Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The Skeletal System Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parietal bone Frontal bone Skull • overview of the skeleton Maxilla Mandible Mandible Pectoral girdle Clavicle Scapula Sternum • the skull Thoracic cage Humerus Ribs Costal cartilages Vertebral column • the vertebral column and thoracic cage 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 8.1a 8-1 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 defined in Table 8.2 – ridges, spines, bumps, depressions, canals, pores, slits, cavities, 8-2 and articular surfaces Axial and Appendicular Skeleton Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parietal bone Frontal bone Skull Pectoral girdle Occipital bone Maxilla Mandible Mandible Clavicle Clavicle Scapula 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 Phalanges (a) Anterior view Figure 8.1 (b) Posterior view 8-3 Anatomical Features of Bones Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lines Crest Sinuses Foramen Fovea Head Meatus Crest Trochanters Process Condyle Spine Head Tubercle Alveolus Foramen Tuberosity (a) Skull (lateral view) Line Process Fossae Spine Epicondyles Fossae Condyles (b) Scapula (posterior view) Figure 8.2 (c) Femur (posterior view) (d) Humerus (anterior view) 8-4 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 8-5 Major Skull Cavities Copyright © The McGraw-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 Maxilla Maxillary sinus Vomer Nasal cavity Oral cavity Mandible Figure 8.7 8-6 Cranial Fossa Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Figure 8.9 Frontal lobe Anterior cranial fossa Temporal lobe Middle cranial fossa Cerebellum Posterior cranial fossa Posterior cranial fossa Middle cranial fossa Anterior cranial fossa (a) Superior view • • (b) Lateral view 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 – consists of two parts: the calvaria (skullcap) and the cranial base base is divided into three basins that comprise the cranial floor 8-7 Frontal Bone • forms forehead and part of the roof of the cranium Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • coronal suture – posterior boundary of frontal bone Frontal bone Glabella Coronal suture Supraorbital foramen Parietal bone Supraorbital margin Squamous suture • supraorbital foramen provides passage for nerve, artery, and vein Lacrimal bone Ethmoid bone Nasal bone Middle nasal concha Zygomatic bone Infraorbital foramen Vomer • contains frontal sinus Temporal bone Sphenoid bone Inferior nasal concha Maxilla Mandible Mental protuberance Mental foramen Figure 8.3 8-8 Parietal Bone Copyright © The McGraw-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 8.4a Copyright © The McGraw-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 8-9 Temporal Bone • lateral wall and part of floor of cranial cavity – squamous part • zygomatic process • mandibular fossa Copyright © The McGraw-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 – tympanic part • external auditory meatus • styloid process 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 Figure 8.4a – mastoid part • mastoid process – mastoiditis from ear infection • stylomastoid foramen • mastoid foramen 8-10 Petrous Portion of Temporal Bone – petrous part • part of cranial floor Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Diploe (spongy bone) Frontal bone Crista galli Cribriform plate of ethmoid bone Cribriform foramina • houses middle and inner ear cavities Sphenoid bone Optic foramen Sella turcica Foramen rotundum Foramen ovale Temporal bone Foramen spinosum Internal acoustic meatus • receptors for hearing and sense of balance 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 8.5b • internal auditory meatus - opening for CN VII (vestibulocochlear nerve) • carotid canal • jugular foramen 8-11 Occipital Bone • • rear and base of skull foramen magnum holds spinal cord Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Incisive foramen Palatine process of maxilla Intermaxillary suture Zygomatic bone • • skull rests on atlas at occipital condyles hypoglossal canal transmits hypoglossal nerve (CN XII) supplying tongue muscles 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 Figure 8.5a 8-12 Sphenoid Bone Copyright © The McGraw-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 8.11b Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • body • greater wing • lesser wing • optic foramen 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 (b) Superior view of cranial floor Figure 8.5b 8-13 Sphenoid Bone Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-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 Greater palatine 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 External acoustic meatus Occipital condyle (b) Median section 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 External occipital protuberance Superior nuchal line Figure 8.4b Occipital bone (a) Inferior view Figure 8.5a sphenoid sinus 8-14 Ethmoid Bone Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Supraorbital foramen Roof of orbit Lesser wing of sphenoid bone Orbital plate of ethmoid bone Lacrimal bone Lateral wall of orbit • contributes to medial wall of orbit • lateral walls and roof of nasal cavity, and nasal septum • cribriform plate – forms roof of nasal cavity Orbital surface of zygomatic bone Superior orbital fissure Frontal process of maxilla Orbital process of palatine bone Floor of orbit between the eyes Zygomatic process of frontal bone Greater wing of sphenoid bone Optic foramen Medial wall • Orbital plate of frontal bone Inferior orbital fissure Infraorbital foramen Orbital surface of maxilla Figure 8.14 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cribriform plate Cribriform foramina Orbital plate Ethmoidal cells Perpendicular plate Crista galli Superior nasal concha Middle nasal concha – ethmoid cells in the make up ethmoid sinuses Figure 8.12 8-15 Ethmoid Bone Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Crista galli Parietal bone Frontal bone Cribriform plate Sphenoid sinus Frontal 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 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 8.4b 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 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 McGraw-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 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 McGraw-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 8.5a (a) Inferior view 8-18 Location of Maxillary Sinus Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sphenoid sinus Frontal sinus Ethmoid sinus Maxillary sinus FigureFigure 8.8 8.8 • maxillary sinus fills maxillae bone • larger in volume than frontal, sphenoid and ethmoid sinuses 8-19 Palatine Bones Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • L-shaped bone Crista galli Frontal bone Cribriform plate Frontal sinus • form the posterior portion of the hard palate 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 Anterior nasal spine Palatine bone Incisive foramen Lacrimal bone Lip Maxilla Incisor Figure 8.13 • part of the orbital floor Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Supraorbital foramen • greater palatine foramina Roof of orbit 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 Lacrimal bone Superior orbital fissure Frontal process of maxilla Inferior orbital fissure Orbital process of palatine bone Floor of orbit Lateral wall of orbit Infraorbital foramen Orbital surface of maxilla Figure 8.14 8-20 Zygomatic Bones Copyright © The McGraw-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 8.4a • zygomatic arch is formed from temporal process of zygomatic bone and zygomatic process of temporal bone 8-21 Lacrimal Bones Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone Temporal lines Lambdoid suture Ethmoid bone Sphenoid bone • form part of medial wall of each orbit • smallest bone of skull Nasal bone Occipital bone Lacrimal bone Squamous suture Zygomaticofacial foramen Temporal bone Infraorbital foramen Zygomatic process External acoustic meatus Zygomatic bone Maxilla Mastoid process Temporal process Styloid process • lacrimal fossa houses lacrimal sac in life Mandible Mandibular condyle Mental foramen (a) Right lateral view – tears collect in lacrimal sac and drain into nasal cavity Figure 8.4a 8-22 Nasal Bones Copyright © The McGraw-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 Supraorbital foramen Parietal bone Supraorbital margin Squamous suture 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 Vomer Copyright © The McGraw-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 8.4b • supports cartilage that forms the anterior part of the nasal septum 8-24 Mandible Copyright © The McGraw-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 mental foramen Figure 8.5a 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 McGraw-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 Figure 8.15 Angle Body 8-25 Ramus, Angle and Body of Mandible Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • 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 Mandibular condyles Condylar process Coronoid process Mandibular notch Mandibular foramen Ramus Alveolar process Mental foramen Mental protuberance Angle Body Figure 8.15 • mandibular foramen 8-26 Bones Associated With Skull • auditory ossicles – three in each middle-ear cavity – malleus, incus, and stapes Copyright © The McGraw-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 8-27 Skull in Infancy and Childhood Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Coronal suture Frontal bone Parietal bone • fontanels - spaces between unfused bones – 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 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 8-28 The Vertebral Column (Spine) Copyright © The McGraw-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 Anterior view Posterior view Atlas (C1) Axis (C2) Cervical vertebrae C7 T1 Thoracic vertebrae 33 vertebrae with intervertebral discs of fibrocartilage between most of them T12 • 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 L1 Lumbar vertebrae L5 S1 Sacrum S5 Coccyx Figure 8.18 Coccyx 8-29 The Vertebral Column (Spine) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • 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 Anterior view Posterior view Atlas (C1) Axis (C2) Cervical vertebrae C7 T1 Thoracic vertebrae T12 L1 • variations in number of lumbar and sacral vertebrae occur in 1 in 20 people Lumbar vertebrae L5 S1 Sacrum S5 Coccyx Figure 8.18 Coccyx 8-30 Adult Spinal Curvatures Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • C1 – – – – Cervical curvature C7 T1 Thoracic curvature s-shaped vertebral column with four normal curvatures • cervical thoracic lumbar pelvic primary curvatures – present at birth – thoracic and pelvic T12 • L1 Lumbar curvature L5 S1 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 8-31 Abnormal Spinal Curvatures Copyright © The McGraw-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 8-32 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 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 from point where pedicel and lamina meet processes from the vertebra above Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Posterior Spinous process Lamina Superior articular facet Vertebral arch Transverse process Pedicle Vertebral foramen Body Anterior (a) 2nd lumbar vertebra (L2) Nucleus pulposus Anulus fibrosus (b) Intervertebral disc Figure 8.22 8-33 Intervertebral Foramen and Discs Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • intervertebral foramen – passageway for spinal nerves • intervertebral discs (23) – first one between C2 and C3 – last one between L5 and sacrum – pad 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 Superior articular process of L1 Inferior vertebral notch of L1 L1 Intervertebral foramen Superior vertebral notch of L2 L2 Spinous process Intervertebral disc L3 Inferior articular process of L3 (b) Left lateral view Figure 8.23b 8-34 Cervical Vertebra C1 - Atlas • atlas (C1) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Transverse process Body (centrum) – supports the head – has no body • allows nodding motion of skull gesturing ‘yes’ L2 Intervertebral disc Inferior articular process of L2 Superior articular process of L3 Lamina Figure 8.23a L3 (a) Posterior (dorsal) view 8-35 Cervical Vertebra C2 - Axis • axis (C2) – allows rotation of the head gesturing ‘no’ Copyright © The McGraw-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 8.24b 8-36 Sacrum (Anterior View) • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Superior articular process • Sacral promontory Ala S1 • S2 • Transverse lines S3 • Anterior sacral foramina S4 S5 Coccyx Co2 Co1 Co3 Co4 (a) Anterior view 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 (S1 – S5) begin fusion around age 16 and complete fusion by age 26 anterior surface – 4 pair of large anterior sacral (pelvic) foramina • allow for passage of nerves and arteries into the pelvic organs Figure 8.26a 8-37 Coccyx • coccyx – usually consists of four small vertebrae (Co1 – Co4) Sacral canal – sometimes five • fuse into a single, triangular Median sacral crest bone by age 20 – 30 Auricular • fractured during difficult surface Lateral sacral childbirth or by hard fall on crest buttocks Posterior sacral foramina • provide attachment for Sacral hiatus muscles of the pelvic floor Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Superior articular process Horn Transverse process Coccyx Figure 8.26b (b) Posterior view 8-38 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 8-39 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sternoclavicular joint Sternum: Acromioclavicular joint T1 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) 12 9 10 T12 L1 Costal margin Figure 8.27 Sternum • sternum (breastbone) – bony plate anterior to the heart • divided into three regions: – Manubrium – 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 a fatal hemorrhage 8-40 Ribs Copyright © The McGraw-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 8.28b (b) Ribs 2–10 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Superior articular facet Transverse costal facet for rib 6 • 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 Tubercle Superior costal facet for rib 6 Neck T6 (b) Superior view Rib 6 Head Figure 8.29b 8-41 True and False Ribs • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sternoclavicular joint Sternum: Acromioclavicular joint T1 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) 12 9 10 T12 L1 Costal margin Figure 8.27 • 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) • articulate with bodies of vertebrae T11 and T12 • no cartilaginous connection to the sternum or any of the higher costal cartilages 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 – sternoclavicular joint – acromioclavicular joint • scapula articulates with the humerus – glenohumeral joint - shoulder joint – easily dislocated due to loose attachment 8-43 Clavicle Copyright © The McGraw-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 sternal end - rounded head acromial end – flattened braces the shoulder keeping upper limb away from the midline of the body most frequently fractured bone in the body 8-44 Scapula • scapula – named for its resemblance to a spade or shovel • suprascapular notch – conspicuous notch on superior border – provides passage for a nerve • spine – transverse ridge on posterior surface • complex lateral angle of scapula has three main features: – acromion – platelike extension of the spine – coracoid process – shaped like a bent finger – glenoid cavity – shallow socket that articulates with the head of the humerus 8-45 Scapula Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Superior border Suprascapular notch Superior angle Acromion 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 8-46 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 8-47 Humerus • – hemispherical head that articulates with the glenoid cavity of scapula Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Greater tubercle Greater tubercle Head Lesser tubercle Anatomical neck Surgical neck Intertubercular sulcus • Nutrient foramen Deltoid tuberosity proximal end Deltoid tuberosity Figure 8.32 distal end – rounded capitulum articulates with head of radius – trochlea articulates with ulna – lateral and medial epicondyles – olecranon fossa holds olecranon process of ulna – coronoid fossa – radial fossa Coronoid fossa Radial fossa Lateral epicondyle Capitulum Medial supracondylar ridge Medial epicondyle Trochlea (a) Anterior view Lateral supracondylar ridge Lateral epicondyle Olecranon fossa (b) Posterior view 8-48 Radius Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Olecranon 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 Styloid process 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 8-49 Ulna and Interosseous Membrane Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Olecranon Olecranon Trochlear notch • ulna 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 • interosseous membrane Interosseous membrane Ulnar notch of radius Head of ulna Styloid process Styloid process 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 – 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 8-50 Carpal Bones • 8 bones form wrist Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. – allow movements of flexion, extension, abduction and adduction 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 8.34a Trapezoid Trapezium Carpal Capitate bones Scaphoid – proximal row – – scaphoid, lunate, triquetrum, and pisiform • pisiform is a sesamoid developed by age 9 to12 in tendon of flexor carpi ulnaris muscle – distal row trapezium, trapezoid, capitate, and hamate 8-51 Metacarpals and Phalanges Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Distal phalanx II Middle phalanx II Proximal phalanx II IV Head Phalanges Body III metacarpals - bones of the palm – metacarpal I proximal to Key to carpal bones Distal row base of thumb Proximal row – metacarpal V proximal to base of little finger 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 • Trapezoid Trapezium Carpal Capitate bones Scaphoid • phalanges - bones of the fingers – thumb or pollex has two phalanges fingers have three phalanges Figure 8.34a 8-52 • pelvic girdle – consists of a complete ring composed of three bones – two hip (coxal) bones – sacrum that is also part of the vertebral column Pelvic Girdle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. pelvis – bowl-shaped structure composed of the two coxal bones and sacrum supports trunk on the lower limbs and protects viscera, lower colon, urinary bladder, and internal reproductive organs Iliac crest • Iliac fossa • sacroiliac joint - joins hipbone to the vertebral column pubic symphysis – the interpubic disc and adjacent regions of the pubic bone on each side Sacroiliac joint Anterior superior iliac spine Pelvic surface of sacrum Anterior inferior iliac spine Pelvic inlet Spine Coccyx Acetabulum Ischium Body Interpubic disc Ramus Pubis • Base of sacrum Ilium Obturator foramen Superior ramus Inferior ramus Body Pubic symphysis (a) Anterosuperior view Figure 8.35a 8-53 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 – ischium • inferioposterior portion of hip • heavy body with prominent spine – pubis (pubic bone) • most anterior portion of the hip bone Copyright © The McGraw-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 8.36a 8-54 Comparison of Male and Female Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Male Female Pelvic brim Pelvic inlet Obturator foramen Pubic arch 90 120 Figure 8.37 • 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 8-55 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 8-56 Femur • longest and strongest bone of the body • hemispherical head that articulates with the acetabulum of the pelvis – forms ball-and-socket joint – fovea capitis – pit in head of femur for attachment of a ligament • greater and lesser trochanters for muscle attachment • medial and lateral condyles and epicondyles found distally • patellar and popliteal surface Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fovea capitis Greater trochanter 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 8-57 Patella (Kneecap) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fovea capitis Greater trochanter Greater trochanter Head Neck Intertrochanteric crest Intertrochanteric line Lesser trochanter Spiral line Gluteal tuberosity • patella - triangular sesamoid bone embedded in tendon of the knee • cartilaginous at birth – ossifies at 3 to 6 year Linea aspera Shaft • 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 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 8-58 Tibia Copyright © The McGraw-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 Anterior crest Tibia Fibula • tibia - thick, medial, weightbearing bone – only weight bearing bone of the crural region – broad superior head – medial and lateral condyles • fairly flat articular surfaces • articulate with condyle of femur – medial malleolus – bony knob on inside of ankle Distal tibiofibular joint Medial malleolus Lateral malleolus (a) Anterior view Figure 8.39 Lateral malleolus (b) Posterior view 8-59 Fibula Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Intercondylar eminence Medial condyle Lateral condyle Apex Head of fibula Tibial tuberosity Proximal tibiofibular joint • fibula – slender, lateral strut that helps stabilizes ankle • does not bear any body weight Interosseous membrane Lateral surface – spare bone tissue for grafts Anterior crest • head - proximal end Tibia • apex – point of the head Fibula • lateral malleolus - distal expansion, bony knob on lateral side of ankle Distal tibiofibular joint Medial malleolus Lateral malleolus (a) Anterior view Figure 8.39 Lateral malleolus (b) Posterior view • joined to tibia by interosseous membrane 8-60 The Ankle and Foot • • Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Distal phalanx I Distal phalanx V Proximal phalanx I • Middle phalanx V I II – forms heel – distal portion is point of attachment for calcaneal (Achilles) tendon Proximal phalanx V Metatarsal III IV V Medial cuneiform • Intermediate cuneiform Lateral cuneiform Navicular Calcaneus Trochlear surface of talus Key to tarsal bones Distal group Tuberosity of calcaneus Proximal group • (a) Superior (dorsal) view proximal row of tarsal bones – talus, calcaneus, and navicular • Figure 8.40a talus is most superior tarsal bone – forms ankle joint with tibia and fibula – sits upon calcaneus and articulates with navicular Cuboid Talus 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 distal row of tarsal bones – medial, intermediate and lateral cuneiforms and cuboid 8-61 The Foot • remaining bones of foot are similar in name and arrangement to the hand Copyright © The McGraw-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 Proximal phalanx V Metatarsal I II 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 8.40a 8-62 Embryonic Limb Rotation Copyright © The McGraw-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 8-63 anteriorly Foot Arches Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Medial longitudinal arch Transverse arch Lateral longitudinal arch (a) Inferior (plantar) view – 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, • lateral longitudinal arch – from heel to little toe • transverse arch – across middle of foot – arches held together by short, strong ligaments • pes planus (flat feet) – excessive weight, repetitious stress, or congenital weakness Figure 8.42a 8-64 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 8-65 Bipedalism and Limb Adaptations Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) Foot (b) Knee Chimpanzee Human Figure 8.43(1)a,b 8-66 Chimpanzee Human Bipedalism and Upright Stance Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (c) Gluteal muscles Chimpanzee (d) Pelvis (e) Vertebral column Chimpanzee Chimpanzee Human Figure 8.43(1)c Human Figure 8.43(2)d,e Human 8-67 Bipedalism and Head Position Copyright © The McGraw-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 8-68 Human