Overview of the Skeleton two regions of the

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Overview of the Skeleton • two regions of the skeleton – axial skeleton –

Overview of the Skeleton • two regions of the skeleton – axial skeleton – forms the central supporting axis of the body • skull, auditory ossicles, hyoid bone, vertebral column, and thoracic cage (ribs and sternum) – appendicular skeleton – includes the bones of the upper limb and pectoral girdle, and the bones of the lower limb and pelvic girdle • number of bones – 206 in typical adult skeleton • varies with development of sesamoid bones (patella) – bones that form within some tendons in response to stress • varies with presence of sutural (wormian) bones in skull – extra bones that develop in skull suture lines – 270 bones at birth, decreases with fusion • surface markings – ridges, spines, bumps, depressions, canals, pores, slits, cavities, 8 -1 and articular surfaces

The Skeletal System Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

The Skeletal System Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Parietal bone Frontal bone • overview of the skeleton Skull • the vertebral column and thoracic cage Mandible Pectoral girdle • the skull Maxilla Clavicle Scapula Sternum Thoracic cage Humerus Ribs Costal cartilages Vertebral column Pelvis Hip bone Sacrum Ulna Radius Coccyx Carpus Metacarpal bones Phalanges • the pectoral girdle and upper limb Femur Patella Fibula • the pelvic girdle and lower limb Tibia Metatarsal bones Tarsus Phalanges (a) Anterior view Figure 8. 1 a 8 -2

Axial and Appendicular Skeleton Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Axial and Appendicular Skeleton Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Parietal bone Frontal bone Skull Pectoral girdle Occipital bone Maxilla Mandible Clavicle Scapula • axial skeleton is colored tan – skull, vertebrae, sternum, ribs, sacrum and hyoid Sternum Humerus Thoracic Ribs cage Costal cartilages Vertebral column Pelvis Hip bone Sacrum • appendicular skeleton is colored green Ulna Radius Coccyx Carpus Metacarpal bones Phalanges – – Femur Patella Fibula Tibia pectoral girdle upper extremity pelvic girdle lower extremity Metatarsal bones Tarsus Figure 8. 1 Phalanges (a) Anterior view (b) Posterior view 8 -3

The Skull • skull – the most complex part of the skeleton • 22

The Skull • skull – the most complex part of the skeleton • 22 bones joined together by sutures (immovable joints) • 8 cranial bones surround cranial cavity which encloses the brain • other cavities – orbits, nasal cavity, oral (buccal) cavity, middle-, and inner ear cavities, and paranasal sinuses • paranasal sinuses – frontal, sphenoid, ethmoid, and maxillary – lined by mucous membrane and air-filled – lighten the anterior portion of the skull – act as chambers that add resonance to the voice • foramina – holes that allow passage for nerves and blood vessels • 14 facial bones support teeth, facial and jaw muscles 8 -4

Major Skull Cavities Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Major Skull Cavities Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Cranial cavity Ethmoid air cells Frontal bone Ethmoid bone Orbit Superior Nasal conchae Middle Zygomatic bone Inferior Maxillary sinus Vomer Nasal cavity Mandible Oral cavity Figure 8. 7 8 -5

Frontal Bone • forms forehead and part of the roof of the cranium •

Frontal Bone • forms forehead and part of the roof of the cranium • coronal suture – posterior boundary of frontal bone • supraorbital margin forms roof of the orbit • supraorbital foramen provides passage for nerve, artery, and vein • glabella – smooth area above root of the nose • contains frontal sinus Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Frontal bone Glabella Coronal suture Squamous suture Supraorbital foramen Parietal bone Supraorbital margin Temporal bone Sphenoid bone Lacrimal bone Ethmoid bone Nasal bone Middle nasal concha Zygomatic bone Infraorbital foramen Vomer Inferior nasal concha Maxilla Mandible Mental protuberance Mental foramen Figure 8. 3 8 -6

Parietal Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Parietal Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone Temporal lines Lambdoid suture Ethmoid bone Sphenoid bone Nasal bone Occipital bone Lacrimal bone Squamous suture • form most of cranial roof and part of its lateral walls Zygomaticofacial foramen Temporal bone Infraorbital foramen Zygomatic process External acoustic meatus Zygomatic bone Maxilla Mastoid process Temporal process Styloid process Mandible Mandibular condyle Mental foramen (a) Right lateral view Figure 8. 4 a Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Anterior Frontal bone Coronal suture Parietal bone Sagittal suture • bordered by 4 sutures – sagittal – between parietal bones – coronal – at anterior margin – lambdoid – at posterior margin – squamous – at lateral border Sutural bone Parietal foramen Lambdoid suture Occipital bone Posterior Figure 8. 6 8 -7

Temporal Bone • lateral wall and part of floor of cranial cavity – squamous

Temporal Bone • lateral wall and part of floor of cranial cavity – squamous part Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone Temporal lines Lambdoid suture Ethmoid bone Sphenoid bone Nasal bone Occipital bone Lacrimal bone Squamous suture Zygomaticofacial foramen Temporal bone Infraorbital foramen Zygomatic process External acoustic meatus Zygomatic bone – tympanic part • external auditory meatus • styloid process Maxilla Mastoid process Temporal process Styloid process Mandible Mandibular condyle Mental foramen (a) Right lateral view Figure 8. 4 a • encircled by squamous suture • zygomatic process • mandibular fossa – mastoid part • mastoid process – mastoiditis from ear infection • mastoid notch • stylomastoid foramen • mastoid foramen 8 -8

Right Temporal Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Right Temporal Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Squamous suture Squamous part Mastoid part Zygomatic process Mandibular fossa Mastoid notch Mastoid process Styloid process External acoustic meatus Tympanic part (a) Lateral surface Squamous suture Squamous part Petrous part Zygomatic process Internal acoustic meatus Mastoid process Styloid process (b) Medial surface Figure 8. 10 8 -9

Petrous Portion of Temporal Bone – petrous part • part of cranial floor Copyright

Petrous Portion of Temporal Bone – petrous part • part of cranial floor Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Diploe (spongy bone) Frontal bone Crista galli Cribriform plate of ethmoid bone Cribriform foramina • separates middle from posterior cranial fossa Sphenoid bone Optic foramen Sella turcica Foramen rotundum Foramen ovale Temporal bone Foramen spinosum Internal acoustic meatus • houses middle and inner ear cavities Petrous part of temporal bone Jugular foramen Parietal bone Groove for venous sinus Foramen magnum Occipital bone Hypoglossal canal (b) Superior view of cranial floor Figure 8. 5 b • receptors for hearing and sense of balance • internal auditory meatus - opening for CN VII (vestibulocochlear nerve) • carotid canal • jugular foramen 8 -10

Occipital Bone • rear and base of skull • foramen magnum holds spinal cord

Occipital Bone • rear and base of skull • foramen magnum holds spinal cord • basilar part Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Incisive foramen Palatine process of maxilla Intermaxillary suture Zygomatic bone Palatine bone Zygomatic arch Greater palatine foramen • skull rests on atlas at occipital condyles Posterior nasal aperture Medial pterygoid plate Lateral pterygoid plate Vomer Sphenoid bone Foramen ovale Mandibular fossa Foramen spinosum Foramen lacerum Basilar part of occipital bone Carotid canal Styloid process • hypoglossal canal transmits hypoglossal nerve (CN XII) supplying tongue muscles External acoustic meatus Occipital condyle Stylomastoid foramen Mastoid process Mastoid notch Temporal bone Jugular foramen Foramen magnum Condylar canal Mastoid foramen Parietal bone Lambdoid suture Inferior nuchal line • condylar canal • external occipital protuberance for nuchal ligament • superior and inferior nuchal lines mark neck muscles External occipital protuberance Superior nuchal line Occipital bone (a) Inferior view Figure 8. 5 a 8 -11

Sphenoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Sphenoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Lesser wing Dorsum sellae Greater wing Superior orbital fissure Foramen rotundum Body Foramen ovale Lateral pterygoid plate Medial pterygoid plate Pterygoid processes (b) Posterior view Figure 8. 11 b Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Diploe (spongy bone) Frontal bone Cribriform plate of ethmoid bone Crista galli Cribriform foramina Sphenoid bone Optic foramen Foramen rotundum Foramen ovale Foramen spinosum Internal acoustic meatus Jugular foramen Sella turcica Temporal bone Petrous part of temporal bone Parietal bone Foramen magnum Groove for venous sinus Hypoglossal canal • body • greater wing • lesser wing • optic foramen • anterior clinoid processes • superior orbital fissure Occipital bone (b) Superior view of cranial floor Figure 8. 5 b 8 -12

Sphenoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Sphenoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Optic foramen Hypophyseal fossa Lesser wing Greater wing Foramen rotundum Sella turcica Anterior clinoid process Foramen ovale Foramen spinosum Dorsum sellae (a) Superior view Figure 8. 11 a Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Diploe (spongy bone) Frontal bone Cribriform plate of ethmoid bone Crista galli Cribriform foramina Sphenoid bone Optic foramen Foramen rotundum Foramen ovale Foramen spinosum Internal acoustic meatus Jugular foramen Sella turcica Temporal bone Petrous part of temporal bone Parietal bone Foramen magnum Groove for venous sinus Hypoglossal canal Occipital bone Figure 8. 5 b (b) Superior view of cranial floor • foramen rotundum • foramen ovale • foramen lacerum • posterior nasal apertures or choanae • medial pterygoid plate • lateral pterygoid plate • sphenoid sinus 8 -13

Sphenoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Sphenoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Incisive foramen Parietal bone Palatine process of maxilla Sphenoid sinus Squamous suture Frontal sinus Intermaxillary suture Zygomatic bone Crista galli Palatine bone Zygomatic arch Cribriform plate of ethmoid bone Posterior nasal aperture Perpendicular plate of ethmoid bone Vomer Occipital bone Temporal bone Sella turcica Lambdoid suture Internal acoustic meatus Jugular foramen Hypoglossal canal Styloid process Mandibular foramen Medial pterygoid plate Lateral pterygoid plate Nasal bone Sphenoid bone Foramen ovale Vomer Mandibular fossa Palatine process of maxilla Styloid process Foramen spinosum Foramen lacerum Basilar part of occipital bone Carotid canal Maxilla (b) Median section Greater palatine foramen External acoustic meatus Occipital condyle Stylomastoid foramen Palatine bone Mandible Mastoid process Mastoid notch Mental spines Temporal bone Jugular foramen Foramen magnum Condylar canal Mastoid foramen Parietal bone Lambdoid suture Inferior nuchal line Figure 8. 4 b External occipital protuberance Superior nuchal line Occipital bone (a) Inferior view Figure 8. 5 a sphenoid sinus 8 -14

Ethmoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Ethmoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Supraorbital foramen Roof of orbit Lesser wing of sphenoid bone Zygomatic process of frontal bone Greater wing of sphenoid bone Orbital plate of ethmoid bone Floor of orbit between the eyes • contributes to medial wall of orbit • lateral walls and roof of nasal cavity, and nasal septum • three major portions of this porous, delicate bone • perpendicular plate forms superior two-thirds of nasal septum • cribriform plate – forms roof of nasal cavity – crista galli – attachment point for meninges – cribriform (olfactory) foramina • labyrinth – large mass on each side of perpendicular plate – ethmoid cells in the make up ethmoid sinuses 8 -15 – orbital plate Orbital plate of frontal bone Optic foramen Medial wall • Lacrimal bone Lateral wall of orbit Orbital surface of zygomatic bone Superior orbital fissure Frontal process of maxilla Orbital process of palatine bone Inferior orbital fissure Infraorbital foramen Orbital surface of maxilla Figure 8. 14 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Cribriform plate Cribriform foramina Orbital plate Ethmoidal cells Perpendicular plate Figure 8. 12 Crista galli Superior nasal concha Middle nasal concha

Ethmoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Ethmoid Bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone Crista galli Cribriform plate Sphenoid sinus Cribriform foramina Squamous suture Frontal sinus Nasal bone Sella turcica Crista galli Nasal conchae: Occipital bone Temporal bone Sella turcica Lambdoid suture Internal acoustic meatus Jugular foramen Hypoglossal canal Frontal bone Cribriform plate of ethmoid bone Superior Perpendicular plate Sphenoid sinus of ethmoid bone Inferior Nasal bone Middle Nasal cartilages Occipital bone Vomer Palatine process of maxilla Styloid process Mandibular foramen Maxilla Palatine bone Mandible Mental spines (b) Median section Sphenoid bone Anterior nasal spine Palatine bone Incisive foramen Lacrimal bone Lip Maxilla Incisor Figure 8. 4 b Figure 8. 13 superior and middle concha perpendicular plate of nasal septum 8 -16

Facial Bones • facial bones (14)– those that have no direct contact with the

Facial Bones • facial bones (14)– those that have no direct contact with the brain or meninges – – support the teeth give shape and individuality to the face form part of the orbital and nasal cavities provide attachments for muscles of facial expression and mastication 2 maxillae 2 palatine bones 2 zygomatic bones 2 lacrimal bones 2 nasal bones 2 inferior nasal conchae 1 vomer 1 mandible 8 -17

Maxillary Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Maxillary Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Frontal bone • largest facial bones • forms upper jaw and meet each other at a median intermaxillary suture – alveolar processes are bony points between teeth – alveolus - sockets that hold teeth • forms inferomedial wall of orbit – infraorbital foramen – inferior orbital fissure • forms most of the hard palate – palatine process – palate – forms the roof of the mouth and floor of nasal cavity – incisive foramen – palate allows us to chew while breathing – cleft palate and cleft lip Supraorbital foramen Glabella Parietal bone Coronal suture Supraorbital margin Squamous suture Temporal bone Sphenoid bone Lacrimal bone Ethmoid bone Nasal bone Middle nasal concha Zygomatic bone Inferior nasal concha Infraorbital foramen Maxilla Vomer Figure 8. 3 Mandible Mental foramen Mental protuberance Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Incisive foramen Palatine process of maxilla Zygomatic bone Intermaxillary suture Zygomatic arch Palatine bone Greater palatine foramen Medial pterygoid plate Lateral pterygoid plate Posterior nasal aperture Vomer Sphenoid bone Mandibular fossa Foramen ovale Foramen spinosum Foramen lacerum Basilar part of occipital bone Carotid canal Stylomastoid foramen Jugular foramen Foramen magnum Mastoid foramen Styloid process External acoustic meatus Occipital condyle Mastoid process Mastoid notch Temporal bone Condylar canal Parietal bone Lambdoid suture Inferior nuchal line External occipital protuberance Superior nuchal line Occipital bone Figure 8. 5 a (a) Inferior view 8 -18

Location of Maxillary Sinus Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Location of Maxillary Sinus Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Sphenoid sinus Frontal sinus Ethmoid sinus Maxillary sinus Figure 8. 8 • maxillary sinus fills maxillae bone • larger in volume than frontal, sphenoid and ethmoid sinuses 8 -19

Palatine Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Palatine Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • L-shaped bone Crista galli Frontal bone Cribriform plate • form the posterior portion of the hard palate Frontal sinus Cribriform foramina Nasal bone Sella turcica Nasal conchae: Superior Middle Sphenoid sinus Inferior Nasal cartilages Occipital bone • part of lateral nasal cavity wall Sphenoid bone • part of the orbital floor • greater palatine foramina Roof of orbit Anterior nasal spine Palatine bone Incisive foramen Lacrimal bone Lip Maxilla Incisor Figure 8. 13 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Supraorbital foramen Orbital plate of frontal bone Lesser wing of sphenoid bone Zygomatic process of frontal bone Greater wing of sphenoid bone Optic foramen Orbital surface of zygomatic bone Orbital plate of ethmoid bone Medial wall Floor of orbit Lateral wall of orbit Lacrimal bone Superior orbital fissure Frontal process of maxilla Inferior orbital fissure Orbital process of palatine bone Infraorbital foramen Orbital surface of maxilla Figure 8. 14 8 -20

Zygomatic Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Zygomatic Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone Temporal lines Lambdoid suture Ethmoid bone Sphenoid bone Nasal bone Occipital bone Lacrimal bone Squamous suture Zygomaticofacial foramen Temporal bone • forms angles of the cheekbones and part of lateral orbital wall • zygomaticofacial foramen Infraorbital foramen Zygomatic process External acoustic meatus Zygomatic bone Maxilla Mastoid process Temporal process Styloid process Mandible Mandibular condyle Mental foramen (a) Right lateral view Figure 8. 4 a • zygomatic arch is formed from temporal process of zygomatic bone and zygomatic process of temporal bone 8 -21

Lacrimal Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Lacrimal Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone Temporal lines Lambdoid suture Ethmoid bone Sphenoid bone Nasal bone Occipital bone • form part of medial wall of each orbit • smallest bone of skull Lacrimal bone Squamous suture Zygomaticofacial foramen Temporal bone Infraorbital foramen Zygomatic process External acoustic meatus Zygomatic bone Maxilla Mastoid process Temporal process Styloid process Mandible Mandibular condyle Mental foramen (a) Right lateral view • lacrimal fossa houses lacrimal sac in life – tears collect in lacrimal sac and drain into nasal cavity Figure 8. 4 a 8 -22

Nasal Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Nasal Bones Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • forms bridge of nose Frontal bone Glabella Coronal suture • supports cartilages that shape lower portion of the nose • often fractured by blow to the nose Squamous suture Supraorbital foramen Parietal bone Supraorbital margin Temporal bone Sphenoid bone Lacrimal bone Ethmoid bone Nasal bone Middle nasal concha Zygomatic bone Infraorbital foramen Vomer Inferior nasal concha Maxilla Mandible Mental protuberance Mental foramen Figure 8. 3 8 -23

Inferior Nasal Conchae • three conchae in the nasal cavity – superior and middle

Inferior Nasal Conchae • three conchae in the nasal cavity – superior and middle are part of the ethmoid bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Crista galli Frontal bone Cribriform plate Frontal sinus Cribriform foramina Nasal bone Sella turcica Nasal conchae: Superior Middle Sphenoid sinus Inferior Nasal cartilages Occipital bone Sphenoid bone Anterior nasal spine • inferior nasal concha is a separate bone Palatine bone Incisive foramen Lacrimal bone Lip Maxilla Incisor Figure 8. 13 • largest of the three 8 -24

Vomer Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Vomer Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone Sphenoid sinus Squamous suture Frontal sinus Crista galli Occipital bone Cribriform plate of ethmoid bone Temporal bone Sella turcica Lambdoid suture Internal acoustic meatus Jugular foramen Hypoglossal canal Perpendicular plate of ethmoid bone Nasal bone Vomer Palatine process of maxilla Styloid process Mandibular foramen • inferior half of the nasal septum – superior half formed by perpendicular plate of ethmoid Maxilla Palatine bone Mandible Mental spines (b) Median section Figure 8. 4 b • supports cartilage that forms the anterior part of the nasal septum 8 -25

Mandible Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Mandible Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • • strongest bone of the skull only bone of skull that moves noticeably supports lower teeth provides attachments for muscles of facial expression and mastication mental symphysis – median cartilaginous joint in fetus – develops as two separate bones in fetus – ossifies in early childhood mental protuberance – point of chin two major parts on each side – body – supports teeth – ramus – articulates with cranium • angle – where body and ramus meet alveolar processes between teeth mental foramen Figure mental spines Figure 8. 5 a Incisive foramen Palatine process of maxilla Intermaxillary suture Zygomatic bone Palatine bone Zygomatic arch Greater palatine foramen Posterior nasal aperture Medial pterygoid plate Lateral pterygoid plate Vomer • Sphenoid bone Foramen ovale Mandibular fossa Foramen spinosum Foramen lacerum Basilar part of occipital bone Carotid canal Styloid process External acoustic meatus Occipital condyle Stylomastoid foramen Mastoid process Mastoid notch Temporal bone Jugular foramen Foramen magnum Condylar canal Mastoid foramen Parietal bone Lambdoid suture Inferior nuchal line External occipital protuberance Superior nuchal line • • Occipital bone (a) Inferior view Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Mandibular condyles Condylar process Coronoid process Mandibular notch Mandibular foramen Ramus Alveolar process • • • Mental foramen Mental protuberance 8. 15 Angle Body 8 -26

Ramus, Angle and Body of Mandible Copyright © The Mc. Graw-Hill Companies, Inc. Permission

Ramus, Angle and Body of Mandible Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Mandibular condyles Condylar process Coronoid process Mandibular notch Mandibular foramen Ramus Alveolar process Mental foramen Mental protuberance Angle Body • condylar process bears the mandibular condyle – oval knob that articulates with the mandibular fossa of the temporal bone forming the hinge temporomandibular joint (TMJ) • coronoid process – point of insertion of temporalis muscle • mandibular notch Figure 8. 15 • mandibular foramen 8 -27

Bones Associated With Skull • auditory ossicles – three in each middle-ear cavity –

Bones Associated With Skull • auditory ossicles – three in each middle-ear cavity – malleus, incus, and stapes Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • hyoid bone – slender u-shaped bone between the chin and larynx – does not articulate with any other bone – suspended from styloid process of skull by muscle and ligament – body and greater and lesser horns (cornua) – fractured hyoid bone is evidence of strangulation Styloid process Stylohyoid muscle Hyoid Larynx Lesser horn Greater horn Body Figure 8. 16 8 -28

Skull in Infancy and Childhood Copyright © The Mc. Graw-Hill Companies, Inc. Permission required

Skull in Infancy and Childhood Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone – filled with fibrous membrane – allow shifting of bones during birth and growth of brain – anterior, posterior, sphenoid (anterolateral), and mastoid (posterolateral fontanels Sphenoid fontanel Lambdoid suture Nasal bone Squamous suture Maxilla Occipital bone Zygomatic bone Mastoid fontanel Temporal bone • fontanels - spaces between unfused bones Mandible Sphenoid bone (a) Lateral view • two frontal bones fuse by age 6 (metopic suture) Frontal bone Anterior fontanel Sagittal suture • skull reaches adult size by 8 or 9 years of age Parietal bone Posterior fontanel (b) Superior view Figure 8. 17 8 -29

The Vertebral Column (Spine) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

The Vertebral Column (Spine) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • • • functions – supports the skull and trunk – allows for their movement – protects the spinal cord – absorbs stress of walking, running, and lifting – provides attachments for limbs thoracic cage, and postural muscles 33 vertebrae with intervertebral discs of fibrocartilage between most of them adult vertebral column averages 71 cm. (28 in. ) long – intervertebral discs account for about one-quarter of its length – person is 1% shorter when they go to bed – compression squeezes water out during the day and absorbs water when compression removed during sleep Anterior view Posterior view Atlas (C 1) Axis (C 2) Cervical vertebrae C 7 T 1 Thoracic vertebrae T 12 L 1 Lumbar vertebrae L 5 S 1 Sacrum S 5 Coccyx Figure 8. 18 Coccyx 8 -30

The Vertebral Column (Spine) • five vertebral groups – – 7 cervical in the

The Vertebral Column (Spine) • five vertebral groups – – 7 cervical in the neck 12 thoracic in the chest 5 lumbar in lower back 5 fused sacral at base of spine – 4 fused coccygeal • variations in number of lumbar and sacral vertebrae occur in 1 in 20 people Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Anterior view Posterior view Atlas (C 1) Axis (C 2) Cervical vertebrae C 7 T 1 Thoracic vertebrae T 12 L 1 Lumbar vertebrae L 5 S 1 Sacrum S 5 Coccyx Figure 8. 18 Coccyx 8 -31

Newborn Spinal Curvature Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Newborn Spinal Curvature Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • spine exhibits one continuous C-shaped curve at birth • known as primary curvature Figure 8. 20 © The Mc. Graw-Hill Companies, Inc. /Bob Coyle, photographer 8 -32

Adult Spinal Curvatures Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Adult Spinal Curvatures Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. C 1 Cervical curvature C 7 T 1 Thoracic curvature • s-shaped vertebral column with four normal curvatures – – cervical thoracic lumbar pelvic • primary curvatures – present at birth – thoracic and pelvic T 12 L 1 Lumbar curvature L 5 S 1 Pelvic curvature Figure 8. 19 • secondary curvatures – develop later – cervical and lumbar – lifting head as it begins to crawl develops cervical curvature – walking upright develops lumbar curvature 8 -33

Abnormal Spinal Curvatures Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Abnormal Spinal Curvatures Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • from disease, paralysis of trunk muscles, poor posture, pregnancy, or congenital defect • scoliosis – abnormal lateral curvature – – • (a) Scoliosis Key Normal Pathological (b) Kyphosis (“hunchback”) (c) Lordosis (“hunchback”) most common usually in thoracic region particularly of adolescent girls developmental abnormality in which the body and arch fail to develop on one side of the vertebrae kyphosis (hunchback) – exaggerated thoracic curvature – usually from osteoporosis, also osteomalacia or spinal tuberculosis, or wrestling or weightlifting in young boys Figure 8. 21 • lordosis (swayback) – exaggerated lumbar curvature – is from pregnancy or obesity 8 -34

General Structure of Vertebra • body (centrum) – mass of spongy bone that contains

General Structure of Vertebra • body (centrum) – mass of spongy bone that contains red bone marrow – covered with thin shell of compact bone – weight bearing portion – rough superior and inferior surfaces provide firm attachment for intervertebral discs • vertebral foramina – collectively form vertebral canal for spinal cord • vertebral arch Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Posterior Spinous process Lamina Superior articular facet Vertebral arch Transverse process Pedicle Vertebral foramen Body – composed of two parts on each side – pedicle – pillarlike and lamina - platelike • spinous process – projection extending from the apex of arch – extends posteriorly and downward • transverse process – extends laterally from point where pedicel and lamina meet • Nucleus pulposus superior articular processes – project upward from one vertebra and meets inferior articular processes from the vertebra above • Anterior (a) 2 nd lumbar vertebra (L 2) facets – flat articular surfaces covered with hyaline cartilage Anulus fibrosus (b) Intervertebral disc Figure 8. 22 8 -35

Intervertebral Foramen and Discs Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Intervertebral Foramen and Discs Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • – when two vertebrae are joined they exhibit and opening between their pedicles – passageway for spinal nerves – inferior vertebral notch in the pedicle of the upper vertebra – superior vertebral notch in the pedicle of the lower vertebra Superior articular process of L 1 Inferior vertebral notch of L 1 Intervertebral foramen Superior vertebral notch of L 2 • L 2 Spinous process Intervertebral disc L 3 Inferior articular process of L 3 (b) Left lateral view Figure 8. 23 b intervertebral foramen intervertebral discs (23) – first one between C 2 and C 3 – last one between L 5 and sacrum – pad consisting of: • nucleus pulposus - inner gelatinous mass • anulus fibrosus – outer ring of fibrocartilage – bind vertebrae together – support weight of the body – absorb shock – herniated disc (‘ruptured’ or ‘slipped’ disc) puts painful pressure on spinal nerve or spinal cord 8 -36

Cervical Vertebra C 1 - Atlas • atlas (C 1) Copyright © The Mc.

Cervical Vertebra C 1 - Atlas • atlas (C 1) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Transverse process Body (centrum) L 2 Intervertebral disc Inferior articular process of L 2 Superior articular process of L 3 Lamina Figure 8. 23 a L 3 (a) Posterior (dorsal) view – supports the head – has no body – a delicate ring surrounding a large vertebral foramen – lateral masses with superior articular facets • articulates with occipital condyles • allows nodding motion of skull gesturing ‘yes’ – inferior articular facets articulate with C 2 – anterior and posterior arches – anterior and posterior tubercles 8 -37

Cervical Vertebra C 2 - Axis • axis (C 2) Copyright © The Mc.

Cervical Vertebra C 2 - Axis • axis (C 2) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Dens (odontoid process) Body Superior articular facet Transverse foramen Transverse process Pedicle Inferior articular process Lamina Spinous process (b) Axis Figure 8. 24 b – allows rotation of the head gesturing ‘no’ – dens or odontoid process – prominent knob on its anterosuperior side • forms as an independent ossification center during first year of life • fuses with axis by age 3 to 6 years • projects into vertebral foramen of the atlas • held in place by a transverse ligament – atlanto-occipital joint – joint between atlas and cranium – atlantoaxial joint – joint between the atlas and axis 8 -38

Atlas and Axis Articulation Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Atlas and Axis Articulation Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Axis of rotation Dens Atlas Transverse ligament Figure 8. 24 c Axis (c) Atlantoaxial joint 8 -39

Typical Cervical Vertebrae Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Typical Cervical Vertebrae Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Superior views Lateral views Spinous process Lamina Superior articular facet Transverse foramen Transverse process Body (a) Cervical vertebrae • • Figure 8. 25 a Spinous process Inferior articular process C 1 -C 7 are the smallest and lightest vertebrae, other than the coccygeals bifid or forked spinous process in C 2 to C 6 small body and larger vertebral foramen transverse foramen in each short transverse process – provides passage and protection for: • vertebral arteries – supply blood to the brain • vertebral veins – drain blood from various neck structures – transverse foramen only found in cervical vertebrae • C 7 vertebra prominens – spinous process not bifid and especially long – prominent bump on the lower back of the neck – convenient landmark for counting vertebrae 8 -40

Typical Thoracic Vertebrae Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Typical Thoracic Vertebrae Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Spinous process Lamina Transverse costal facet Superior articular facet Transverse process Superior costal facet Figure 8. 25 b Transverse costal facet Inferior costal facet Body (b) Thoracic vertebrae • • • Inferior articular facet Spinous process 12 thoracic vertebrae (T 1 – T 12) – corresponds to the 12 pairs of ribs attached to them spinous processes pointed angled sharply downward larger body than cervical but, smaller than lumbar costal facets for attachment of ribs – on body as small, smooth, slightly concave spots transverse costal facets at end of each transverse process on T 1 – T 10 – provide second point of articulation for ribs 1 to 10 inferior and superior costal facets on vertebral body – - in most cases, ribs insert between the two vertebra 8 -41

Lumbar Vertebrae Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Lumbar Vertebrae Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Spinous process Superior articular facet Superior articular process Figure 8. 25 c Transverse process Pedicle Body Spinous process (c) Lumbar vertebrae Inferior articular facet • 5 lumbar vertebrae (L 1 – L 5) • thick, stout body • blunt, squarish spinous process • superior articular processes face medially – lumbar region resistant to twisting movements 8 -42

Sacrum (Anterior View) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Sacrum (Anterior View) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Superior articular process Sacral promontory Ala S 1 S 2 Transverse lines S 3 Anterior sacral foramina S 4 S 5 Coccyx Co 2 Co 1 Co 3 Co 4 (a) Anterior view Figure 8. 26 a • sacrum – bony plate that forms the posterior wall of the pelvic cavity • once considered the seat of the soul • in children, five separate sacral vertebrae (S 1 – S 5) • begin fusion around age 16 and complete fusion by age 26 • anterior surface – smooth and concave – 4 transverse lines indicate line of fusion of vertebrae – 4 pair of large anterior sacral (pelvic) foramina • allow for passage of nerves and arteries into the pelvic organs • sacral promontory on S 1 supports L 5 8 -43

Sacrum (Posterior View) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Sacrum (Posterior View) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Superior articular process Sacral canal Median sacral crest Auricular surface Lateral sacral crest • • – formed from fusion of spinous processes • Sacral hiatus Transverse process Coccyx (b) Posterior view Figure 8. 26 b lateral sacral crest – less prominent, and on either side of median sacral crest – formed from the fusion of the transverse processes • posterior sacral foramina – 4 pairs of openings for spinal nerves that supply gluteal region and lower limbs • Posterior sacral foramina Horn posterior surface very rough median sacral crest sacral canal runs through sacrum and ends as sacral hiatus – contains spinal nerve roots • • auricular surface is part of sacroiliac (SI) joint formed with hip bone superior articular processes on S 1 – articulates with L 5 • alae – pair of large, rough, winglike extensions lateral to the superior articular processes 8 -44

Coccyx • coccyx – usually consists of four small vertebrae (Co 1 – Co

Coccyx • coccyx – usually consists of four small vertebrae (Co 1 – Co 4) Sacral canal – sometimes five • fuse into a single, triangular Median sacral crest bone by age 20 – 30 Auricular • horns (cornua) on Co 1 surface Lateral sacral – serves as attachment crest points for ligaments that Posterior sacral foramina bind the coccyx to the Sacral hiatus sacrum • fractured during difficult Coccyx childbirth or by hard fall on Figure 8. 26 b buttocks • provide attachment for muscles of the pelvic floor 8 -45 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Superior articular process Horn Transverse process (b) Posterior view

Thoracic Cage • consists of thoracic vertebrae, sternum and ribs • forms conical enclosure

Thoracic Cage • consists of thoracic vertebrae, sternum and ribs • forms conical enclosure for lungs and heart • provides attachment for pectoral girdle and upper limbs • broad base and narrower apex • rhythmically expanded by respiratory muscles to draw air into the lungs • costal margin – inferior border of thoracic cage formed by the downward arc of ribs • protect thoracic organs, but also the spleen, most of the liver, and to some extent the kidneys 8 -46 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Sternoclavicular joint Sternum: Acromioclavicular joint T 1 1 Pectoral girdle: Clavicle Scapula Suprasternal notch Clavicular notch Manubrium 2 Angle 3 Body 4 True ribs (1– 7) 5 Xiphoid process 6 7 Costal cartilages 11 8 False ribs (8– 12) Floating ribs (11– 12) 9 10 12 T 12 L 1 Costal margin Figure 8. 27

Sternum • sternum (breastbone) – bony plate anterior to the heart • divided into

Sternum • sternum (breastbone) – bony plate anterior to the heart • divided into three regions: – manubrium • • broad superior portion suprasternal (jugular) notch medially clavicular notches – articulate with clavicle ribs attach along scalloped lateral margins – body (gladiolus) • longest part of sternum • sternal angle – point where body joins manubrium • ribs attach along scalloped lateral margins – xiphoid • inferior end of sternum • attachment for some of abdominal muscles • in cardiopulmonary resuscitation, improperly performed chest compressions can drive xiphoid process into the liver and cause fatal hemorrhage a 8 -47

Ribs • Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Ribs • Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Tubercle Neck Head Superior Inferior Angle Articular facet for transverse process Articular facets for vertebral bodies • Costal groove Shaft Figure 8. 28 b (b) Ribs 2– 10 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Superior articular facet Transverse costal facet for rib 6 Tubercle Superior costal facet for rib 6 • • Neck T 6 (b) Superior view Rib 6 Head Figure 8. 29 b • • 12 pairs of ribs – no difference between sexes – posterior (proximal) end attached to vertebral column – anterior (distal) ends mostly attached to the sternum – costal cartilages composed of hyaline cartilage attach anterior ends to sternum head – portion of the rib that articulates with the thoracic vertebrae – superior articular facet – inferior articular facet neck – narrow portion distal to the head tubercle – wider rough area distal to the neck – articulates with transverse costal facet of vertebra angle – lateral curve of rib shaft – long, gentle sloping, bladelike portion of rib – costal groove on inferior margin of 8 -48 shaft

Articulation of Rib 6 with Vertebrae T 5 and T 6 Copyright © The

Articulation of Rib 6 with Vertebrae T 5 and T 6 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Inferior costal facet of T 5 Vertebral body T 5 Superior articular facet of rib 6 Vertebral body T 6 Inferior articular facet of rib 6 Superior costal facet of T 6 Rib 6 (a) Anterior view Superior articular facet Transverse costal facet for rib 6 Tubercle Figure 8. 29 Superior costal facet for rib 6 T 6 Neck Head Rib 6 8 -49 (b) Superior view

True and False Ribs • true ribs (ribs 1 to 7) Copyright © The

True and False Ribs • true ribs (ribs 1 to 7) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Sternoclavicular joint Sternum: Acromioclavicular joint T 1 1 Pectoral girdle: Clavicle Scapula Suprasternal notch Clavicular notch Manubrium 2 Angle 3 Body 4 True ribs (1– 7) 5 Xiphoid process 6 7 Costal cartilages 11 8 False ribs (8– 12) Floating ribs (11– 12) 9 10 12 T 12 L 1 Costal margin Figure 8. 27 – each has its own costal cartilage connecting it to the sternum • false ribs (ribs 8 -12) – lack independent cartilaginous connection to the sternum – floating ribs (ribs 11 – 12) • articulate with bodies of vertebrae T 11 and T 12 • do not have tubercles • do not attach to transverse processes of the vertebra • no cartilaginous connection to the sternum or any of the higher costal cartilages 8 -50

Pectoral Girdle • pectoral girdle (shoulder girdle) – supports the arm • consists of

Pectoral Girdle • pectoral girdle (shoulder girdle) – supports the arm • consists of two bones on each side of the body – clavicle (collarbone) and scapula (shoulder blade) • clavicle articulates medially to the sternum and laterally to the scapula – sternoclavicular joint – acromioclavicular joint • scapula articulates with the humerus – glenohumeral joint - shoulder joint – easily dislocated due to loose attachment 8 -51

Clavicle Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Clavicle Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Sternal end Acromial end Conoid tubercle (a) Superior view Figure 8. 30 Conoid tubercle Sternal end Acromial end (b) Inferior view • • clavicle - S-shaped, somewhat flattened bone inferior – grooves and ridges for muscle attachment sternal end - rounded head acromial end – flattened – conoid tubercle – roughened tuberosity near acromial end – ligament attachment • braces the shoulder keeping upper limb away from the midline of the body 8 -52 • most frequently fractured bone in the body

Scapula • scapula – named for its resemblance to a spade or shovel •

Scapula • scapula – named for its resemblance to a spade or shovel • triangular plate that posteriorly overlies ribs 2 to 7 – three sides - superior, medial (vertebral) and lateral (axillary) borders – three angles – superior, inferior, and lateral angles • suprascapular notch – conspicuous notch on superior border – provides passage for a nerve • spine – transverse ridge on posterior surface – supraspinous fossa – indentation superior to the spine – infraspinous fossa – broad surface inferior to the spine • subscapular fossa – concave, anterior surface of scapula • complex lateral angle of scapula has three main features: – acromion – platelike extension of the spine • forms apex of the shoulder • articulates with the clavicle – the sole point of attachment of the scapula and the upper limb to the rest of the skeleton – coracoid process – shaped like a bent finger • provides attachment for tendons of the biceps brachii and other arm muscles – glenoid cavity – shallow socket that articulates with the head of the humerus • forming glenohumeral joint 8 -53

Scapula Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Scapula Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Superior border Suprascapular notch Superior angle Acromion Supraspinous fossa Coracoid process Glenoid cavity Lateral angle Spine Subscapular fossa Infraspinous fossa Lateral border Medial border Inferior angle (a) Anterior view (b) Posterior view Figure 8. 31 8 -54

Upper Limb • upper limb is divided into four regions containing a total of

Upper Limb • upper limb is divided into four regions containing a total of 30 bones per limb – brachium (arm proper) – extends from shoulder to elbow • contains only one bone - humerus – antebrachium (forearm) – extends from elbow to wrist • contains two bones - radius and ulna – carpus (wrist) • contains 8 small bones arranged in 2 rows – manus (hand) • 19 bones in 2 groups – 5 metacarpals in palm – 14 phalanges in fingers 8 -55

Humerus • proximal end Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Humerus • proximal end Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Greater tubercle Head Lesser tubercle Anatomical neck Surgical neck Intertubercular sulcus Nutrient foramen Deltoid tuberosity – hemispherical head that articulates with the glenoid cavity of scapula – anatomical neck – greater and lesser tubercles and deltoid tuberosity – intertubercular sulcus holds biceps tendon – surgical neck • distal end Coronoid fossa Radial fossa Lateral epicondyle Capitulum Medial supracondylar ridge Medial epicondyle Trochlea (a) Anterior view – rounded capitulum articulates with head of radius Figure 8. 32 – trochlea articulates with ulna – lateral and medial epicondyles – lateral and medial supracondylar ridges Lateral supracondylar – olecranon fossa holds ridge olecranon process of ulna Lateral epicondyle – coronoid fossa Olecranon 8 -56 – radial fossa (b) Posterior view

Radius Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Radius Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Olecranon Trochlear notch Radial notch of ulna Head of radius Neck of radius Head of radius Coronoid process • radius Neck of radius Ulnar tuberosity Radial tuberosity Ulna • superior surface articulates with capitulum on humerus • side of disc spins on radial notch on ulna Radius Interosseous borders Interosseous membrane Ulnar notch of radius Head of ulna Styloid process Articular facets (a) Anterior view – head – disc-shape, allows for rotation around the longitudinal axis of the bone during pronation and supination of hand – neck – radial tuberosity for biceps muscle – styloid process can be palpated near thumb – ulnar notch (b) Posterior view Figure 8. 33 8 -57

Ulna and Interosseous Membrane Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Ulna and Interosseous Membrane Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Olecranon Trochlear notch Radial notch of ulna Head of radius Neck of radius Head of radius Coronoid process Neck of radius Ulnar tuberosity Radial tuberosity Ulna Radius Interosseous borders Ulnar notch of radius Head of ulna Styloid process Articular facets (a) Anterior view – trochlear notch articulates with trochlea of humerus – olecranon – bony point at back of elbow – coronoid process – radial notch holds head of radius – styloid process • interosseous membrane Interosseous membrane Styloid process • ulna – ligament attaches radius to ulna along interosseous margin of each bone – enables the two elbow joints to share the load (b) Posterior view Figure 8. 33 8 -58

Carpal Bones • 8 bones form wrist Copyright © The Mc. Graw-Hill Companies, Inc.

Carpal Bones • 8 bones form wrist Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Distal phalanx II Middle phalanx II Key to carpal bones Distal row • 2 rows (4 bones each) Proximal row Proximal phalanx II IV Head Phalanges Body III Distal phalanx I II V Base I Proximal phalanx I Head Metacarpal Body bones Base Carpal bones First metacarpal Hamulus of hamate Hamate Pisiform Triquetrum Lunate (a) Anterior view Figure 8. 34 a Trapezoid Trapezium Carpal Capitate bones Scaphoid – allow movements of flexion, extension, abduction and adduction – proximal row – – scaphoid, lunate, triquetrum, and pisiform • pisiform is a sesamoid developed by age 9 to 12 in tendon of flexor carpi ulnaris muscle – distal row trapezium, trapezoid, capitate, and hamate 8 -59

Metacarpals and Phalanges • metacarpals - bones of the palm Copyright © The Mc.

Metacarpals and Phalanges • metacarpals - bones of the palm Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Distal phalanx II Middle phalanx II Key to carpal bones Distal row Proximal phalanx II IV Head Phalanges Body III Distal phalanx I II V Base I Proximal phalanx I Head Metacarpal Body bones Base Carpal bones First metacarpal Hamulus of hamate Hamate Pisiform Triquetrum Lunate (a) Anterior view Figure 8. 34 a – metacarpal I proximal to base of thumb – metacarpal V proximal to base of little finger – proximal base, body, and distal head Trapezoid Trapezium Carpal Capitate bones Scaphoid • phalanges - bones of the fingers – thumb or pollex has two phalanges • proximal and distal phalanx – fingers have three phalanges • proximal, middle and distal 8 -60 phalanx

Sesamoid Bone • pisiform – develops around age 9 – 12 years – in

Sesamoid Bone • pisiform – develops around age 9 – 12 years – in tendon of flexor carpi ulnaris muscle 8 -61

 • • pelvic girdle – consists of a complete ring composed of three

• • pelvic girdle – consists of a complete ring composed of three bones – two hip (coxal) bones • also called ossa coxae or innominate bones – sacrum that is also part of the vertebral column pelvis – bowl-shaped structure composed of the two coxal bones and sacrum as well as their ligaments and muscles that line the pelvic cavity and form its floor – supports trunk on the lower limbs and protects viscera, lower colon, urinary bladder, and internal reproductive organs Pelvic Girdle Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Iliac crest Iliac fossa Base of sacrum Ilium Sacroiliac joint Anterior superior iliac spine Pelvic surface of sacrum Anterior inferior iliac spine Pelvic inlet Spine • sacroiliac joint - joins hipbone to the vertebral column – auricular surface of ileum to auricular surface of sacrum Ischium Coccyx Acetabulum Body Interpubic disc Ramus Pubis Obturator foramen Superior ramus Inferior ramus Body Pubic symphysis (a) Anterosuperior view • • anteriorly, interpubic disc – pad of fibrocartilage joins pubic bones pubic symphysis – the interpubic disc and adjacent regions of the pubic bone on each side Figure 8. 35 a 8 -62

Pelvic Inlet and Outlet Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Pelvic Inlet and Outlet Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Iliac crest Iliac fossa Ilium Anterior superior iliac spine Anterior inferior iliac spine Spine Ischium Sacroiliac joint Pelvic surface of sacrum Pelvic brim Pelvic inlet Coccyx Pelvic inlet Acetabulum Body Ramus Pubis Greater pelvis Base of sacrum Superior ramus Inferior ramus Body Lesser pelvis Interpubic disc Obturator foramen Pubic symphysis (a) Anterosuperior view Figure 8. 35 a • • Pelvic outlet (b) Median section Figure 8. 35 b greater (false) pelvis – between flare of the hips lesser (true) pelvis – narrower and below pelvic brim – round margin that separates the two pelvic inlet – opening circumscribed by brim that infant’s head must pass during birth • pelvic outlet – lower margin of the lesser pelvis 8 -63

Hip Bone • • three distinct features of hip bone – iliac crest –

Hip Bone • • three distinct features of hip bone – iliac crest – superior crest of hip – acetabulum – the hip socket – obturator foramen – large hole below acetabulum each adult hip bone is formed by the fusion of three childhood bones – ileum • the largest • extends from the iliac crest to the center of the acetabulum • anterior and posterior superior spine • anterior and posterior inferior spines • greater sciatic notch and iliac fossa – ischium • inferioposterior portion of hip • heavy body with prominent spine • lesser sciatic notch • ischial tuberosity • ramus – pubis (pubic bone) • most anterior portion of the hip bone • body, superior and inferior ramus Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Ilium Ischium Pubis Iliac crest Anterior gluteal line Inferior gluteal line Anterior superior iliac spine Posterior gluteal line Posterior superior Iliac spine Posterior inferior Iliac spine Anterior r inferior iliac spine Greater sciatic notch Body of ilium Acetabulum Superior ramus of pubis Ischial spine Body of pubis Lesser sciatic notch Body of ischium Inferior ramus of pubis Ischial tuberosity Obturator foramen Ramus of ischium (a) Lateral view Figure 8. 36 a 8 -64

Comparison of Male and Female Copyright © The Mc. Graw-Hill Companies, Inc. Permission required

Comparison of Male and Female Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Male Female Pelvic brim Pelvic inlet Obturator foramen Pubic arch 90° Figure 8. 37 120° • male - heavier and thicker due to forces exerted by stronger muscles • female - wider and shallower, and adapted to the needs of pregnancy and childbirth, larger pelvic inlet and outlet for passage of infant’s head 8 -65

Lower Limb • lower limb divided into four regions containing 30 bones per limb

Lower Limb • lower limb divided into four regions containing 30 bones per limb – femoral region (thigh) – extends from hip to knee region • contains the femur and patella – crural region (leg proper) – extends from knee to ankle • contains medial tibia and lateral fibula – tarsal region (tarsus) – ankle – the union of the crural region with the foot • tarsal bones are considered part of the foot – pedal region (pes) - foot • composed of 7 tarsal bones, 5 metatarsals, and 14 phalanges in the toes 8 -66

Femur Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Femur Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • longest and strongest bone of the body • hemispherical head that articulates with the acetabulum of the pelvis Fovea capitis Greater trochanter – – Greater trochanter Head Neck Intertrochanteric crest Intertrochanteric line Lesser trochanter Spiral line • constricted neck • greater and lesser trochanters for muscle attachment • intertrochanteric crest – thick oblique ridge on the posterior surface that connects the trochanters • intertrochanteric line – more delicate ridge on the anterior surface that connects trochanters • linea aspera – ridge on posterior of the shaft Lateral supracondylar line • spiral (pectineal) line and gluteal tuberosity Lateral epicondyle • medial and lateral condyles and epicondyles found distally • intercondylar fossa • patellar and popliteal surface Gluteal tuberosity Linea aspera Shaft Medial supracondylar line Popliteal surface Lateral epicondyle Medial epicondyle Patellar surface Lateral condyle Intercondylar fossa Medial condyle Base of patella Articular facets Apex of patella (a) Anterior view Figure 8. 38 forms ball-and-socket joint fovea capitis – pit in head of femur for attachment of a ligament (b) Posterior view 8 -67

Patella (Kneecap) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or

Patella (Kneecap) Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Fovea capitis Greater trochanter Head Neck Intertrochanteric crest Intertrochanteric line Lesser trochanter Spiral line Gluteal tuberosity Linea aspera Shaft Medial supracondylar line Lateral supracondylar line Popliteal surface Lateral epicondyle Medial epicondyle Lateral epicondyle Patellar surface Lateral condyle Intercondylar fossa Medial condyle Base of patella Articular facets Apex of patella (a) Anterior view Figure 8. 38 (b) Posterior view • patella - triangular sesamoid bone embedded in tendon of the knee • cartilaginous at birth – ossifies at 3 to 6 year • base – broad, superior portion • apex – pointed, inferior portion • articular facets – shallow, posterior portion • quadriceps femoris tendon extends from the anterior muscle of the thigh to the patella – continues as the patellar ligament from the patella to the tibia 8 -68

Tibia Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Tibia Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Intercondylar eminence Medial condyle Lateral condyle Apex Head of fibula Tibial tuberosity Proximal tibiofibular joint Interosseous membrane Lateral surface Tibia Fibula Distal tibiofibular joint Medial malleolus (a) Anterior view Figure 8. 39 – only weight bearing bone of the crural region – broad superior head – medial and lateral condyles • fairly flat articular surfaces • articulate with condyle of femur Anterior crest Lateral malleolus • tibia - thick, medial, weightbearing bone Lateral malleolus – intercondylar eminence – ridge separating condyles – tibial tuberosity – attachment of quadricep muscles – anterior crest – sharp, angular – medial malleolus – bony knob on inside of ankle (b) Posterior view 8 -69

Fibula Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Fibula Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Intercondylar eminence Medial condyle Lateral condyle Apex Head of fibula Tibial tuberosity Proximal tibiofibular joint • does not bear any body weight – spare bone tissue for grafts Interosseous membrane Lateral surface • fibula – slender, lateral strut that helps stabilizes ankle • head - proximal end Anterior crest • apex – point of the head Tibia • lateral malleolus - distal expansion, bony knob on lateral side of ankle Fibula Distal tibiofibular joint Medial malleolus Lateral malleolus (a) Anterior view Figure 8. 39 • joined to tibia by interosseous membrane Lateral malleolus (b) Posterior view 8 -70

The Ankle and Foot • tarsal bones – arranged in proximal and distal groups

The Ankle and Foot • tarsal bones – arranged in proximal and distal groups • tarsal bones are shaped and arranged differently from carpal bones due to load-bearing role of the ankle • calcaneus – largest tarsal bone Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Distal phalanx I Distal phalanx V Proximal phalanx I Middle phalanx V Metatarsal I II – forms heel – distal portion is point of attachment for calcaneal (Achilles) tendon Proximal phalanx V III IV V • talus is most superior tarsal bone Medial cuneiform Intermediate cuneiform Lateral cuneiform Navicular Cuboid Talus Calcaneus Trochlear surface of talus Key to tarsal bones Distal group Tuberosity of calcaneus (a) Superior (dorsal) view Proximal group – forms ankle joint with tibia and fibula – sits upon calcaneus and articulates with navicular • proximal row of tarsal bones – talus, calcaneus, and navicular • distal row of tarsal bones Figure 8. 40 a – medial, intermediate and lateral cuneiforms and cuboid 8 -71

The Foot • remaining bones of foot are similar in name and arrangement to

The Foot • remaining bones of foot are similar in name and arrangement to the hand Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. • metatarsals Distal phalanx I Distal phalanx V Proximal phalanx I – metatarsal I is proximal to the great toe (hallux) – metatarsal V is proximal to the little toe – proximal base, intermediate shaft, and distal head Middle phalanx V Metatarsal I II Proximal phalanx V III IV V Medial cuneiform Intermediate cuneiform Lateral cuneiform Navicular Cuboid Talus • phalanges Calcaneus Trochlear surface of talus Key to tarsal bones Distal group Tuberosity of calcaneus (a) Superior (dorsal) view Proximal group – 2 in great toe • proximal and distal phalanx – 3 in all other toes • proximal, middle and distal phalanx Figure 8. 40 a 8 -72

Embryonic Limb Rotation Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction

Embryonic Limb Rotation Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Thumb Future thumb Elbow Knee Future great toe (a) Seven weeks Great toe (b) Eight weeks Figure 8. 41 • rotation of upper and lower limbs in opposite directions – – starts seventh week of embryonic development largest digit medial in foot and lateral in hand each limb rotates about 90° in opposite directions rotation also explains why elbow flexes posteriorly and knee flexes 8 -73 anteriorly

Foot Arches – sole of foot is not flat on ground – 3 springy

Foot Arches – sole of foot is not flat on ground – 3 springy arches absorb stress • medial longitudinal arch – from heel to hallux – formed from the calcaneus, talus, navicular, cuneiforms and metatarsals I and III • lateral longitudinal arch – from heel to little toe Medial – includes calcaneus, cuboid , and longitudinal arch metatarsals IV and V Transverse • transverse arch – across middle of foot Lateral – includes the cuboid, cuneiforms, and longitudinal proximal heads of metatarsals arch – arches held together by short, strong ligaments • pes planus (flat feet) – excessive weight, repetitious stress, or congenital weakness Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. (a) Inferior (plantar) view Figure 8. 42 a 8 -74

Skeletal Adaptations for Bipedalism • humans are only animals habitually bipedal – 3. 6

Skeletal Adaptations for Bipedalism • humans are only animals habitually bipedal – 3. 6 million year old human footprints indicate upright walking • adaptations – strong, springy foot arches – great toe not opposable – femurs angle inward so knees are closer together – erect posture requires less muscular effort – viscera supported in bowl-shaped pelvis – insertions of gluteal muscles differ from other primates 8 -75

Bipedalism and Limb Adaptations Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Bipedalism and Limb Adaptations Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. (a) Foot (b) Knee Chimpanzee Human Figure 8. 43(1)a, b 8 -76 Chimpanzee Human

Bipedalism and Upright Stance Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Bipedalism and Upright Stance Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. (c) Gluteal muscles Chimpanzee (d) Pelvis (e) Vertebral column Chimpanzee Human Figure 8. 43(1)c Human Figure 8. 43(2)d, e Human 8 -77

Bipedalism and Head Position Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for

Bipedalism and Head Position Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. (f) Skull Supraorbital ridge Pivot Foramen magnum Chimpanzee Pivot Figure 8. 43(2)f Foramen magnum Human 8 -78