the trunk over the lower limbs; it develops with the ability to stand. L2 L3 Lumbar (5 vertebrae) L4 L5 The sacral curve, a primary curve, accommodates the abdominopelvic organs. © 2015 Pearson Education, Inc. Sacral Coccygeal 7-5 The Vertebral Column • Four Spinal Curves 1. 2. 3. 4. Cervical curve Thoracic curve Lumbar curve Sacral curve © 2015 Pearson Education Inc. 7-5 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) © 2015 Pearson Education Inc. Clinical Note 7-2a Kyphosis, Lordosis, and Scoliosis. a Kyphosis © 2015 Pearson Education, Inc. Clinical Note 7-2b Kyphosis, Lordosis, and Scoliosis. b Lordosis © 2015 Pearson Education, Inc. Clinical Note 7-2c Kyphosis, Lordosis, and Scoliosis. c Scoliosis © 2015 Pearson Education, Inc. Figure 7-18a Vertebral Anatomy. Vertebral arch Articular processes Pedicle Vertebral body a The major components of a typical vertebra © 2015 Pearson Education, Inc. Figure 7-18b Vertebral Anatomy. Superior articular process Pedicle Transverse process Vertebral body Spinous process Inferior articular facet Inferior articular process Arrow passing through vertebral foramen b A lateral and slightly inferior view of a vertebra © 2015 Pearson Education, Inc. Figure 7-18c Vertebral Anatomy. Spinous process Superior articular process Transverse process Inferior articular process Pedicle Inferior articular facet Vertebral foramen Vertebral body c An inferior view of a vertebra © 2015 Pearson Education, Inc. 7-5 The Vertebral Column • Intervertebral Discs • Are pads of fibrocartilage • Separate the vertebral bodies • Absorb shocks © 2015 Pearson Education Inc. Figure 7-18d Vertebral Anatomy. Superior articular facets Superior articular process Lamina of vertebral arch Spinous process Intervertebral disc Transverse process Vertebral body d A posterior view of © 2015 Pearson Education, Inc. 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 e A lateral and sectional view of © 2015 Pearson Education, Inc. three articulated vertebrae 7-6 Vertebral Regions • Regions of the Vertebral Column • Cervical (C) • Thoracic (T) • Lumbar (L) • Sacral (S) • Coccygeal (Co) © 2015 Pearson Education Inc. 7-6 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 • C1 (atlas) has no spinous process • All others have short spinous processes • Tip of each spinous process is notched (bifid) © 2015 Pearson Education Inc. Figure 7-19a The Cervical Vertebrae. C1 C2 C3 C4 C5 Spinous process of vertebra prominens C6 C7 a A lateral view of the cervical vertebrae, C1–C7. © 2015 Pearson Education, Inc. Figure 7-19b The Cervical Vertebrae. Vertebral arch Spinous process Lamina Vertebral foramen Superior articular process Pedicle Vertebral body Transverse process Costal process Superior Transverse articular facet foramen b A superior view of a representative cervical vertebra showing characteristics of C3–C6. Notice the typical features listed in Table 7–1. © 2015 Pearson Education, Inc. 7-6 Vertebral Regions • The Cervical Vertebrae • Transverse processes • Are fused to costal processes • Which encircle transverse foramina (protect arteries and veins) • Atlas (C1) • Articulates with occipital condyles of skull • Has no body or spinous process • Has a large, round foramen within anterior and posterior arches © 2015 Pearson Education Inc. 7-6 Vertebral Regions • The Cervical Vertebrae • Axis (C2) • 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 © 2015 Pearson Education Inc. Figure 7-19d The Cervical Vertebrae. Anterior arch Dens of axis Transverse ligament Atlas (C1) Posterior arch Axis (C2) d The atlas (C1) and axis (C2) in posterolateral view. © 2015 Pearson Education, Inc. Figure 7-20a The Thoracic Vertebrae. Vertebra prominens C7 T1 T2 Intervertebral foramen T3 T4 T5 T6 T7 Thoracic vertebrae (T1–T12) T8 T9 T10 T11 T12 L1 a © 2015 Pearson Education, Inc. A lateral view of the thoracic region of the vertebral column. The vertebra prominens (C7) resembles T1, but lacks facets for rib articulation. Vertebra T12 resembles the first lumbar vertebra (L1) but has a fact 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 b Thoracic vertebra, superior view. © 2015 Pearson Education, Inc. Figure 7-20c The Thoracic Vertebrae. Transverse costal facet for tubercle of superior rib Transverse process Superior costal facet for head of superior rib Vertebral body Spinous process Inferior costal facet for head of inferior rib c Thoracic vertebra, lateral view. © 2015 Pearson Education, Inc. Figure 7-21a The Lumbar Vertebrae. L1 L2 L3 L4 L5 Sacrum Coccyx a © 2015 Pearson Education, Inc. A lateral view of the lumbar vertebrae, sacrum, and coccyx Figure 7-21b The Lumbar Vertebrae. Superior articular process Pedicle Transverse process Spinous process Vertebral body Inferior articular process Inferior articular facet b © 2015 Pearson Education, Inc. A lateral view of a typical lumbar vertebra Figure 7-21c The Lumbar Vertebrae. Spinous process Superior articular facet Lamina Superior articular process Transverse process Transverse process Vertebral foramen Pedicle Vertebral body c © 2015 Pearson Education, Inc. A superior view of the same vertebra shown in part b Table 7-1 Regional Differences in Vertebral Structure and Function (Part 2 of 2). © 2015 Pearson Education, Inc. 7-6 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 © 2015 Pearson Education Inc. 7-6 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 © 2015 Pearson Education Inc. Figure 7-22a The Sacrum and Coccyx. Articular Entrance to process sacral canal Sacral tuberosity Lateral sacral crest Median sacral crest Sacral hiatus Sacral cornu Coccygeal cornu © 2015 Pearson Education, Inc. a A posterior view Figure 7-22b The Sacrum and Coccyx. Sacral promontory Auricular surface Lateral sacral crest Median sacral crest Sacral curve Sacral cornu Coccygeal cornu Coccyx b © 2015 Pearson Education, Inc. 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 c © 2015 Pearson Education, Inc. An anterior view 7-7 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 © 2015 Pearson Education Inc. Figure 7-23a The Thoracic Cage. Jugular notch T1 Clavicular articulation 1 Sternum 2 Manubrium 3 Body Xiphoid process Costal cartilages 5 10 T11 T12 Vertebrochondral ribs (ribs 8–10) True ribs (ribs 1–7) 4 11 12 6 7 8 9 Floating ribs (ribs 11–12) a An anterior view, showing the costal cartilages and the sternum © 2015 Pearson Education, Inc. False ribs (ribs 8–12) Figure 7-23b The Thoracic Cage. 1 2 3 4 5 True ribs (ribs 1–7) T4 T5 2 3 4 6 T7 6 7 T8 8 T9 7 8 T10 11 © 2015 Pearson Education, Inc. T3 1 5 10 12 b T2 T6 9 False ribs (ribs 8–12) C7 T1 T11 9 T12 10 L1 11 12 A posterior view, showing the articulations of the ribs and vertebrae 7-7 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 © 2015 Pearson Education Inc. 7-7 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 © 2015 Pearson Education Inc. 7-7 The Thoracic Cage • Ribs 1–7 (True Ribs) • Vertebrosternal ribs • Connected to the sternum by costal cartilages © 2015 Pearson Education Inc. 7-7 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 © 2015 Pearson Education Inc. 7-7 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 © 2015 Pearson Education Inc. Figure 7-24a The Ribs. Transverse costal facet Tubercle of rib Angle Neck Demifacet Head (capitulum) Vertebral end a A superior view of the details of rib structure and the articulations between the ribs and thoracic vertebrae © 2015 Pearson Education, Inc. Figure 7-24b The Ribs. Head Neck Attachment to costal cartilage (sternal end) Articular facets Tubercle Body Angle b A posterior view of the head of a Costal groove representative rib from the right side (ribs 2–9) © 2015 Pearson Education, Inc. 7-7 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 © 2015 Pearson Education Inc. 7-7 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 © 2015 Pearson Education Inc. 7-7 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 © 2015 Pearson Education Inc. 7-7 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 © 2015 Pearson Education Inc.