the skeletal system - dr. michael...
TRANSCRIPT
8-1
The Skeletal System
• overview of the skeleton
• the skull
• the vertebral column and
thoracic cage
• the pectoral girdle and upper limb
• the pelvic girdle and lower limb
Figure 8.1a
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Skull
Frontal bone
Pectoralgirdle
Clavicle
Maxilla
Parietal bone
Mandible Mandible
Humerus
Femur
Fibula
Ulna
Radius
Scapula
Hip bone
Sacrum
Patella
Carpus
Thoraciccage
Pelvis
Sternum
Ribs
Costal cartilages
Phalanges
Metatarsal bones
Phalanges
Coccyx
Vertebral column
Metacarpalbones
Tarsus
(a) Anterior view
Tibia
8-2
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
8-4
Anatomical Features of BonesCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Sinuses
Crest
Foramen
Foramen
Fossae
HeadTubercle
Crest
Tuberosity
Line
Head
Fovea
Trochanters
Fossae
(a) Skull (lateral view)
Epicondyles
Condyles
Alveolus
SpineCondyleProcess
Lines
Meatus
(b) Scapula (posterior view)(c) Femur (posterior view)
(d) Humerus (anterior view)
Process
Spine
Figure 8.2
8-5
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
8-6
Major Skull Cavities
Figure 8.7
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Frontal bone
Ethmoid bone
Middle
Superior
Inferior Maxilla
Nasal cavity
Mandible
Vomer
Orbit
Cranial cavity
Nasalconchae
Oralcavity
Maxillarysinus
Zygomaticbone
Ethmoidair cells
8-7
Cranial Fossa
• cranium (braincase) – protects the brain and associated sense organs– swelling of the brain inside the rigid cranium may force tissue through
foramen magnum resulting in death
• base is divided into three basins that comprise the cranial floor– anterior cranial fossa holds the frontal lobe of the brain– middle cranial fossa holds the temporal lobes of the brain– posterior cranial fossa contains the cerebellum
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(a) Superior view
Posterior cranial fossa
Middle cranial fossa
Anterior cranial fossa
Cerebellum
Temporal lobe
Frontal lobe
(b) Lateral view
Anterior cranialfossa
Middle cranialfossa
Posterior cranialfossa
Figure 8.9
8-8
Frontal Bone• forms forehead and part of
the roof of the cranium
• coronal suture – posterior boundary of frontal bone
• contains frontal sinus
Figure 8.3
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Frontal bone
Coronal suture
Lacrimal bone
Squamous suture
Infraorbital foramen
Vomer
Mandible
Sphenoid bone
Ethmoid bone
Nasal bone
Zygomatic bone
Maxilla
Mental foramen
Temporal bone
Glabella
Mental protuberance
Parietal bone
Middle nasalconcha
Inferior nasalconcha
Supraorbitalmargin
Supraorbitalforamen
8-9
Parietal Bone• form most of cranial roof
and part of its lateral walls
• bordered by 4 sutures– sagittal – between parietal
bones– coronal – at anterior
margin– lambdoid – at posterior
margin– squamous – at lateral
border
Figure 8.4a
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Parietal bone
Frontal bone
Lambdoid suture
Sphenoid bone
Temporal bone
Zygomatic process
External acoustic meatus
Mandible
Temporal lines
Coronal suture
Ethmoid bone
Lacrimal bone
Nasal bone
Infraorbital foramen
Zygomatic bone
Temporal process
Zygomaticofacial foramen
Maxilla
Mental foramen
Occipital bone
Squamous suture
Mandibular condyle
Styloid process
Mastoid process
(a) Right lateral view
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Frontal bone
Coronal suture
Sagittal suture
Sutural bone
Parietal bone
Parietal foramen
Lambdoid suture
Occipital bone
Posterior
Anterior
Figure 8.6
8-10
Temporal Bone
• lateral wall and part of floor of cranial cavity– squamous part
• encircled by squamous suture
• zygomatic process• mandibular fossa
– tympanic part• external auditory meatus• styloid process
– mastoid part• mastoid process
Figure 8.4a
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Parietal bone
Frontal bone
Lambdoid suture
Sphenoid bone
Temporal bone
Zygomatic process
External acoustic meatus
Mandible
Temporal lines
Coronal suture
Ethmoid bone
Lacrimal bone
Nasal bone
Infraorbital foramen
Zygomatic bone
Temporal process
Zygomaticofacial foramen
Maxilla
Mental foramen
Occipital bone
Squamous suture
Mandibular condyle
Styloid process
Mastoid process
(a) Right lateral view
8-11
Temporal Bone
– part of cranial floor
• separates middle from posterior cranial fossa
• houses middle and inner ear cavities
• internal auditory meatus
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(b) Superior view of cranial floor
Cribriform foramina
Crista galli
Diploe (spongy bone)
Sphenoid bone
Temporal bone
Parietal bone
Occipital bone
Sella turcica
Frontal bone
Optic foramen
Foramen rotundum
Foramen ovale
Foramen spinosum
Foramen magnum
Jugular foramen
Hypoglossal canal
Internal acousticmeatus
Groove forvenous sinus
Petrous part oftemporal bone
Cribriform plateof ethmoid bone
Figure 8.5b
8-12
Occipital Bone• rear and base of skull
• foramen magnum holds spinal cord
• skull rests on atlas at occipital condyles
Figure 8.5a
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Zygomatic bone
Lambdoid suture
Foramen magnum
Mastoid foramen
Jugular foramen
Stylomastoid foramen
Carotid canal
Intermaxillary suture
Palatine bone
Greater palatine foramen
Medial pterygoid plate
Lateral pterygoid plate
Foramen ovale
Foramen spinosum
Foramen lacerum
Incisive foramen
Sphenoid bone
Zygomatic arch
Mandibular fossa
Styloid process
External acoustic meatus
Mastoid process
Mastoid notch
Condylar canal
Temporal bone
Superior nuchal line
Inferior nuchal line
Occipital bone
(a) Inferior view
Parietal bone
Occipital condyle
Vomer
Posterior nasalaperture
Palatine processof maxilla
Basilar part ofoccipital bone
External occipitalprotuberance
Sphenoid Bone
• optic foramen
8-13Figure 8.5b
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Lesser wing
Greater wing
Foramen ovale
Body
Lateral pterygoid plate
Medial pterygoid plate Pterygoid processes
(b) Posterior view
Dorsum sellae
Foramenrotundum
Superior orbitalfissure
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(b) Superior view of cranial floor
Cribriform foraminaCrista galli
Diploe (spongy bone)
Sphenoid bone
Temporal bone
Parietal bone
Occipital bone
Sella turcica
Frontal bone
Optic foramen
Foramen rotundumForamen ovaleForamen spinosum
Foramen magnum
Jugular foramen
Hypoglossal canal
Internal acousticmeatus
Groove forvenous sinus
Petrous part oftemporal bone
Cribriform plateof ethmoid bone
Figure 8.11b
8-14
Sphenoid Bone
Figure 8.11a
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Optic foramen
Lesser wing
Greater wing
Sella turcica
Dorsum sellae
Foramen rotundum
Hypophyseal fossa
Foramen ovaleForamen spinosum
(a) Superior view
Anterior clinoidprocess
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(b) Superior view of cranial floor
Cribriform foraminaCrista galli
Diploe (spongy bone)
Sphenoid bone
Temporal bone
Parietal bone
Occipital bone
Sella turcica
Frontal bone
Optic foramen
Foramen rotundumForamen ovaleForamen spinosum
Foramen magnum
Jugular foramen
Hypoglossal canal
Internal acousticmeatus
Groove forvenous sinus
Petrous part oftemporal bone
Cribriform plateof ethmoid bone
Figure 8.5b
8-15
Sphenoid Bone
sphenoid sinus
Figure 8.4b
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Coronal suture
Frontal bone
Sphenoid sinus
Frontal sinus
Crista galli
Parietal bone
Temporal bone
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Mandibular foramen
Styloid process
Squamous suture
Lambdoid sutureSella turcica
Occipital bone
Vomer
Palatine bone
Maxilla
Mandible
Mental spines
Nasal bone
(b) Median section
Cribriform plate ofethmoid bone
Perpendicular plateof ethmoid bone
Palatine processof maxilla
Figure 8.5a
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Zygomatic bone
Lambdoid suture
Foramen magnum
Mastoid foramen
Jugular foramen
Stylomastoid foramen
Carotid canal
Intermaxillary suture
Palatine bone
Greater palatine foramen
Medial pterygoid plate
Lateral pterygoid plate
Foramen ovale
Foramen spinosum
Foramen lacerum
Incisive foramen
Sphenoid bone
Zygomatic arch
Mandibular fossa
Styloid process
External acoustic meatus
Mastoid process
Mastoid notch
Condylar canal
Temporal bone
Superior nuchal line
Inferior nuchal line
Occipital bone
(a) Inferior view
Parietal bone
Occipital condyle
Vomer
Posterior nasalaperture
Palatine processof maxilla
Basilar part ofoccipital bone
External occipitalprotuberance
8-16
Ethmoid Bone
Figure 8.12
Supraorbital foramen
Orbital plate of ethmoid bone
Lacrimal bone
Optic foramen
Orbital plate of frontal bone
Lesser wing of sphenoid bone
Frontal process of maxillaSuperior orbital fissure
Roof oforbit
Orbital process ofpalatine bone
Orbital surface ofmaxilla
Floor oforbit
Medialwall
Zygomatic processof frontal bone
Greater wing ofsphenoid bone
Orbital surface ofzygomatic bone
Inferior orbitalfissure
Lateral wallof orbit
Infraorbitalforamen
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• between the eyes
• contributes to medial wall of orbit
• lateral walls and roof of nasal cavity, and nasal septum
Figure 8.14
Orbital plate
Crista galli
CribriformplateCribriformforamina
Ethmoidalcells
Perpendicularplate
Superiornasal concha
Middlenasal concha
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8-17
Ethmoid Bone
superior and middle concha
perpendicular plate of nasal septum
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Coronal suture
Frontal bone
Sphenoid sinus
Frontal sinus
Crista galli
Parietal bone
Temporal bone
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Mandibular foramen
Styloid process
Squamous suture
Lambdoid sutureSella turcica
Occipital bone
Vomer
Palatine bone
Maxilla
Mandible
Mental spines
Nasal bone
(b) Median section
Cribriform plate ofethmoid bone
Perpendicular plateof ethmoid bone
Palatine processof maxilla
Frontal sinus
Inferior
Anterior nasal spine
Maxilla
Incisive foramen
Lacrimal bone
Nasal bone
Nasal cartilages
Superior
Middle
Sphenoid sinus
Palatine bone
Sphenoid bone
Crista galli
Sella turcica
Cribriform plate
Cribriform foramina
Occipital bone
Lip
Frontal bone
Incisor
Nasal conchae:
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Figure 8.4b Figure 8.13
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 nasal bones
2 palatine bones 2 inferior nasal conchae
2 zygomatic bones 1 vomer
2 lacrimal bones 1 mandible
8-18
8-19
Maxillary Bones
Figure 8.3
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Frontal bone
Coronal suture
Lacrimal bone
Squamous suture
Infraorbital foramen
Vomer
Mandible
Sphenoid bone
Ethmoid bone
Nasal bone
Zygomatic bone
Maxilla
Mental foramen
Temporal bone
Glabella
Mental protuberance
Parietal bone
Middle nasalconcha
Inferior nasalconcha
Supraorbitalmargin
Supraorbitalforamen
Figure 8.5a
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Lambdoid suture
Foramen magnumMastoid foramen
Jugular foramenStylomastoid foramenCarotid canal
Intermaxillary suture
Palatine bone
Greater palatine foramen
Medial pterygoid plate
Lateral pterygoid plate
Foramen ovaleForamen spinosumForamen lacerum
(a) Inferior view
Palatine processof maxilla
Basilar part ofoccipital bone
External occipitalprotuberance
Zygomatic bone
Incisive foramen
Sphenoid bone
Zygomatic arch
Mandibular fossa
Styloid processExternal acoustic meatus
Mastoid processMastoid notch
Condylar canalTemporal bone
Superior nuchal line
Inferior nuchal line
Occipital bone
Parietal bone
Occipital condyle
Vomer
Posterior nasalaperture
8-20
Location of Maxillary Sinus
• maxillary sinus fills maxillae bone• larger in volume than frontal, sphenoid
and ethmoid sinuses
Figure 8.8
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Sphenoidsinus
Frontalsinus
Ethmoidsinus
Maxillarysinus
Figure 8.8
Palatine Bones• form the posterior portion
of the hard palate
Supraorbital foramen
Orbital plate of ethmoid bone
Lacrimal bone
Optic foramen
Orbital plate of frontal bone
Lesser wing of sphenoid bone
Frontal process of maxillaSuperior orbital fissure
Roof oforbit
Orbital process ofpalatine bone
Orbital surface ofmaxilla
Floor oforbit
Medialwall
Zygomatic processof frontal bone
Greater wing ofsphenoid bone
Orbital surface ofzygomatic bone
Inferior orbitalfissure
Lateral wallof orbit
Infraorbitalforamen
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Figure 8.148-21
Frontal sinus
Inferior
Anterior nasal spine
Maxilla
Incisive foramen
Lacrimal bone
Nasal bone
Nasal cartilages
Superior
Middle
Sphenoid sinus
Palatine bone
Sphenoid bone
Crista galli
Sella turcica
Cribriform plate
Cribriform foramina
Occipital bone
Lip
Frontal bone
Incisor
Nasal conchae:
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Figure 8.13
8-22
Zygomatic Bones
• forms angles of the cheekbones and part of lateral orbital wall
• zygomatic arch is formed from temporal process of zygomatic bone and zygomatic process of temporal bone
Figure 8.4a
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Parietal bone
Frontal bone
Lambdoid suture
Sphenoid bone
Temporal bone
Zygomatic process
External acoustic meatus
Mandible
Temporal lines
Coronal suture
Ethmoid bone
Lacrimal bone
Nasal bone
Infraorbital foramen
Zygomatic bone
Temporal process
Zygomaticofacial foramen
Maxilla
Mental foramen
Occipital bone
Squamous suture
Mandibular condyle
Styloid process
Mastoid process
(a) Right lateral view
8-23
Lacrimal Bones
• form part of medial wall of each orbit
• smallest bone of skull
• lacrimal fossa houses lacrimal sac in life– tears collect in lacrimal sac
and drain into nasal cavity
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Parietal bone
Frontal bone
Lambdoid suture
Sphenoid bone
Temporal bone
Zygomatic process
External acoustic meatus
Mandible
Temporal lines
Coronal suture
Ethmoid bone
Lacrimal bone
Nasal bone
Infraorbital foramen
Zygomatic bone
Temporal process
Zygomaticofacial foramen
Maxilla
Mental foramen
Occipital bone
Squamous suture
Mandibular condyle
Styloid process
Mastoid process
(a) Right lateral view
Figure 8.4a
8-24
Nasal Bones
• forms bridge of nose
• supports cartilages that shape lower portion of the nose
Figure 8.3
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Frontal bone
Coronal suture
Lacrimal bone
Squamous suture
Infraorbital foramen
Vomer
Mandible
Sphenoid bone
Ethmoid bone
Nasal bone
Zygomatic bone
Maxilla
Mental foramen
Temporal bone
Glabella
Mental protuberance
Parietal bone
Middle nasalconcha
Inferior nasalconcha
Supraorbitalmargin
Supraorbitalforamen
8-25
Vomer
• inferior half of the nasal septum– superior half formed by
perpendicular plate of ethmoid
• supports cartilage that forms the anterior part of the nasal septum
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Coronal suture
Frontal bone
Sphenoid sinus
Frontal sinus
Crista galli
Parietal bone
Temporal bone
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Mandibular foramen
Styloid process
Squamous suture
Lambdoid sutureSella turcica
Occipital bone
Vomer
Palatine bone
Maxilla
Mandible
Mental spines
Nasal bone
(b) Median section
Cribriform plate ofethmoid bone
Perpendicular plateof ethmoid bone
Palatine processof maxilla
Figure 8.4b
8-26
• strongest bone of the skull• only bone of skull that moves noticeably• supports lower teeth
• provides attachments for muscles of facial expression and mastication
MandibleCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Zygomatic bone
Lambdoid suture
Foramen magnum
Mastoid foramen
Jugular foramen
Stylomastoid foramen
Carotid canal
Intermaxillary suture
Palatine bone
Greater palatine foramen
Medial pterygoid plate
Lateral pterygoid plate
Foramen ovale
Foramen spinosum
Foramen lacerum
Incisive foramen
Sphenoid bone
Zygomatic arch
Mandibular fossa
Styloid process
External acoustic meatus
Mastoid process
Mastoid notch
Condylar canal
Temporal bone
Superior nuchal line
Inferior nuchal line
Occipital bone
(a) Inferior view
Parietal bone
Occipital condyle
Vomer
Posterior nasalaperture
Palatine processof maxilla
Basilar part ofoccipital bone
External occipitalprotuberance
Mandibular condylesCondylar process
Mandibular notch
Coronoid process
Mandibular foramen
Body
Angle
Ramus
Mental protuberance
Mental foramen
Alveolar process
Figure 8.5a
Figure 8.15
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Ramus, Angle and Body of Mandible
• 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
8-27
Figure 8.15
Mandibular condylesCondylar process
Mandibular notch
Coronoid process
Mandibular foramen
Body
Angle
Ramus
Mental protuberance
Mental foramen
Alveolar process
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8-28
• auditory ossicles
• 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
Bones Associated With Skull
Figure 8.16
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Hyoid
Larynx
Styloid process
Stylohyoid muscle
Greater horn
Lesser horn
Body
8-29
Skull in Infancy and Childhood• fontanels - spaces between
unfused bones– filled with fibrous membrane
– allow shifting of bones during birth and growth of brain
• two frontal bones fuse by age 6
• skull reaches adult size by 8 or 9 years of age
Figure 8.17
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Parietal bone
Occipital boneMaxilla
Frontal bone
Anterior fontanel
Sagittal suture
Posterior fontanel
Mandible
(b) Superior view
(a) Lateral view
Lambdoidsuture
Squamoussuture
Mastoidfontanel
Temporal bone
Parietalbone
Sphenoidbone
Coronalsuture
Frontalbone
Sphenoidfontanel
Nasalbone
Zygomaticbone
8-30
The Vertebral Column (Spine)• 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
Figure 8.18
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Cervical vertebrae
Thoracic vertebrae
Atlas (C1)
Axis (C2)
C7
Lumbar vertebrae
Sacrum
Coccyx Coccyx
Anterior view Posterior view
T1
T12
L1
L5
S1
S5
8-31
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
Figure 8.18
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Cervical vertebrae
Thoracic vertebrae
Atlas (C1)
Axis (C2)
C7
Lumbar vertebrae
Sacrum
Coccyx Coccyx
Anterior view Posterior view
T1
T12
L1
L5
S1
S5
8-32
General Structure of Vertebra• body (centrum)
– weight bearing portion– rough superior and inferior surfaces provide
firm attachment for intervertebral discs
• vertebral foramina– collectively form vertebral canal for spinal
cord
• spinous process– projection extending from the apex of arch– extends posteriorly and downward
• transverse process– extends laterally
• superior articular processes– project upward from one vertebra and
meets inferior articular processes from the vertebra above
• facets– flat articular surfaces covered with hyaline
cartilage
Figure 8.22
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Spinous process
Lamina
Pedicle
Body
(a) 2nd lumbar vertebra (L2)
Anterior
Posterior
Superior articularfacet
Transverseprocess
Vertebral foramen
Vertebralarch
Nucleus pulposus
Anulus fibrosus
(b) Intervertebral disc
8-33
Intervertebral Foramen and Discs• intervertebral foramen
– passageway for spinal nerves
• intervertebral discs (23)– first one between C2 and C3– last one between L5 and sacrum– 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
Figure 8.23b
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L1
L2
L3
Intervertebral disc
Spinous process
(b) Left lateral view
Superior articularprocess of L1
Inferior vertebralnotch of L1
Superior vertebralnotch of L2
Inferior articularprocess of L3
Intervertebralforamen
8-34
Cervical Vertebra C1 + C2
atlas (C1) articulates with occipital condyles allows nodding motion of skull gesturing ‘yes’
axis (C2) allows rotation of the head gesturing ‘no’
8-35
Cervical Vertebra C2 - Axis
• axis (C2)– allows rotation of the head gesturing ‘no’
8-36
Atlas and Axis Articulation
Figure 8.24c
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Dens
Axis of rotation
Atlas
Axis
Transverseligament
(c) Atlantoaxial joint
8-37
Sacrum and Coccyxsacrum – bony plate that forms the posterior wall of the pelvic cavityin children, five separate sacral vertebrae
coccyx – usually consists of four sometimes five, fuse into a single, triangular bone by age 20 – 30
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Transverse lines
Coccyx
Ala S1
S2
S3
S4
S5
Co1Co2Co3Co4
(a) Anterior view
Superior articularprocess
Sacralpromontory
Anterior sacralforamina
Figure 8.26a
8-38
Thoracic Cage
• consists of thoracic vertebrae, sternum and ribs
• provides attachment for pectoral girdle and upper limbs
Figure 8.27
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Sternoclavicular joint
Acromioclavicular joint
ClavicleScapula
Suprasternal notch
Clavicular notch
Manubrium
Angle
Body
Xiphoid process
Costal cartilages
Costal margin
True ribs (1–7)
1
2
3
4
5
6
7
8
9
10
11
12 T12
T1
L1
False ribs (8–12)
Sternum:
Pectoral girdle:
Floating ribs(11–12)
8-39
Sternum• sternum (breastbone) – bony plate anterior to the heart• divided into three regions:
– Manubrium
– body
– xiphoid
8-40
Articulation of Rib 6 with Vertebrae T5 and T6
Figure 8.29 Head
Neck
Tubercle
Rib 6
T6
(b) Superior view
Rib 6
Inferior costalfacet of T5
Superior articularfacet of rib 6
Inferior articularfacet of rib 6
Superior costalfacet of T6
(a) Anterior view
Vertebralbody T5
Vertebralbody T6
Transversecostal facetfor rib 6
Superiorarticularfacet
Superiorcostalfacetfor rib 6
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8-41
True and False Ribs• true ribs (ribs 1 to 7)
– 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)
Figure 8.27
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Sternoclavicular joint
Acromioclavicular joint
ClavicleScapula
Suprasternal notch
Clavicular notch
Manubrium
Angle
Body
Xiphoid process
Costal cartilages
Costal margin
True ribs (1–7)
1
2
3
4
5
6
7
8
9
10
11
12 T12
T1
L1
False ribs (8–12)
Sternum:
Pectoral girdle:
Floating ribs(11–12)
8-42
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
• scapula articulates with the humerus– glenohumeral joint - shoulder joint
8-43
Clavicle
• clavicle - S-shaped, somewhat flattened bone• inferior – grooves and ridges for muscle attachment• sternal end - rounded head• acromial end – flattened
• braces the shoulder keeping upper limb away from the midline of the body
Figure 8.30
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Conoid tubercle
Conoid tubercle
(a) Superior view
(b) Inferior view
Sternalend
Acromialend
Acromialend
Sternalend
8-44
Scapula• scapula
• lateral angle of scapula has three main features:– acromion
• forms apex of the shoulder• articulates with the clavicle
– coracoid process• 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
8-45
Scapula
Figure 8.31
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Superior angle
Acromion
Spine
Acromion
Inferior angle
(a) Anterior view (b) Posterior view
Suprascapularnotch
Coracoidprocess
Glenoidcavity
Subscapularfossa
Lateralborder
Medialborder
Superiorborder
Supraspinousfossa
Lateralangle
Infraspinousfossa
8-46
Upper Limb• Humerus
• Radius and ulna
• Carpal bones (wrist)
• 5 metacarpals in palm
• 14 phalanges in fingers
8-47
Humerus • proximal end– hemispherical head that
articulates with the glenoid cavity of scapula
– greater and lesser tubercles and deltoid tuberosity
– intertubercular sulcus holds biceps tendon
• distal end– rounded capitulum
articulates with head of radius– trochlea articulates with ulna – lateral and medial
epicondyles– olecranon fossa holds
olecranon process of ulna
Capitulum
Head
Trochlea(a) Anterior view (b) Posterior view
Greatertubercle
Lessertubercle
Intertubercularsulcus
Deltoidtuberosity
Coronoidfossa
Radialfossa
Lateralepicondyle
Surgicalneck
Greatertubercle
Anatomicalneck
Nutrientforamen
Deltoidtuberosity
Medialsupracondylar
ridge
Medialepicondyle
Lateralsupracondylarridge
Lateralepicondyle
Olecranonfossa
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Figure 8.32
8-48
Radius
• radius– head – disc-shape, allows for
rotation around the longitudinal axis of the bone during pronation and supination of hand
• superior surface articulates with capitulum on humerus
• side of disc spins on radial notch on ulna
– radial tuberosity for biceps muscle
– styloid process can be palpated near thumb
– ulnar notch
Figure 8.33
Olecranon Olecranon
(a) Anterior view (b) Posterior view
Articular facets
Ulna
Radius
Ulnar tuberosity
Coronoid process
Trochlear notch
Radial notchof ulna
Head ofradiusNeck ofradius
Radialtuberosity
Styloidprocess
Interosseousborders
Interosseousmembrane
Ulnar notchof radius
Head of ulna
Styloid processStyloidprocess
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Head ofradius
Neck ofradius
8-49
Ulna and Interosseous Membrane
• ulna– 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– ligament attaches radius to
ulna along interosseous margin of each bone
– enables the two elbow joints to share the load
Figure 8.33
Olecranon Olecranon
(a) Anterior view (b) Posterior view
Articular facets
Ulna
Radius
Ulnar tuberosity
Coronoid process
Trochlear notch
Radial notchof ulna
Head ofradiusNeck ofradius
Radialtuberosity
Styloidprocess
Interosseousborders
Interosseousmembrane
Ulnar notchof radius
Head of ulna
Styloid processStyloidprocess
Head ofradius
Neck ofradius
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8-50
Carpal Bones
Figure 8.34a
I
IIIIIIV
V
Distal phalanx II
Middle phalanx II
Proximal phalanx II
Head
Body
Base
Hamulus of hamateHamatePisiformTriquetrumLunate
CapitateTrapeziumTrapezoid
Body
Head
Scaphoid
Base
Phalanges
Key to carpal bones
Distal row
Proximal row
Distalphalanx I
Proximalphalanx I
Firstmetacarpal
Carpalbones
Metacarpalbones
Carpalbones
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(a) Anterior view
8-51
Metacarpals and Phalanges
Figure 8.34a
I
IIIIIIV
V
Distal phalanx II
Middle phalanx II
Proximal phalanx II
Head
Body
Base
Hamulus of hamateHamatePisiformTriquetrumLunate
CapitateTrapeziumTrapezoid
Body
Head
Scaphoid
Base
Phalanges
Key to carpal bones
Distal row
Proximal row
Distalphalanx I
Proximalphalanx I
Firstmetacarpal
Carpalbones
Metacarpalbones
Carpalbones
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(a) Anterior view
8-52
Pelvic Girdle• 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 limbsand protects viscera, lower colon, urinary bladder, and internal reproductive organs
• sacroiliac joint - joins hipbone tothe vertebral column
– auricular surface of ileum to auricular surface of sacrum
• 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 8.35a
Ilium
Ischium
Coccyx
Body
Ramus
Pubis
(a) Anterosuperior view
Pubic symphysis
Acetabulum
Spine
Pelvic inlet
Sacroiliac joint
Body
Superior ramus
Inferior ramus
Iliaccrest
Iliacfossa
Anteriorsuperioriliac spine
Anterior inferioriliac spine
Base ofsacrum
Pelvic surfaceof sacrum
Interpubicdisc
Obturatorforamen
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8-53
Pelvic Inlet and Outlet
• 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
Figure 8.35bFigure 8.35a
Ilium
Ischium
Coccyx
Body
Ramus
Pubis
(a) Anterosuperior view
Pubic symphysis
Acetabulum
Spine
Pelvic inlet
Sacroiliac joint
Body
Superior ramus
Inferior ramus
Iliaccrest
Iliacfossa
Anteriorsuperioriliac spine
Anterior inferioriliac spine
Base ofsacrum
Pelvic surfaceof sacrum
Interpubicdisc
Obturatorforamen
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(b) Median section
Pelvic inlet
Pelvic brim
Greater pelvis
Pelvic outlet
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Lesserpelvis
8-54
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
– ischium
– pubis (pubic bone)
Figure 8.36a
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Ilium Ischium Pubis
Posterior superiorIliac spine
Anterior superioriliac spine
Greater sciatic notch
Inferior glutealline
Anterior glutealline
Ischial spine
Acetabulum
Ischial tuberosity
(a) Lateral view
Body of ischium
Lesser sciatic notch
Iliac crest
Anterior inferioriliac spine
r
Body of ilium
Body of pubis
Inferior ramusof pubis
Obturator foramen
Ramus of ischium
Superior ramusof pubis
Posterior glutealline
Posterior inferiorIliac spine
8-55
Comparison of Male and Female
• 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
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Male Female
90 120Pubic arch
Obturator foramen
Pelvic inlet
Pelvic brim
Figure 8.37
8-56
Lower Limb• Femur (upper leg)• Patella (knee cap)• medial tibia and lateral fibula (lower leg)• 7 tarsal bones, 5 metatarsals, and 14 phalanges in the toes (foot)
8-57
Femur • head that articulates with the acetabulum of the pelvis
– forms ball-and-socket joint
• greater and lesser trochanters for muscle attachment
• medial and lateral condyles and epicondyles found distally
Figure 8.38
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Greater trochanter
Intertrochanteric line
Lateral epicondyle
Patellar surface
(b) Posterior view
Lateral epicondyle
Medial supracondylar line
Lateral condyle
Linea aspera
Intertrochanteric crest
Gluteal tuberosity
Greater trochanterHead
Fovea capitis
Neck
Lesser trochanter
Spiral line
Shaft
Medial epicondyle
Popliteal surface
Medial condyle Intercondylar fossa
Base of patellaArticular facets
Apex of patella
Lateral supracondylarline
(a) Anterior view
8-58
Tibia• tibia - thick, medial, weight-
bearing bone– medial and lateral condyles
• fairly flat articular surfaces• articulate with condyle of
femur
– tibial tuberosity – attachment of quadricep muscles
– medial malleolus – bony knob on inside of ankle
Lateral condyle
Apex
Head of fibula
Intercondylar eminence
Lateral surface
Distal tibiofibular joint
Lateral malleolus
Fibula
Anterior crest
Lateral malleolus
(b) Posterior view
Proximal tibiofibularjoint
Tibia
Medial malleolus
Medialcondyle
Tibialtuberosity
Interosseousmembrane
(a) Anterior view
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Figure 8.39
8-59
Fibula• fibula – slender, lateral
strut that helps stabilizes ankle
• does not bear any body weight
• lateral malleolus - distal expansion, bony knob on lateral side of ankle
• joined to tibia by interosseous membrane
Lateral condyle
Apex
Head of fibula
Intercondylar eminence
Lateral surface
Distal tibiofibular joint
Lateral malleolus
Fibula
Anterior crest
Lateral malleolus
(b) Posterior view
Proximal tibiofibularjoint
Tibia
Medial malleolus
Medialcondyle
Tibialtuberosity
Interosseousmembrane
(a) Anterior view
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Figure 8.39
8-60
The Ankle and Foot• tarsal bones – arranged in
proximal and distal groups
• calcaneus – largest tarsal bone– forms heel– distal portion is point of attachment
for calcaneal (Achilles) tendon• talus is most superior tarsal bone
– forms ankle joint with tibia and fibula
– sits upon calcaneus and articulates with navicular
Key to tarsal bones
Distal group
Proximal group
Distal phalanx I
Proximal phalanx I
Metatarsal
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform
Navicular
Talus
(a) Superior (dorsal) view
Calcaneus
Cuboid
V
IVIIIIII
Trochlear surfaceof talus
Tuberosity of calcaneus
Proximalphalanx V
Middlephalanx V
Distalphalanx V
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Figure 8.40a
8-61
The Foot• remaining bones of foot are
similar in name and arrangement to the hand
• metatarsals
• phalanges
Key to tarsal bones
Distal group
Proximal group
Distal phalanx I
Proximal phalanx I
Metatarsal
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform
Navicular
Talus
(a) Superior (dorsal) view
Calcaneus
Cuboid
V
IVIIIIII
Trochlear surfaceof talus
Tuberosity of calcaneus
Proximalphalanx V
Middlephalanx V
Distalphalanx V
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Figure 8.40a