copyright © 2010 pearson education, inc. the skeletal system ch. 5
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Copyright © 2010 Pearson Education, Inc.
THE SKELETAL SYSTEMCh. 5
Copyright © 2010 Pearson Education, Inc.
Five Functions of Bones
• Support
• For the body and soft organs
• Protection
• For brain, spinal cord, and vital organs
• Movement
• Levers for muscle action
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Functions of Bones
• Storage
• Minerals (calcium and phosphorus) and growth factors; Triglyceride (energy) storage in bone cavities
• Blood cell formation (hematopoiesis) in marrow cavities
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Classification of Bones by Shape
• Long bones
• Longer than they are wide
• All limb bones except carpals and tarsals, patella
• Short bones
• Cube-shaped bones (in wrist and ankle)
• Sesamoid bones (within tendons, e.g., patella)
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Classification of Bones by Shape
• Flat bones
• Thin, flat, slightly curved
• Examples: Sternum, scapulae, ribs most skull bones
• Irregular bones
• Complicated shapes
• Examples: coxal, vertebrae
Copyright © 2010 Pearson Education, Inc. Figure 6.2
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Bone Textures
• Compact bone
• Dense outer layer of bone
• Composed of osteons
• Spongy bone
• Internal to compact bone & composed of trabeculae
• No osteons
• Spaces between trabeculae are filled with bone marrow
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Membranes of Bone
• Periosteum
• Surrounds entire outer surface of compact bone, except joint surfaces
• Contains: Osteoblasts and osteoclasts
• Secured to compact bone by Sharpey’s fibers
• Endosteum
• Lines internal surfaces of bone and also contains osteoblasts and osteoclasts
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Structure of a Long Bone
• Diaphysis (shaft)
• Compact bone collar surrounds medullary (marrow) cavity
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Structure of a Long Bone
• Epiphyses
• Expanded ends
• Spongy bone interior
• Epiphyseal line (remnant of growth plate)
• Articular (hyaline) cartilage on joint surfaces
Copyright © 2010 Pearson Education, Inc. Figure 6.3a-b
Proximalepiphysis
(b)
(a)
Epiphysealline
Articularcartilage
Periosteum
Spongy bone
Compact bone
Medullarycavity (linedby endosteum)
Compact bone
Diaphysis
Distalepiphysis
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Structure of Short, Irregular, and Flat Bones
• Endosteum covered spongy bone surrounded/sandwiched by compact bone covered in periosteum
Copyright © 2010 Pearson Education, Inc. Figure 6.5
Compactbone
Trabeculae
Spongy bone(diploë)
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Chemical Composition of Bone: Organic
• Bone cells (osteoblasts, osteocytes, osteoclasts)
• Osteoid—organic bone matrix secreted by osteoblasts
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Chemical Composition of Bone: Inorganic
• Hydroxyapatites (mineral salts)
• 65% of bone by mass
• Mainly calcium phosphate crystals
• Responsible for hardness and resistance to compression
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Bone Formation, Growth and Remodeling
• Ossification- bone tissue formation
• Stages
• Bone formation—begins in the 2nd month of development
• Postnatal bone growth—until early adulthood
• Interstitial ( in length of long bones)and appositional ( in bone width & continues after adulthood)
• Bone remodeling and repair—lifelong
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Bone collarforms aroundhyaline cartilagemodel.
Cartilage in thecenter of thediaphysis calcifiesand then developscavities.
The periostealbud inavades theinternal cavitiesand spongy bonebegins to form.
The diaphysis elongatesand a medullary cavityforms as ossificationcontinues. Secondaryossification centers appearin the epiphyses inpreparation for stage 5.
The epiphysesossify. Whencompleted, hyalinecartilage remains onlyin the epiphysealplates and articularcartilages.
Hyalinecartilage
Area ofdeterioratingcartilage matrix
Epiphysealblood vessel
Spongyboneformation
Epiphysealplatecartilage
Secondaryossificationcenter
Bloodvessel ofperiostealbud
Medullarycavity
Articularcartilage
Childhood toadolescence
BirthWeek 9 Month 3
Spongybone
BonecollarPrimaryossificationcenter
1 2 3 4 5
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Control of Remodeling
• What controls continual remodeling of bone?
• Hormonal mechanisms that maintain calcium homeostasis in the blood
• Mechanical and gravitational forces
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Hormonal Control of Blood Ca2+
• Primarily controlled by parathyroid hormone (PTH)
Blood Ca2+ levels
Parathyroid glands release PTH
PTH stimulates osteoclasts to degrade bone matrix and release Ca2+
Blood Ca2+ levels
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Osteoclastsdegrade bonematrix and release Ca2+
into blood.
Parathyroidglands
Thyroidgland
Parathyroidglands releaseparathyroidhormone (PTH).
StimulusFalling bloodCa2+ levels
PTH
Calcium homeostasis of blood: 9–11 mg/100 mlBALANCEBALANCE
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Response to Mechanical Stress
• Curved bones are thickest where they are most likely to buckle
• Trabeculae form along lines of stress
• Large, bony projections occur where heavy, active muscles attach
Copyright © 2010 Pearson Education, Inc. Figure 6.13
Load here (body weight)
Head offemur
Compressionhere
Point ofno stress
Tensionhere
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Homeostatic Imbalances
• Read about Osteoporosis and focus on its risk factors, symptoms and characteristics
Copyright © 2010 Pearson Education, Inc. Figure 6.16
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THE SKELETON
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The Skeleton
• Two Major Divisions of the Skeletal System: Axial and Appendicular
• The Axial Skeleton Includes Three Regions:
• Skull and associated bones (aud. ossicles and hyoid)
• Vertebral column
• Thoracic cage
Copyright © 2010 Pearson Education, Inc. Figure 7.1a
Skull
Thoracic cage(ribs andsternum)
(a) Anterior view
Facial bonesCranium
Sacrum
Vertebralcolumn
ClavicleScapulaSternumRibHumerusVertebraRadiusUlnaCarpals
PhalangesMetacarpalsFemurPatella
TibiaFibula
TarsalsMetatarsalsPhalanges
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The Skull
•Two sets of bones
1. Cranial bones (8)
• Enclose the brain in the cranial cavity
• Calvaria:
• Cranial base: anterior, middle, and posterior cranial fossae
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The Skull
2. Facial bones
• Cavities for: special sense organs for sight, taste, and smell
• Provide sites of attachment for: teeth and muscles of facial expression
• All skull bones are joined by: sutures except temperomandibular joint(TMJ)
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Bones of cranium (cranial vault)
Lambdoidsuture
Facialbones
Squamoussuture
Coronalsuture
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Anterior cranialfossa
Middle cranialfossa
Posterior cranialfossa
(b) Superior view of the cranial fossae
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Frontal Bone
• Forms most of forehead
• Superior wall of orbits
Copyright © 2010 Pearson Education, Inc. Figure 7.4a
Parietal bone
Squamous part of frontal bone
(a) Anterior view
Frontal bone
Frontonasal suture
Supraorbital foramen(notch)Supraorbital margin
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Parietal Bones and Major Associated Sutures
• Superior and lateral aspects of craniaum
• Four sutures mark the articulations of parietal bones with frontal, occipital, and temporal bones:
1. Coronal suture—between parietal bones and frontal bone
2. Sagittal suture—between right and left parietal bones
3. Lambdoid suture—between parietal bones and occipital bone
4. Squamous (squamosal) sutures—between parietal and temporal bones on each side of skull
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Coronal suture Frontal boneSphenoid bone(greater wing)Parietal bone
Lambdoidsuture
Squamoussuture
Occipitalbone
(a) External anatomy of the right side of the skull
Temporal bone
Figure 7.5a
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Occipital Bone
• Most of skull’s posterior wall and posterior cranial fossa
• Articulates with 1st vertebra at occipital condyles
• Contains the foramen magnum
Copyright © 2010 Pearson Education, Inc. Figure 7.4b
Lambdoidsuture
Occipital bone
Superior nuchal line
Externaloccipitalprotuberance
(b) Posterior view
Occipitalcondyle
Parietalbone
Sagittal suture
Copyright © 2010 Pearson Education, Inc. Figure 7.6a
(a) Inferior view of the skull (mandible removed)
OccipitalCondyles
Foramen Magnum
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Temporal Bones
• Inferior to parietal bones
• External acoustic canal leads to eardrum
• Zygomatic process joins with cheek bone
• Mandibular fossa for mandible
Copyright © 2010 Pearson Education, Inc. Figure 7.8
Externalacousticmeatus
Mastoidprocess
Styloid process
Mandibular fossa
Zygomatic process
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Sphenoid Bone
• Complex, bat-shaped bone
• Processes : greater & lesser wings
• Contains the: sella turcica (for pituitary)
Copyright © 2010 Pearson Education, Inc. Figure 7.7a
Temporal bone(petrous part)
Parietal bone
Occipital bone
Foramen magnum
(a) Superior view of the skull, calvaria removed
Frontal bone
Olfactory foramina
Foramen rotundumForamen ovaleForamen spinosum
Foramen lacerum
Sphenoid Lesser wingGreater wing
View
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Body of sphenoid
Greaterwing
Superiororbitalfissure
Lesserwing
Pterygoidprocess
(b) Posterior view
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Ethmoid Bone
• Helps form the nasal septum
• Contains crista galli and cribriform plate for olfactory fibers to pass
Copyright © 2010 Pearson Education, Inc. Figure 7.4a
Parietal bone
Nasal boneSphenoid bone
Temporal boneEthmoid boneLacrimal boneZygomatic bone
(a) Anterior view
Frontal bone
Middle nasalconcha
Inferior nasal conchaVomer
Perpendicularplate
Ethmoidbone
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Hypophyseal fossaof sella turcica
Middle cranialfossa
Temporal bone(petrous part)
Posteriorcranial fossa
Parietal bone
Occipital bone
Foramen magnum
(a) Superior view of the skull, calvaria removed
Frontal bone
Olfactory foramina
Optic canal
Foramen rotundumForamen ovaleForamen spinosum
Jugular foramen
Hypoglossal canal
Foramen lacerum
Internal acousticmeatus
Cribriform plateEthmoidbone Crista galli
Sphenoid
Anterior cranial fossa
Lesser wingGreater wing
View
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Mandible
• Lower jaw
• Temporomandibular joint: only freely movable joint in skull
Copyright © 2010 Pearson Education, Inc. Figure 7.11a
Mandibularcondyle
Mandibular fossaof temporal bone
Temporomandibularjoint
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Maxillary Bones
• Medially fused to form upper jaw
• Carry teeth in the alveolar margin
Copyright © 2010 Pearson Education, Inc. Figure 7.11b
Articulates withfrontal bone
Alveolarmargin
(b) Maxilla, right lateral view
Copyright © 2010 Pearson Education, Inc. Figure 7.4a
Parietal bone
Nasal boneSphenoid bone
Temporal boneEthmoid boneLacrimal boneZygomatic bone
(a) Anterior view
Frontal bone
Inferior nasal conchaVomer
Ethmoidbone
Maxilla
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Zygomatic Bones
• Cheekbones
• Inferolateral margins of orbits
Copyright © 2010 Pearson Education, Inc. Figure 7.4a
(a) Anterior view
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Nasal Bones and Lacrimal Bones
• Nasal bones
• Form: bridge of nose
• Lacrimal bones
• In medial walls of orbits
• Lacrimal fossa houses lacrimal sac
Copyright © 2010 Pearson Education, Inc. Figure 7.5a
Lacrimal bone
Lacrimal fossa
(a) External anatomy of the right side of the skull
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Palatine Bones and Vomer
• Palatine bones
• Posterior one-third of hard palate
• Vomer
• Lower part of nasal septum
Copyright © 2010 Pearson Education, Inc. Figure 7.6a
Maxilla(palatine process)
Hardpalate
Vomer
(a) Inferior view of the skull (mandible removed)
Palatine bone(horizontal plate)
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Palatine bone
Sphenoidbone
Superiornasal conchaMiddlenasal concha
Ethmoidbone
Inferior nasalconcha
Nasal bone
• Inferior Nasal ConchaeForm part of lateral walls of nasal cavity
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Orbits
• Encase: eyes and lacrimal glands
• Sites of attachment for: eye muscles
• Formed by: parts of seven bones
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Optic canal
Zygomatic bone
Superiororbital fissure
(b) Contribution of each of the seven bones forming the right orbit
sphenoid bone
•Frontal bone
• Ethmoid bone
• Lacrimal bone
• Maxillary bone
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Hyoid Bone
• Not a bone of the skull
• Does not articulate directly with another bone
• Site of attachment for muscles of swallowing and speech
Copyright © 2010 Pearson Education, Inc. Figure 7.12
Greater horn
Lesser horn
Body
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THE SKELETAL SYSTEM: THE AXIAL SKELETON (CONT.)
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Vertebral Column
• Flexible curved structure containing 26 irregular bones (vertebrae)
• Cervical vertebrae (7)—vertebrae of the neck
• Thoracic vertebrae (12)—vertebrae of the thoracic cage
• Lumbar vertebrae (5)—vertebra of the lower back
• Sacrum—bone inferior to the lumbar vertebrae
• Coccyx—terminus of vertebral column
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Vertebral Column: Curvatures
• Increase the resilience and flexibility of the spine
• Primary curvatures
• Thoracic and sacral
• Present at birth
• Secondary curvatures
• Cervical and lumbar
• Form after birth (holding head upright, walking upright)
Copyright © 2010 Pearson Education, Inc. Figure 7.16
Cervical curvature (concave)
Thoracic curvature(convex)
Lumbar curvature(concave)
Sacral curvature(convex)
Coccyx
Anterior view Right lateral view
C1
Copyright © 2010 Pearson Education, Inc. Figure 7.37
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General Structure of Vertebrae
• Body
• Anterior, weight-bearing region
• Vertebral foramen
• Together make up vertebral canal for spinal cord
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General Structure of Vertebrae
• Seven processes per vertebra:
• Spinous process—projects posteriorly
• Transverse processes (2)—project laterally
• Superior articular processes (2)—protrude superiorly
• Inferior articular processes (2)—protrude inferiorly
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Posterior
Anterior
Lamina
Transverseprocess
Pedicle
Spinousprocess
Vertebralarch
VertebralforamenBody
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Cervical Vertebrae
• smallest, lightest vertebrae
• C3 to C7 share the following features
• Transverse foramen in: each transverse process
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Dens of axis
Transverse ligamentof atlasC1 (atlas)
C2 (axis)
Bifid spinousprocess
Transverse processes
C7 (vertebraprominens)
(a) Cervical vertebrae
C3
Inferior articularprocess
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Cervical Vertebrae
• C1 (atlas) and C2 (axis) have unique features
• Atlas (C1)
• No body or spinous process
• Superior articular facets articulate with the skull
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Anterior arch
Superiorarticularfacet
Transverseforamen
Posterior arch
Posterior
(a) Superior view of atlas (C1)
C1
Transverseprocess
Transverseforamen
Posterior arch
Posterior
Anteriorarch
(b) Inferior view of atlas (C1)
Inferiorarticularfacet
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Cervical Vertebrae
• Axis (C2)
• Dens projects superiorly into the anterior arch of the atlas
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C2
Posterior
Dens
(c) Superior view of axis (C2)
Inferiorarticularprocess
Body
Superiorarticularfacet
Transverseprocess
Pedicle
Lamina
Spinous process
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Thoracic Vertebrae
• T1 to T12
• All have costal facets for ribs
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Transverseprocess
Spinousprocess
Superior articularprocess
Transversecostal facet (fortubercle of rib)
Body
Inferior demifacet (for head of rib)
Inferior articularprocess
(b) Thoracic vertebrae
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Lumbar Vertebrae
• L1 to L5
• Short, thick pedicles and laminae
Copyright © 2010 Pearson Education, Inc. Table 7.2
Copyright © 2010 Pearson Education, Inc. Figure 7.20c
Superiorarticularprocess
Transverseprocess
Spinousprocess
Intervertebraldisc
Body
Inferiorarticularprocess
(c) Lumbar vertebrae
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Sacrum and Coccyx
• Sacrum
• 5 fused vertebrae (S1–S5)
• Forms: posterior wall of pelvis
• Sacral Canal
• Articulates with L5 superiorly, and with coxal bones laterally
• Coccyx
• Tailbone
• 3–5 fused vertebrae
• Articulates superiorly with: sacrum
Copyright © 2010 Pearson Education, Inc. Figure 7.21a
Coccyx
Body offirstsacralvertebra
(a) Anterior view
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Coccyx
Sacralcanal
Facet ofsuperiorarticular process
(b) Posterior view
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Thoracic (Rib) Cage
• Composed of
• Thoracic vertebrae
• Sternum
• Ribs and their costal cartilages
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Sternum
• Three fused bones
• Manubrium (superior)
• Body (middle)
• Xiphoid process (inferior)
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Ribs and Their Attachments
• 12 pairs
• All attach posteriorly to thoracic vertebrae
• Pairs 1 through 7
• True ribs
• Attach directly to the sternum by individual costal cartilages
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Ribs and Their Attachments
• Pairs 8 through10
• False ribs
• Attach indirectly to sternum by joining costal cartilage of rib above
• Pairs 11–12
• Floating ribs
• No attachment to sternum
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Trueribs(1–7)
Falseribs(8–10)
ManubriumSternal angleBodyXiphisternaljointXiphoidprocess
L1
Vertebra Floating ribs (11, 12)
Sternum
Costal cartilage
Copyright © 2010 Pearson Education, Inc. Figure 7.23b
Spinous processArticular faceton tubercle of rib
Neck of rib
Head of rib Body ofthoracicvertebra
Transversecostal facet(for tubercleof rib)
Superior costal facet(for head of rib)
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THE SKELETAL SYSTEM: THE APPENDICULAR SKELETON
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Pectoral Girdle (Shoulder Girdle)
• Clavicles and the scapulae
• Attach the upper limbs to the axial skeleton
Copyright © 2010 Pearson Education, Inc. Figure 7.24a
ClavicleAcromio-clavicularjoint
Scapula
(a) Articulated pectoral girdle
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Clavicles
• Acromial end (lateral end) articulates with the scapula
• Sternal end (medial) articulates with the sternum
Copyright © 2010 Pearson Education, Inc. Figure 7.24b
Acromial (lateral)end(b) Right clavicle, superior view
Posterior
Sternal (medial)end
Anterior
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Scapulae (Shoulder Blades)
• On dorsal surface of rib cage
• Glenoid cavity houses the head of humerus
• Spine is on posterior aspect
• Three fossa are the site of origin for the rotator cuff muscles: supraspinous, infraspinous and subscapular fossa
Copyright © 2010 Pearson Education, Inc. Figure 7.25a
Superior border
Subscapularfossa
Medial border
Glenoidcavity
Lateral border
(a) Right scapula, anterior aspect
Copyright © 2010 Pearson Education, Inc. Figure 7.25b
Superiorangle
Medial border
Coracoid processSuprascapular notch
Acromion
Glenoidcavityat lateralangle
Lateral border
Infraspinousfossa
Spine
(b) Right scapula, posterior aspect
Supraspinousfossa
Copyright © 2010 Pearson Education, Inc. Figure 7.25c
Coracoidprocess
Glenoidcavity
Acromion
Infraspinousfossa
Spine
(c) Right scapula, lateral aspect
Infraglenoidtubercle
Supraglenoidtubercle
Supraspinous fossa
Subscapularfossa
Inferior angle
Supraspinousfossa
Infraspinousfossa
Subscapularfossa
Posterior Anterior
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The Upper Limb
• Arm
• Humerus
• Forearm
• Radius and ulna
• Hand
• 8 carpal bones in the wrist
• 5 metacarpal bones in the palm
• 14 phalanges in the fingers
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Humerus
• Largest, longest bone of upper limb
• Head of Humerus articulates with: glenoid cavity of scapula
• Contains: Greater and Lesser Tubercles
• Articulates inferiorly with radius and ulna via the capitulum and trochlea respectively
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GreatertubercleLessertubercle
Capitulum
Head ofhumerus
Trochlea
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Bones of the Forearm
• Ulna
• Medial bone in forearm
• Contains olecranon process and trochlear notch
• Radius
• Lateral bone in forearm
• Contains radial head and ulnar notch
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Radialnotch ofthe ulna
OlecranonprocessTrochlearnotchCoronoidprocess
Radius
Head ofradius
InterosseousmembraneUlna
Head
Radius
(a) Anterior view (b) Posterior view
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Head ofradius
Capitulum
Trochlea
(c) Anterior view at the elbow region
Humerus
Coronoidprocess of ulna
Olecranonfossa
Olecranonprocess
(d) Posterior view of extended elbow
Humerus
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Hand: Carpus
• Eight bones in two rows
• Only scaphoid and lunate articulate with radius to form wrist joint
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Hand: Metacarpus and Phalanges
• Metacarpus
• Five metacarpal bones (#1 to #5) form the palm
• Phalanges
• Each finger (digit), except the thumb, has three phalanges—distal, middle, and proximal
• The thumb (pollex) has no middle phalanx
Copyright © 2010 Pearson Education, Inc. Figure 7.28a-b
• Trapezoid• Trapezium
• Scaphoid
Phalanges
Carpals
Radius
• Proximal• Middle• Distal
• Triquetrum• Lunate
• Capitate• Hamate
• Pisiform
Metacarpals
Carpals
(b) Posterior view of left hand
Ulna
• Trapezoid• Trapezium
• Scaphoid
Carpals
(a) Anterior view of left hand
Radius
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14.
18.
17.
16.15.
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Pelvic (Hip) Girdle
• Consists of Two coxal bones
• Attaches lower limbs to the axial skeleton with strong ligaments
• Transmits weight of upper body to lower limbs
• Each coxal bone consists of three fused bones:
• Ilium-
• Ischium-
• Pubis-
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IliumAla
Ischium
Obturator foramen
Acetabulum
Pubis
(a) Lateral view, right hip bone
Copyright © 2010 Pearson Education, Inc. Figure 7.29
Coxalbone
llium
Sacroiliacjoint
Iliac fossa
Pubicbone
Ischium
SacrumPelvic brim
Acetabulum
Pubic symphysis
Coccyx
Pubic arch
Anteriorsuperior iliac spine
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Comparison of Male and Female Pelves
• Female pelvis
• Adapted for childbearing
• True pelvis: (inferior to pelvic brim) defines birth canal
• Cavity of the true pelvis is broad, shallow, and has greater capacity
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Comparison of Male and Female Pelves
• Male pelvis
• Adapted for support of male’s heavier build and stronger muscles
• Cavity of true pelvis is narrow and deep
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The Lower Limb
• Three segments of the lower limb
• Thigh: femur
• Leg: tibia and fibula
• Foot: 7 tarsal bones in the ankle, 5 metatarsal bones in the metatarsus, and 14 phalanges in the toes
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Femur
• Largest and strongest bone in the body
• Femoral head articulates proximally with the acetabulum of the hip and distally with the tibia and patella
• Contains greater and lesser trochanters, medial and lateral condyles and patellar surface
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Greatertrochanter
Head
Lesser trochanter
Lateralcondyle
Intercondylar fossa
Medial condyle
Anterior view Posterior view(b) Femur (thigh bone)
Patellar surface
Posterior
ApexAnterior
(a) Patella (kneecap)
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Bones of the Distal Leg
• Tibia
• Medial leg bone
• Articulates with femur , fibula and talus
• Contains medial and lateral condyles, medial malleolus and anterior crest
• Fibula
• Lateral leg bone (Not weight bearing; no articulation with femur)
• Articulates with tibia at proximal and distal ends and with talus
• Contains fibular head and lateral malleolus
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Medial condyle
Interosseous membrane
Tibia
Proximal tibiofibularjoint
Distal tibiofibularjoint
Lateral condyle
Fibula
(a) Anterior view
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Foot: Tarsals
• Seven tarsal bones form the posterior half of the foot
• Talus transfers most of the weight from the tibia to the calcaneus
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Foot: Metatarsals and Phalanges
• Metatarsals:
• Five metatarsal bones (#1 to #5)
• Phalanges (The 14 bones of the toes)
• Each digit (except the hallux) has three phalanges- proximal, middle, distal
• The great toe (Hallux) has no middle phalanx
Copyright © 2010 Pearson Education, Inc. Figure 7.33a
Medialcuneiform
Phalanges
Metatarsals
TarsalsNavicular
Intermediatecuneiform
Talus
Calcaneus(a) Superior view
Cuboid
Lateralcuneiform
Proximal54321
Middle
Distal
Trochleaof talus
Copyright © 2010 Pearson Education, Inc. Figure 7.33b
Facet formedialmalleolus
Calcanealtuberosity(b) Medial view
Intermediatecuneiform Sustentac-
ulum tali(talar shelf)
Talus
Navicular
First metatarsal
Medialcuneiform
Calcaneus
PLAYPLAY Animation: Rotatable bones of the foot
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Joints (Articulations)
• Articulation—site where two or more bones meet
• Functions of joints:
• Give skeleton mobility
• Hold skeleton together
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Synovial Joints
Four Distinguishing features:
1. Articular cartilage: hyaline cartilage
2. Articular (joint) capsule:
3. Joint (synovial) cavity: small potential space
-encloses synovial fluid
4. Reinforcing ligaments
Copyright © 2010 Pearson Education, Inc.
Periosteum
Ligament
FibrouscapsuleSynovialmembrane
Joint cavity(containssynovial fluid)
Articular (hyaline)cartilage
Articularcapsule