Chapter 07 Lecture Outline See separate PowerPoint slides for all figures and tables pre-inserted into PowerPoint without notes and animations. 1-1
Chapter 7 Skeletal System Gross Anatomy
7.1 Skeletal System Overview Provides framework Provides levers upon which muscles act to move the body Protection of organs Mineral storage Hemopoiesis Energy storage Components Bones Cartilage Ligaments Tendons 7-3
Skeletal System Overview Terms Body: main part Head: enlarged end Neck: constriction between head and body Margin or border: edge Angle: bend Ramus: branch off body Condyle: smooth rounded articular surface Facet: small flattened articular surface Projections Process: prominent projection Tubercle: small rounded bump Tuberosity: knob Trochanter: tuberosities on proximal femur Epicondyle: near or above condyle 7-4
Skeletal System Overview Ridges Line or linea: low ridge Crest or crista: prominent ridge Spine: very high ridge Openings Foramen: hole Canal or meatus: tunnel Fissure: cleft Sinus or labyrinth: cavity Depressions Fossa: general term for a depression Notch: depression in bone margin Fovea: little pit Groove or sulcus: deeper, narrow depression 7-5
TABLE 7.2 Term Body Head Neck Margin, border Angle Ramus Condyle Facet Ridges Line, linea Crest, crista Spine Projections Process Tubercle Tuberosity, tuber Trochanter Epicondyle Lingula Hamulus Cornu Openings Foramen Canal, meatus Fissure Sinus, labyrinth Depressions Fossa Notch Fovea Groove,ulcus Anatomical Terms for Bone Features Description Main part Enlarged, often rounded end Constriction between head and body Edge Bend Branch off the body beyond the angle Smooth, rounded articular surface Small, flattened aticular surface Low ridge Prominent ridge Very high ridge Prominent projection Small, rounded bump Knob; larger than a tubercle Tuberosity on the proximal femur Upon a condyle Flat, tongue-shaped Hook-shaped Horn-shaped Hole Tunnel Cleft Cavity General term for a depression Depression in the margin of a bone Little pit Deep, narrow depression 7-6
The Complete Skeleton Axial Skeleton Appendicular Skeleton Axial Skeleton Skull Skull Mandible Hyoid bone Mandible Clavicle Scapula Sternum Ribs Humerus Ribs Vertebral column Sacrum Ulna Radius Vertebral column Sacrum Carpal bones Metacarpal bones Phalanges Coxal bone Femur Coccyx Patella Tibia Fibula Tarsal bones Metatarsal bones Phalanges 7-7 Anterior view Posterior view
TABLE 7.1 Number of Named Bones Listed by Category Bones Number Bones Number AxialSkeleton Appendicular Skeleton Skull (Cranium) Braincase (neurocranium) Pectoral Girdle Scapula 2 Paired (left and right) Parietal 2 Clavicle 2 Temporal 2 Upper Limb Unpaired (single) Frontal 1 Humerus 2 Sphenoid Occipital Ethmoid 1 1 1 Ulna Radius Carpal bones 2 2 16 Face (viscerocranium) Metacarpal bones 10 Paired Maxilla Zygomatic 2 2 Phalanges Total girdle and upper limb bones 28 64 Unpaired Palatine Lacrimal Nasal Inferior nasal concha Mandible Vomer Total skull bones 22 2 2 2 2 1 1 Pelvic Girdle Coxal bone Lower Limb Femur Tibia Fibula Patella 2 2 2 2 2 Bones Associated with the Skull Tarsal bones 14 Auditory ossicles Metatarsal bones 10 Malleus 2 Phalanges 28 Incus 2 Total girdle and lower limb bones 62 Stapes Hyoid Vertebral Column Cervical vertebrae Total associated bones 2 1 7 7 Total appendicular skeleton bones Total axial skeleton bones Total appendicular skeleton bones Total bones 126 80 126 206 Thoracic vertebrae 12 Lumbar vertebrae 5 Sacrum 1 Coccyx 1 Total vertebral column bones 26 Rib Cage (Thoracic Cage) Ribs 24 Sternum Total rib cage bones Total axial skeleton bones 1 25 80 7-8
Axial skeleton 7.2 Axial Skeleton Skull Hyoid bone Vertebral column Thoracic (rib) cage 7-9
Sagittal suture Superior View of the Skull Coronal suture Zygomatic arch Superior view Frontal bone Parietal bones Inferior temporal line Superior temporal line Parietal eminence Occipital bone Functions Protects brain Supports organs of special senses Provides foundation for structures that take air, food, and water into body Superior view of skull Parietal bones Frontal bone Sagittal suture Coronal suture 7-10
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Posterior View of Skull Parietal bones Occipital bone Temporal bone Occipitomastoid suture Mastoid Zygom aticarch Posterior view Sagittal suture Lambdoid suture External occipital protuberance Superior nuchal line Inferior nuchal line Occipital condyle Parietal and occipital bones are major structures Lambdoid suture: between parietals and occipital Sutural bones may be present: variable External occipital protuberance Ligamentum nuchae: Helps keep head erect Nuchal lines: Neck muscle attachment points 7-12
Lateral View of Skull Parietal bones and squamous part of temporal bone form most of side of skull Squamous suture: joins the parietal and temporal bone Features of the temporal bone External auditory meatus Mastoid Temporal lines Coronal suture Superior temporal line Inferior temporal line Parietal bone Squamous suture Temporal bone Occipital bone Lambdoid suture Mandibular condyle External auditory canal Occipitomastoid suture Mastoid Zygomatic of the zygomatic arch Greater wing of the sphenoid bone anterior to the temporal bone Zygomatic bones with its temporal of the zygomatic arch Maxilla Mandible. Articulates with the temporal bone. Body, ramus, condyle, and coronoid Styloid Zygomatic arch Zygomatic of temporal bone Temporal of zygomatic bone Mandibular ramus Angle of mandible Body of mandible Lateral view Frontal bone Supraorbital foramen Supraorbital margin Sphenoid bone (greater wing) Nasal bone Lacrimal bone Nasolacrimal canal Infraorbital foramen Zygomatic bone Coronoid of mandible Maxilla Alveolar es Mental foramen Mandible Mental protuberance 7-13
Frontal bone Supraorbital margin Zygomatic arch Nasal bone Zygomatic bone Maxilla Mastoid Mental protuberance Mandible Angle of mandible McGraw-Hill Higher Education, Inc./Eric Wise, photographer 7-14
Anterior View of Skull Frontal bone Coronal suture Glabella Supraorbital margin Temporal bone Parietal bone Supraorbital foramen Optic canal Orbital plate of frontal bone Sphenoid bone (greater wing) Major structures are frontal bone, zygomatic bones, maxillae, and mandible Nasal septum Nasal bone Infraorbital margin Zygomatic bone Perpendicular plate of ethmoid bone Vomer Nasal cavity Maxilla Alveolar es Body of mandible Mental foramen Superior orbital fissure Lacrimal bone Infraorbital foramen Middle nasal concha Inferior nasal concha Anterior nasal spine Oblique line of mandible Mandible Mandibular symphysis Maxilla and mandible bear teeth Orbits. Cone-shaped fossae with their apices oriented posteriorly Anterior view Mental protuberance Nasolacrimal canal Optic foramen 7-15
Glabella Frontal bone Supraorbital margin Zygomatic bone Maxilla Mandible Mental protuberance McGraw-Hill Higher Education, Inc./Eric Wise, photographer 7-16
The Orbit Supraorbital foramen Frontal bone Superior orbital fissure Sphenoid bone Palatine bone Zygomatic bone Lesser wing Greater wing Optic canal Posterior and anterior ethmoidal for amina Ethmoid bone Lacrimal bone Opening to nasolacrimal canal Maxilla Inferior orbital fissure Infraorbital foramen Infraorbital groove Anterior view 7-17
Bones of Nasal Cavity Nasal septum Frontal bone Frontal sinus Nasal bone Perpendicular plate of ethmoid bone Septal cartilage Vomer Greater alar cartilage Anterior nasal spine Central incisor Frontal bone Frontal sinus Nasal bone Maxilla bone Lateral nasal cartilage Greater alar cartilage Lateral incisor (a) Medial view (b) Medial view Crista galli Horizontal plate of palatine bone Palatine of maxilla Incisive canal Cribriform plate Olfactory foramina Sphenoidal sinus Sphenoid bone Hard palate Lacrimal bone Olfactory recess Superior nasal concha Middle nasal concha Sphenoidal sinus Sphenoid bone Inferior nasal concha Vertical plate Horizontal plate Medial pterygoid plate Part of ethmoid bone Palatine bone Palatine of maxilla Nasal cavity. Pear-shaped, open anteriorly Nasal septum divides nasal cavity into right and left halves Bony part is vomer and perpendicular plate of the ethmoid Hyaline cartilage anterior part Nasal conchae: form lateral walls Inferior: separate bones Middle and superior: projections of the ethmoid Increase surface of nasal cavity 7-18
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Paranasal Sinuses Associated with the bones of the nasal cavity Functions Decrease skull weight Resonating chambers Named for bones in which they are found Frontal Maxillary Ethmoidal Sphenoidal Frontal sinus Sphenoidal sinus Ethmoidal labyrinth (sinuses) Maxillary sinus (b) Frontal sinus Ethmoidal labyrinth (sinuses) Sphenoidal sinus (c) Maxillary sinus (d) (a) c-d: Jupiter Media/Alamy 7-20
Interior of the Cranial Cavity Cranial cavity: occupied by the brain Floor divided into anterior, middle, and posterior fossae Crista galli: prominent ridge in center of anterior fossa. Point of attachment for the dura mater (one of the meninges) Olfactory fossae lateral to crista galli. Olfactory bulb within Cribriform plate of the ethmoid forms floor of olfactory fossae Olfactory nerves pass through the foramina of the cribriform plate Sella turcica: part of sphenoid bone that houses the pituitary gland Foramen magnum: opening where brain attaches to spinal cord 7-21
Interior of the Cranial Cavity Frontal sinuses Anterior cranial fossa Crista galli Olfactory foramina Cribriform plate Frontal bone Ethmoid bone Sphenoid bone Temporal bone Lesser wing Greater wing Middle cranial fossa Squamous portion Petrous portion Optic canal Sella turcica Foramen rotundum Foramen ovale Foramen spinosum Carotid canal (foramen lacerum is inferior) Hypoglossal canal Foramen magnum Parietal bone Occipital bone Internal auditory canal Jugular foramen Posterior cranial fossa Superior view 7-22
Inferior View of Skull Foramina Foramen magnum: spinal cord exits and vertebral arteries enter Carotid canals: internal carotid arteries Foramen lacerum: internal carotid Jugular foramen: internal jugular veins Specialized surfaces Occipital condyles: articulation between skull and vertebral column Styloid es: attachment site for muscles that move the tongue Mandibular fossa: site of articulation with mandibular condyles Medial and later pterygoid plates: parts of sphenoid bone that surround posterior opening of nasal cavities Vomer: posterior portion of nasal septum Hard palate: floor of the nasal cavity. With the soft palate, separates nasal from oral cavities 7-23
Inferior View of Skull Incisive fossa Maxilla Zygomatic bone Palatine of maxillary bone Horizontal plate of palatine bone Hard palate Sphenoid bone Anterior palatine foramen Posterior palatine foramen Inferior orbital fissure Lateral pterygoid plate Greater wing Medial pterygoid plate Foramen ovale Foramen spinosum External auditory canal Jugular foramen Occipital condyle Foramen magnum Pterygoid hamulus Temporal of zygomatic bone Zygomatic arch Zygomatic of temporal bone Vomer Foramen lacerum Styloid Mandibular fossa Carotid canal (posteroinferior opening) Stylomastoid foramen Mastoid Temporal bone Occipital bone Inferior nuchal line External occipital protuberance Superior nuchal line Inferior view 7-24
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Bones of the Skull Twenty-two bones plus six auditory ossicles that function in hearing Of the twenty-two, two portions- Braincase (Neurocranium) Surrounds and protects brain Parietals, temporals, frontal, occipital, sphenoid, ethmoid Facial bones (Viscerocranium) Protect major sensory organs- eyes, nose, and tongue Provide attachment sites for muscles of mastication, facial expression, and eye movement Maxilla and mandible have alveolar es and sockets for tooth attachment Maxillae, zygomatics, palatines, lacrimals, nasals, inferior nasal conchae, mandible, vomer. Note: frontal and ethmoid contribute to the face and mandible is not part of the skull 7-26
TABLE 7.7 Skull Bones (a) Parietal Bone (Right) Lateral View Landmark Parietal eminence Superior and inferior temporallines Special Feature Forms lateral wall of skull Description The widest part of the head is from one parietal eminence to the other. Attachment point for temporalis muscle Parietal eminence Superior tem poralline Inferior temporal line 7-27
TABLE 7.7 Skull Bones (b) Temporal Bone (Right) Lateral and Medial Views Landmark Carotid canal (shownin figures 7.11 and 7.12 ) Description Canal through which the internal carotid artery enters the cranial cavity External auditory canal External canal of the ear; carries sound to the ear Squamous portion Internal auditory canal (shown in figure 7.11 ) Opening through which the facial (cranial nerve VII) and vestibulocochlear (cranial nerve VIII) nerves enter the petrous portion of the temporal bone Mastoid Zygomatic Mandibular fossa External auditory canal Forms one side of jugular for a men (shown in figures 7.11 and 7.12 ) Mandibular fossa Foramen through which the internal jugular vein exits the cranial cavity Articulation point between the mandible and skull Styloid Mastoid Attachment point for muscles moving the head and for a hyoid muscle Lateral view Middle cranial fossa (shown in figure 7.11) Depression in the floor of the cranial cavity formed by the temporall obesof the brain Petrous portion (shown in figure 7.11) Thick portion of the temporal bone Squamous portion (shown in figure 7.11 ) Flat, lateral portion of the temporal bone Mastoid Medial view Squamous portion Petrous portion Internal auditory canal Styloid Styloid Stylomastoid foramen (shown infigure 7.12 ) Zygomatic Attachment for muscles of the tongue, throat, and hyoid bone Foramen through which the facial nerve (cranial nerve VII ) exits the skull Helps form the bony bridge extending from the cheek to just anterior to the ear; attachment for a muscle that moves the mandible Special Features Contains the middle and inner ear and the mastoid air cells Place where the mandible articulates with the rest of the skull 7-28
TABLE 7.7 Skull Bones Continued (c) Frontal Bone Anterior View Landmark Glabella Nasal spine Orbital plate Supraorbital foramenar Supraorbital margin Zygomatic Description Area between the supraorbital margins Superior part of the nasal bridge Roof of the orbit Opening through which nerves and vessels exit the skull to the skin of the forehead Ridge forming the anterior superior border of the orbit Connects to the zygomatic bone; helps form the lateral margin of the orbit Glabella Supraorbital foramen Orbital plate Supraorbital margin Zygomatic Nasal spine Special Features Forms the forehead and roof of the orbit Contains the frontal sinus 7-29
TABLE 7.7 Skull Bones Continued (d) Sphenoid Bone Superior and Posterior Views Landmark Description Body Thickest part of the bone; articulates with the occipital bone Foramen ovale Opening through which a branch of the trigeminal nerve (cranial nerve V) exits the cranial cavity Optic canal Foramen rotundum Opening through which a branch of the trigeminal nerve (cranial nerve V) exits the cranial cavity Lesser wing Greater wing Superior orbital fissure Sella turcica Foramen spinosum Greater wing Opening through which a major artery to the meninges (membranes around the brain) enters the cranial cavity Forms the fl oor of the middle cranial fossa; several foramina pass through this wing Foramen rotundum Foramen ovale Foramen spinosum Superior view Groove of carotid canal Lateral pterygoid plate Attachment point for muscles of mastication (chewing) Lesser wing Superior border of the superior orbital fissure Medial pterygoid plate Posterolateral walls of the nasal cavity Lesser wing Greater wing Superior orbital fissure Body Optic canal Pterygoid canal Pterygoid hamulus Opening through which the optic nerve (cranial nerve II) passes from the orbit to the cranial cavity Opening through which nerves and vessels exit the cranial cavity Process around which the tendon passes from a muscle to the soft palate Sella turcica Fossa containing the pituitary gland Foramen rotundum Pterygoid canal Pterygoid hamulus Posterior view Lateral pterygoid plate Medial pterygoid plate Superior orbital fissure Special Feature Contains the sphenoidal sinus Opening through which nerves and vessels enter the orbit from the cranial cavity 7-30
TABLE 7.7 Skull Bones Continued (e) Occipital Bone Inferior View Landmark Condyle Description Articulation point between the skull and first vertebra External occipital protuberance Attachment point for a strong ligament (nuchal ligament) in the back of the neck Anterior Condyle Foramen magnum Foramen magnum Hypoglossal canal (shown in figure 7.11) Inferior nuchal line Posterior cranial fossa (shown in figure 7.11) Superior nuchal line Opening around the point where the brain and spinal cord connect Opening through which the hypoglossal nerve (cranial nerve XII) passes Attachment point for neck muscles Depression in the posterior of the cranial cavity formed by the cerebellum Attachment point for neck muscles Special Feature Inferior nuchalline Forms the base of the skull Superior nuchalline Posterior External occipital protuberance 7-31
TABLE 7.7 Skull Bones Continued (f) Zygomatic Bone (Right) Lateral View Frontal Landmark Frontal Infraorbital margin Temporal Zygomaticofacial foramen Description Connection to the frontal bone; helps form the lateral margin of the orbit Ridge forming the inferior border of the orbit Helps form the bony bridge from the cheek to just anterior to the ear Opening through which a nerve and vessels exit the orbit to the face Temporal Zygomaticofacial foramen Infraorbital margin Maxillary Special Features Forms the prominence of the cheek Forms the anterolateral wall of the orbit 7-32
TABLE 7.7 Skull Bones Continued (g) Ethmoid Bone Superior, Lateral, and Anterior Views Land mark Description Cribriformplate Contains numerous olfactory foramina through which branches of the olfactory nerve (cranial nerve I) enter the cranial cavity from the nasal cavity Anterior Perpendicular plate Cristagalli Ethmoidalforamina (shown in figure7.8) Attachment for meninges (membranes around brain) Openings through which nerves and vessels pass from the orbit to the nasal cavity Crista galli Ethmoidal labyrinth (sinuses) Middle nasal concha Ridge extending into the nasal cavity; increases surface area, helps warm and moisten air in the cavity Cribriform plate Orbital plate Perpendicular plate Forms the medial wall of the orbit Forms the superior portion of the nasal septum Orbital plate Superior nasal concha Ridge extending into the nasal cavity; increases surface area, helps warm and moisten air in the cavity Posterior Special Features Forms part of the nasal septum and part of the lateral walls and roof of the nasal cavity Superior view Contains the ethmoidal labyrinth, or ethmoidal sinuses; the labyrinth is divided into anterior, middle, and posterior ethmoidal cells Crista galli Orbital plate Ethmoidal labyrinth (sinuses) Posterior Anterior Middle nasal concha Perpendicular plate Lateral view Crista galli Orbital plate Ethmoidal labyrinth (sinuses) Perpendicular plate Superior nasal concha Middle nasal concha Anterior view 7-33
TABLE 7.7 Skull Bones Continued (h) Maxilla (Right) Medial and Lateral Views Frontal Maxillary sinus Palatine Incisive canal Alveolar Landmark Alveolar Anterior nasal spine Frontal Incisive canal Infraorbital foramen Orbital surface Palatine Maxillary Tuberosity Zygomatic Description Ridge containing the teeth Forms part of the nasal septum Forms the sides of the nasal bridge Opening through which a nerve exits the nasal cavity to the roof of the oral cavity Opening through which a nerve and vessels exit the orbit to the face Forms the fl oor of the orbit Forms the anterior two-thirds of the hard palate Lump posterior to the last maxillary molar tooth Connection to the zygomatic bone; helps form the interior margin of the orbit Special Features Contains the maxillary sinus and maxillary teeth Forms part of nasolacrimal canal Molars Premolars Canine Incisors Medial view Notch for lacrimal bone Frontal Orbital surface Zygomatic Tuberosity Infraorbital foramen Anterior nasal spine Alveolar Lateral view Incisors Canine Premolars Molars 7-34
TABLE 7.7 Skull Bones Continued (i) Palatine Bone (Right) Medial and Anterior Views Landmark Horizontal plate Vertical plate Description Forms the posterior one-third of the hard palate Forms part of the lateral nasal wall Special Feature Helps form part of the hard palate and a small part of the wall of the orbit Vertical plate Vertical plate Horizontal plate Horizontal plate Medial view Anterior view 7-35
TABLE 7.7 Skull Bones Continued (j) Lacrimal Bone (Right) Anterolateral View Special Features Forms a small portion of the orbital wall Forms part of the nasolacrimal canal Lacrimal bone Nasolacrimal canal 7-36
TABLE 7.7 Skull Bones Continued (k) Nasal Bone (Right) Anterolateral View Special Feature Forms the bridge of the nose Nasal bone 7-37
TABLE 7.7 Skull Bones Continued (l) Mandible (Right Half) Medial and Lateral Views Landmark Alveolar Angle Description Ridge containing the teeth Corner between the body and ramus Molars Premolars Canine Incisors Body Mandibular notch Mandibular condyle Condylar Medial view Coronoid Mandibular notch Mandibular condyle (head) Condylar Ramus Mandibular foramen Lingula Alveolar Mylohyoid line Angle Coronoid Molars Premolars Canine Body Condylar Coronoid Mandibular condyle Mandibular foramen Mandibular notch Mental foramen Mylohyoid line Oblique line Ramus Major, horizontal portion of the bone Extension containing the mandibular condyle Attachment for a muscle of mastication Helps form the temporomandibular joint (the point of articulation between the mandible and the rest of the skull) Opening through which nerves and vessels to the mandibular teeth enter the bone Depression between the condylar and the coronoid Opening through which a nerve and vessels exit the mandible to the skin of the chin Attachment point of the mylohyoid muscle Ridge from the anterior edge of the ramus onto the body of the mandible Major, nearly vertical portion of the bone Oblique line Ramus Body Angle Lateral view Incisors Alveolar Mental foramen Special Features The only bone in the skull that is freely movable relative to the rest of the skull bones Holds the lower teeth 7-38
TABLE 7.7 Skull Bones Continued (m) Vomer Anterior and Lateral Views Alae Alae Landmark Alae Vertical plate Description Attachment points between the vomer and sphenoid Forms part of the nasal septum Special Feature Forms most of the posterior and inferior portions of the nasal septum Vertical plate Vertical plate Anterior view Lateral view 7-39
Hyoid Bone TABLE 7.8 Hyoid Bone Anterior and Lateral Views Greater cornu Landmark Body Greater cornu Lesser cornu Special Features Description Major portion of the bone Attachment point for muscles and ligaments Attachment point for muscles and ligaments One of the few bones of the body that does not articulate with another bone Attached to the skull by muscles and ligaments Lesser cornu Body Anterior view Lesser cornu Greater cornu Lateral view Body 7-40
Vertebral Column Functions Supports weight of head and trunk Protects the spinal cord Allows spinal nerves to exit the spinal cord Provides site for muscle attachment Permits movement of head and trunk Twenty-six bones in adult; 33-34 in embryo 5 fuse to form sacrum 4 or 5 coccygeal fuse to form the coccyx Regions Cervical (7 vertebrae) Thoracic (12 vertebrae) Lumbar (5 vertebrae) Sacral bone (1) Coccygeal bone (1) 7-41
Vertebral Column Cervical region (convex anteriorly) Thoracic region (concave anteriorly) Lumbar region (convex anteriorly) Sacral and coccygeal regions (concave anteriorly) L a te r al view First cervical vertebra (atlas) Second cervical vertebra (axis) Coccyx Seventh cervical vertebra First thoracic vertebra Sacrum Intervertebral foramina Body Intervertebral disk Twelfth thoracic vertebra First lumbar vertebra Transverse Spinous Fifth lumbar vertebra Sacral promontory Four major curvatures in adults Cervical: anterior Thoracic: posterior Lumbar: anterior Sacral and coccygeal: posterior At birth, column is C shaped When head is raised, cervical curve appears When sitting and walking begin, lumbar curve develops Abnormal curvatures Lordosis. Exaggeration of lumbar Kyphosis. Exaggeration of thoracic Scoliosis. Lateral, often accompanied by kyphosis 7-42
General Features of the Vertebrae TABLE 7.9 Feature Body Vertebral foramen Vertebral arch Pedicle Lamina Transverse Spinous Articular es General Structure of a Vertebra Description Disk-shaped; usually the largest part with fl at surfaces directed superiorly and inferiorly; forms the anterior wall of the vertebral foramen; intervertebral disks are located between the bodies Hole in each vertebra through which the spinal cord passes; adjacent vertebral foramina form the vertebral canal Forms the lateral and posterior walls of the vertebral foramen; possesses several es and articular surfaces Foot of the arch with one on each side; forms the lateral walls of the vertebral foramen Posterior part of the arch; forms the posterior wall of the vertebral foramen Process projecting laterally from the junction of the lamina and pedicle; a site of muscle attachment Process projecting posteriorly at the point where the two laminae join; a site of muscle attachment; strengthens the vertebral column and allows for movement Superior and inferior projections containing articular facets where vertebrae articulate with each other; strengthen the vertebral column and allow for movement Intervertebral notches Form intervertebral foramina between two adjacent vertebrae through which spinal nerves exit the vertebral canal 7-43
General Features of the Vertebrae TABLE 7.9 General Structure of a Vertebra Transverse Spinous Lamina Body (cut) Part of vertebral canal Superior articular facet Superior articular Pedicle Vertebral arch Intervertebral disk Vertebral foramen Body Vertebral foramina Spinous (cut) ( a ) Superior view ( b ) Lateral view, Sagittal section Anterior Posterior Superior articular Anterior Posterior Transverse Pedicle Inferior articular of superior vertebra Superior articular of inferior vertebra Space for intervertebral disk Inferior intervertebral notch of superior vertebra Superior intervertebral notch of inferior vertebra Intervertebral foramen Body Spinous es ( c ) ( d ) 7-44
Spina Bifida Lamina of vertebrae: can be removed (laminectomy) when they inhibit a surgery such as a disc removal. Spina bifida: failure of the laminae to form or to fuse together during development. Can affect the spinal cord. Most often occurs in lumbar region. Posterior Dura mater Skin of back Enlarged fluid-filled space Spinal cord Cauda equina Body of first lumbar vertebra Back muscles Incomplete vertebral arch Superior view 7-45
Intervertebral Disks Intervertebral disk Vertebral body Annulus fibrosus Nucleus pulposus Intervertebral foramen Annulus fibrosus Nucleus pulposus (a) Lateral view (b) Superior view Located between adjacent vertebrae Functions Provide support Prevent vertebrae rubbing against each other Consist of Annulus fibrosus: external Nucleus pulposus: internal and gelatinous Becomes compressed with age and height decreases With age, more susceptible to herniation 7-46
Herniated or Ruptured Disk Part of the fibrosus has been removed to expose the pulposus. Breakage or ballooning of the annulus fibrosus with a partial or complete release of the nucleus pulposus. May push against spinal nerves impairing function and causing pain. Spinous Transverse Spinal cord in vertebral canal Compressed spinal nerve root in intervertebral foramen Herniated portion of disk Nucleus pulposus Annulus fibrosus Intervertebral disk Superior view 7-47
TABLE 7.10 Comparison of Vertebral Regions Feature Cervical Thoracic Lumbar Superior articular facet Transverse Body Body Body Transverse foramen Inferior articular facet Superior articular Facets for rib Transverse articulation Spinous Spinous Inferior articular facet Superior articular Transverse Spinous Body Absent in C1, small in others Medium-sized with articular facets for ribs Large Transverse Transverse foramen Articular facets for ribs, except T11 and T12 Square Spinous Absent in C1, bifid in others, except C7 Long, angled inferiorly Square Articular facets Face superior/inferior Face obliquely Face medial/lateral 7-48
Cervical Vertebrae Superior seven vertebrae Have very small bodies, tend to have bifid spinous es, and have transverse foramina Atlas: first cervical vertebra Articulates with skull and allows yes movement No body and no spinous Axis: second cervical vertebra Dens or odontoid extends superiorly into the vertebral foramen of the atlas Allows rotation of the atlas on the axis, the no movement Vertebral prominence: most prominent spinous in area. Usually 7 th cervical Superior articular facets face superiorly; inferior facets face inferiorly 7-49
Transverse Transverse foramen Posterior arch Vertebral foramen Superior articular facet (articulates with occipital condyle) Facet for dens Anterior arch (a) Atlas (first cervical vertebra), superior view Anterior arch Superior articular facet Transverse (b) Atlas, lateral view Posterior arch Transverse Transverse foramen Dens Body Spinous (bifid) Posterior arch Vertebral foramen Superior articular facet Dens Superior articular facet Body Spinous Transverse foramen (c) Axis (second cervical vertebra), superior view (d) Axis, lateral view Anterior arch Transverse ligament Dens of axis Atlas Posterior arch Axis Lamina Pedicle Transverse foramen Transverse Body Spinous (bifid) Vertebral foramen Superior articular facet (e) Atlas and axis articulated, superior view (f) Fifth cervical vertebra, superior view Vertebral body Superior articular Transverse Spinous Bifid tip of spinous Inferior articular Transverse foramen Inferior articular facet (g) Fifth cervical vertebra, lateral view (h) Trent Stephens Dens Body C1 C2 C3 C4 C5 C6 C7 (h) Anterolateral view Spinous es Transverse Transverse foramen 7-50
Thoracic Vertebrae Anterior Lamina Transverse Body Superior articular Pedicle Superior intervertebral notch Superior articular facet for rib head Inferior articular facet for rib head Inferior intervertebral notch Body (a) Superior view (b) Lateral view Spinous Vertebral foramen Articular facet for tubercle of rib Superior articular facet Superior articular facet for rib head Superior articular Superior articular facet Pedicle Transverse Articular facet for tube rcle of rib Lamina Inferior articular Spinous Body Space for intervertebral disk T1 T2 T3 T4 T5 T6 T7 Posterior Articular facet for rib head Articular facet for tubercle of rib Transverse Spinous Intervertebral foramen Long, thin spinous es directed inferiorly Long transverse es Articular facets on transverse es for ribs (first 10 thoracic vertebrae) Facets on body for articulation with ribs Most ribs have heads that articulate with two sequential vertebrae (c) Posterolateral view (c) Trent Stephens 7-51
Lumbar Vertebrae Spinous Lamina Large thick bodies Transverse Pedicle Superior articular facet Vertebral foramen Heavy rectangular transverse and spinous es Body Superior articular facets face medially; inferior articular facets face laterally Vertebral body Pedicle (a) Superior view Superior articular Transverse Spinous Adds strength Inferior articular Inferior articular facet Limits rotation (b) Lateral view L1 Intervertebral foramen Body L2 Spinous Space for intervertebral disk L3 L4 Transverse L5 (c) Lateral view (c) Trent Stephens 7-52
Sacrum and Coccyx Ala Sacr al promontory Anterior sacral for amina Transverse lines Ala Sacral canal Auricular surface (articulates with coxal bone) Posterior sacral foramina (a) Anterior view Coccyx Superior articular facet (articulates with fifth lumbar vertebra) Median sacral crest Sacral hiatus Sacrum Alae: superior lateral parts of fused transverse es Auricular surface: articulates with pelvic bone Median sacral crest: partially fused spinous es Sacral hiatus: site of anesthesia injection Sacral foramina: intervertebral foramina Sacral promontory: anterior edge of body of first vertebra. Marks separation of abdominal and pelvic cavities Coccyx: tailbone Coccyx (b) Posterior view 7-53
Rib Cage Sternal end True ribs False ribs (8 12) Clavicle Sternal angle Costal cartilage Floating ribs Head Neck Tubercle 9 7 8 10 6 5 4 3 Angle Body (b) Inferior view 2 1 11 T12 12 L1 (a) Anterior view Articular facet for transverse of vertebra (c) Lateral view (c) Trent Stephens Seventh cervical vertebra First thoracic vertebra Jugular notch Manubrium Body Xiphoid Sternum Head of rib set against the inferior articular facet of the superior vertebra Head of rib set against the superior articular facet of the inferior vertebra Tubercle of rib set against the articular facet on the transverse of the inferior vertebra Angle of rib Body of rib Functions Protects vital organs Forms semi-rigid chamber for respiration Parts Thoracic vertebrae Ribs (12 pair) True or Vertebrosternal: superior seven. Attach directly to sternum via costal cartilages False: inferior five Vertebrochondral (3) joined by common cartilage to sternum Floating or vertebral (2) do not attach to sternum 7-54
Manubrium Sternum Articulates with first rib and clavicle Jugular notch superiorly Sternal angle: point where manubrium joins body. Second rib articulates here Body: third through seventh ribs articulate Also called gladiolus Xiphoid : inferior tip Clavicle 1 Seventh cervical vertebra First thoracic vertebra Jugular notch True ribs Sternal angle Costal cartilage 4 5 3 2 Manubrium 6 7 Body Xiphoid Sternum False ribs (8 12) Floating ribs 9 8 10 11 T12 12 L1 7-55 (a) Anterior view
7.3 Appendicular Skeleton Girdles Pectoral or shoulder Pelvic Upper Limbs Arm Forearm Wrist Hand Lower Limbs Thigh Leg Foot Ulna Radius Anterior view Carpal bones Metacarpal bones Phalanges Clavicle Scapula Humerus Pectoral girdle Upper limb Anterior view Sacrum Coxal bone Femur Patella Tibia Fibula Tarsal bones Metatarsal bones Phalanges Pelvic girdle Lower limb 7-56
Pectoral Girdle Scapula (2) Acromion Forms protective cover Attachment for clavicle Attachment for muscles Scapular spine: divides posterior surface into supraand infraspinous fossae Coracoid : attachment for muscles Glenoid cavity: articulates with humerus Clavicle (2): articulates with acromion and with manubrium of sternum Acromion Coracoid Supraglenoid tubercle Glenoid cavity Infraglenoid tubercle Lateral (axillary) border Inferior angle Acromial (lateral) end (a) Anterior view Body of clavicle (c) Superior view Superior angle Superior border Scapular notch Supraspinous fossa Scapular spine Subscapular fossa Medial (vertebral) border View in (d) Sternal (medial) end d: Trent Stephens Spine of scapula Supraspinous fossa of scapula Superior border of scapula Acromion of scapula Acromial end of clavicle Coracoid of scapula Body of clavicle Acromion Coracoid Glenoid cavity Infraglenoid tubercle Infraspinous fossa Lateral (axillary) border (b) Posterior view Posterior Anterior (d) Superior view 7-57
Arm (Humerus) Greater tubercle Lesser tubercle Intertubercular groove Deltoid tuberosity Lateral supracondylar ridge Radial fossa Lateral epicondyle Capitulum Head Anatomical neck Surgical neck Medial supracondylar ridge Coronoid fossa Medial epicondyle Radial groove Olecranon fossa Lateral epicondyle Head Neck: anatomic and surgical Tubercles: greater and lesser Intertubercular groove Deltoid tuberosity Capitulum: rounded, articulates with radius Trochlea: spool-shaped, articulates with ulna Epicondyles Trochlea Trochlea (a) Anterior view (b) Posterior view 7-58
Forearm: Radius Radial notch of ulna Olecranon View in (a) Head of radius Radial notch of ulna Head Neck Radial tuberosity Interosseous ridges Radius (a) Proximal view Trochlear notch Coronoid Trochlear notch Coronoid Radial notch of ulna Ulnar tuberosity Ulna Olecranon Medial: thumb side Proximal end Head rotates in radial notch of ulna. Radial tuberosity: site of biceps brachii insertion Distal end Articulates with carpals and ulna Styloid Head Styloid (b) Anterior view Styloid Ulnar notch of radius (c) Medial view of ulna 7-59
Forearm: Ulna Lateral: little finger side Proximal end View in (a) Radial notch of ulna Head of radius (a) Proximal view Olecranon Trochlear notch Coronoid Trochlear notch: fits over trochlea of humerus Olecranon : point of elbow Radial notch of ulna Head Neck Radial tuberosity Trochlear notch Coronoid Radial notch of ulna Ulnar tuberosity Olecranon Coronoid Distal end Interosseous ridges Ulna Head articulates with radius and with carpals Radius Styloid Head Styloid (b) Anterior view Styloid Ulnar notch of radius (c) Medial view of ulna 7-60
Heads of metacarpal bones (knuckles) Head of ulna Acromion Lateral epicondyle Olecranon Medial border of scapula Olecranon Medial epicondyle The McGraw-Hill Companies, Inc./Eric Wise, photographer 7-61
Wrist and Hand Wrist: eight carpal bones In order from lateral to medial for proximal row and medial to lateral for distal row: So Long Top Part, Here Comes The Thumb Scaphoid, Lunate, Triquetrum, Pisiform, Hamate, Capitate, Trapezoid, Trapezium As a unit are convex posteriorly and concave anteriorly Carpal tunnel: on anterior surface. Ligament from tubercle of trapezium to hook of hamate Hand: five metacarpals (palm of hand); five digits with their phalanges 7-62
Wrist and Hand Radius Ulna Carpal bones (distal row) Carpal bones (proximal row) Scaphoid bone Lunate bone Triquetrum bone Pisiform bone Hamate bone Capitate bone Trapezoid bone Trapezium bone Scaphoid bone Lunate bone Triquetrum bone Pisiform bone Carpal bones (proximal row) Metacarpal bones 5 4 3 2 1 1 2 3 4 5 Proximal phalanx of thumb Distal phalanx of thumb Digits Proximal phalanx of finger Middle phalanx of finger Distal phalanx of finger (a) Posterior view (b) Anterior view 7-63
Pelvic Girdle Sacrum Sacroiliac joint Anterior superior iliac spine Acetabulum Symphysis pubis Obturator foramen Subpubic angle Anterosuperior view Sacral promontory Ilium Pubis Ischium Coxal bone Coxal bones and sacrum form ring Pelvis: pelvic girdle and coccyx Coxal bones: Right and Left Ilium Ischium Pubis Acetabulum: articulates with head of femur Obturator foramen Sacrum 7-64
Sacrum Coxal bone Pelvic girdle Femur Patella Tibia Lower limb Fibula Anterior view Tarsal bones Metatarsal bones Phalanges 7-65
Coxal Bones Formed as fusion of embryonic ilium, ischium, pubis. All three contribute to acetabulum Ilium: iliac crest, anterior and posterior superior iliac spines, greater sciatic notch, auricular surface, sacroiliac joint, iliac fossa Ischium: ischial tuberosity Pubis: pubic crest, symphysis pubis (pubic symphysis) Pelvic brim False (greater pelvis) pelvis superior to brim True pelvis inferior to brim Pelvic inlet Pelvic outlet 7-66
Coxal Bones Ilium Acetabulum Cartilage in young pelvis Pubis Ischium Obturator foramen (a) Lateral view Tubercle of iliac crest Posterior superior Iliac spine Posterior inferior iliac spine Greater sciatic notch Ischial spine Lesser sciatic notch Ischial tuberosity Lunate surface Acetabulum Iliac crest Ilium Iliac fossa Anterior superior iliac spine Anterior inferior iliac spine Linea terminalis Superior pubic ramus Pubis Acetabular notch Pubic tubercle Pubic crest Inferior pubic ramus Obturator foramen Arcuate line Pectineal line Auricular surface (articulates with sacrum) Posterior superior iliac spine Posterior inferior iliac spine Greater sciatic notch Ischium Ischial spine Lesser sciatic notch Ischial ramus 7-67 (b) Lateral view Ischial ramus (c) Medial view
Comparison of the Male and Female Pelvis Pelvic Inlet (red dashed line) Sacral promontory Pelvic brim Symphysis pubis Subpubic angle Ischial spine Coccyx Symphysis pubis Pelvic outlet (blue dashed line) Male (a) Anterosuperior view Female (b) Anterosuperior view Pelvic brim Sacral promontory Pelvic inlet (c) Medial view Coccyx Pelvic outlet 7-68
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Thigh Femur Head: articulates with acetabulum Neck Trochanters: attachment for muscles that fasten lower extremity to hip Greater and lesser Distal condyles: articulate with tibia Medial and lateral Epicondyles: ligament attachment Medial and lateral Patella or kneecap: sesamoid In tendon of quadriceps femoris Changes force relationship between femur and tibia 7-70
Thigh Head Greater trochanter Neck Intertrochanteric line Fovea capitis Lesser trochanter Head Greater trochanter Neck Intertrochanteric crest Pectineal line Gluteal tuberosity Linea aspera Body (shaft) of femur Adductor tubercle Medial epicondyle Lateral epicondyle Lateral epicondyle Intercondylar fossa Patellar groove Medial condyle Lateral condyle 7-71 (a) Anterior view (b) Posterior view
Anterior surface (a) Anterior view Posterior surface Medial facet Lateral facet (b) Posterior view 7-72
Leg Intercondylar eminence Lateral condyle Apex Head Proximal articulation of tibia and fibula Distal articulation of tibia and fibula Lateral malleolus Fibula Anterior view Medial condyle Tibial tuberosity Anterior crest Tibia Medial malleolus Tibia Larger and supports most of weight Tibial tuberosity: attachment of quadriceps femoris Anterior crest: shin Condyles: medial and lateral; articulate with condyles of femur Intercondylar eminence Medial malleolus: medial side of ankle Fibula Articulates with tibia not femur Lateral malleolus: lateral wall of ankle 7-73
Foot: Tarsals, Metatarsals, Phalanges Digits Metatarsal bones Proximal phalanx Middle phalanx Distal phalanx Talus Navicular Intermediate cuneiform Medial cuneiform 5 4 3 2 1 (a) Superior view Calcaneus Talus Cuboid Navicular Medial cuneiform Intermediate cuneiform Lateral cuneiform Proximal phalanx of great toe Distal phalanx of great toe Tarsal bones Fibula Tibia Tarsals (7) Proximal row: No Thanks Cow = Navicular, Talus, Calcaneus Distal row: MILC = Medial, Intermediate and Lateral Cuneiforms Metatarsals (5): foot Phalanges: toes Medial longitudinal arch Talus Lateral longitudinal arch Transverse arch Cuboid Calcaneus Phalanges Metatarsal bones (b) Medial inferior view Tarsal bones 7-74
Function Arches of the Foot Distribute weight of body between heel and ball of foot: weight transferred from the tibia and fibula to the talus. From there, the weight is distributed first to the calcaneus then through the arch system along the lateral side of the foot to the ball (head of the metatarsals). Footprint in wet sand: only heel, lateral margin, ball, and toes of foot imprinted. Three major arches Transverse arch Longitudinal arches: Medial and lateral 7-75