3.2 Skeletal System PDF

Objectives Overview of the Skeleton Surface Features of Bones Axial and Appendicular Skeleton The Skull THE SKELETAL SYSTEM...

Objectives Overview of the Skeleton Surface Features of Bones Axial and Appendicular Skeleton The Skull THE SKELETAL SYSTEM Pectoral DR AISHA MOHD DIN rounded knob girdle Axial skeleton in Contains: Features of the skull Regions of the skeleton 1 narrow puncal" tan neurocranium Neurocranium Features of the vertebral – axial skeleton = central axis area for attachment/articulation – skull, vertebrae, (Cranial vault) column and thoracic cage skull, vertebral column, ribs, sternum and sacrum sternum, ribs, hole sacrum and hyoid THE SKULL a Features of the pectoral girdle – appendicular skeleton = limbs and girdles basin Appendicular Viscerocranium 3 2. and upper limb bones Number of bones pelvic girdle skeleton in green (facial skeleton) hip bane Features of the pelvic girdle – start at 270 at birth, decreases with fusion Bone projected out - ischium – pectoral girdle viscerocranium illium – 206 in typical adult skeleton – upper extremity - and lower limb bones "Space" carity of bone - publis Sharap , narrow process – pelvic girdle – lower extremity - -  lesser Sphenoid bone wing · single bonsees ↑ Roof : Calvaria sphenoid optic bones of Body T · (in middle) - Formed · by 10 foramen · form part or medial furcied houses pituitary gland · sella ↑ : - Floor Cranial orbit : base wall of each · · Flat bones -greater wing (basicranium) Lacrimal fosse houses foramen rotundum & ovale for trigeminal ( · - · Dome-like Clacrimal sac in life nerve collect tears & drain roof into nasal carity - foramen spinosum for meningeal artery coronal , sagittal, lambdoid squamous , forms upper jaw - · I - alveolar sockets hold teeth bony point betweet teeth (alveolarocesses 1 quamousart · forms inferomedial wall of orbit mpanic ( port ~ zygomatic hard ~ external process · forms antenor 2/2's of palate (roof of mouth) auditoryatus astoid (earanal) ethmoid Bones - sphenoid part I containing ↓ mastoid process Pronfel sinuses 2. Billed with air sinuses - the · Lateral wall s part of. forms angle of cheekbones of wall lateral orbital floor cranial activity and of part openings temporal bone procesa in · · near rest 8 on base facet of of skull dense of C Catlas) at occipital condites zygomable arch So temporal · Cygomatic process O Carotid Canal foramen holds spinal cord for carotid magnum artery · passageway · supplying the brain Fontanels Space between unfused bones Only movable ② Jugular foramen shifting of bones join : > - allow · membrane) birth and lower feath between (filled with fibrous during growing · holds · irregular opening · largest of brain temporal & occipital bones · diamond shape passageway for drainage bounded fused 6 · by halves at age yo of of frontal & parietal blood from brain to internal bones jugular vein · become 'bregma' fused at age of 18 months age · small · triangular shape Rused at 6-8 months of age · bounded by occipital & panefal bones · becomes 'lambda  Cranial vault elongated basin The Skull Neurocranium Neurocranium Base of skull Base of skull Cranial Fossa Neurocranium Frontal Bone Formed by 10 bones Forms forehead and 22 bones joined together by sutures - 4 single bones (Bordered outures) b part of the roof of the Cranial bones surround cranial cavity contain frontal - 3 paired bones · Parietal cranium gin us Bone frontal forehead : Forms of roof and part and partofem th thin cranial Flat bones bone layers · tissue - – 8 bones in contact with meninges its lateral wall forms roof of orbit Forms roof of the that project · temporal line of Bony case of the brain and · temporalis muscle frontal, parietal, brain and spinal sphenoid Nasal orbit its membranous coverings Cord Bone Bone – calvaria (skullcap) forms roof and walls relate to the canal Temporal Contains frontal (meninges) throat/neck Bone Facial bones support teeth and form 3 basins that comprise the cranial floor or base zygomatic sinus Dome-like roof Bone space/cavity – anterior fossa holds the frontal lobe of the brain carity nasal cavity and orbit Roof: calvaria of bone maxilla – middle fossa holds the temporal lobes of the brain – 14 bones with no direct contact with brain -skullcap – posterior fossa contains the cerebellum or meninges Floor: cranial base Swelling of the brain may force tissue through foramen mandible – attachment of facial and jaw muscles -basicranium magnum resulting in death  Parietal Bone occipitalcondyle eatens a of a (AHas) Skull in Infancy and Childhood Parietal Bone Temporal Bone Openings in Temporal Bone Occipital Bone allow bone to Neurocranium · becomes 'bregmal Neurocranium Fontanes bled shipf dus · largest main artery which > - space in between - · bounded by half Bordered by 4 - birth out diamond shape Cranial roof and part · carry blood to head Ribrous membrane unfused bones parietal Lateral wall and part of Rear and base of skull with ANTERIOR FONTANELLE fused 18 frontal & POSTERIOR FONTANELLE I Carotid] canal Spaces between unfused brain · at bone - and neck ap of its lateral walls sutures floor of cranial cavity Foramen magnum holds months of age - – coronal, – passage for internal spinal cord bones called fontanels Temporal lines of – squamous part carotid artery largest Small sagittal, – filled with fibrous temporalis muscle lambdoid and zygomatic process mandibular fossa and canal supplying the brain Skull rests on atlas at membrane diamond shape triangular shape Jugular foramen occipital condyles squamous TMJ arotid forman Hypoglossal canal transmits – allow shifting of bones bounded by halves of bounded by parietal & – tympanic part C – irregular opening during birth and growth of frontal & parietal bones occipital bones external auditory meatus jugular between temporal and hypoglossal nerve (CN XII) brain fused at 18 months of age Small fused at 6-8 months of age supplying tongue muscles · space between (ear canal) Pused occipital bones Triangle shape at 6-8 months age · · skull 2 frontal bones fuse by meatus Lateral auditory styloid process External occipital becomes ‘Bregma’ · Bounded · become becomes ‘Lambda’ styloid process – passageway for by parietal "lambda' sid mast – mastoid part drainage of blood protuberance for nuchal age six and occipital process mastoid process filled from brain to internal ligament bone Temporal lines with air sinuses – mastoiditis from ear jugular vein Nuchal lines mark neck infection muscles  Viscerocranium Sphenoid Bone Sphenoid Bone Sphenoid Bone Ethmoid Bone Ethmoid Bone Maxillary Bones Maxillary Bones Formed by 15 irregular Behind the incisors (front teeth) is bone Ethmoid Body of the sphenoid a pair of incisive foramina bone -6 paired bones – sella turcica Forms upper jaw Between the orbital cavities Palatine processes meet at the -3 singular – alveolar processes are bony points – houses pituitary gland Lateral walls and roof nasal intermaxillary suture at about 12 bones between teeth Lesser wing cavity weeks of fetal development Lesser wing – optic foramen – alveolar sockets hold teeth Failure to join causes cleft palate Cribriform plate and crista - ethmoid Greater wing galli Bone Forms inferomedial wall of orbit Greater wing – infraorbital foramen Body of sphenoid – foramen rotundum and Ethmoid air cells form ovale for trigeminal ethmoid sinus Superior and middle Forms anterior 2/3’s Medial and lateral nerve Perpendicular plate forms concha of hard palate pterygoid processes Sphenoid – foramen spinosum for part of nasal septum Perpendicular plate of meningeal artery sinus Concha (turbinates) on nasal septum lateral wall  Locations of Paranasal Palatine Bones Zygomatic Bones Lacrimal Bones Nasal Bones Inferior Nasal Conchae Vomer Mandible Sinuses Only movable bone L-shaped bone Forms bridge of – jaw joint between mandibular fossa Posterior 1/3 of the nose and supports and condyloid process Forms angles of the hard palate cheekbones and part cartilages of nose Form part of medial Holds the lower teeth Part of lateral nasal of lateral orbital wall wall of each orbit Often fractured by A separate bone Attachment of muscles of mastication wall Zygomatic arch is blow to the nose Lacrimal fossa – temporalis muscle onto coronoid process formed from temporal Not part of ethmoid Inferior half of the Part of the orbital houses lacrimal sac – masseter muscle onto angle of mandible process of zygomatic like the superior and nasal septum floor in life Mandibular foramen bone and zygomatic middle concha or Supports cartilage process of temporal – tears collect in Maxillary sinus fills maxillae bone turbinates of nasal septum Mental foramen bone lacrimal sac and drain Other bones containing sinuses are frontal, into nasal cavity ethmoid and sphenoid. Ramus, Angle and Body of The Vertebral Column AXIAL SKELETON AXIAL SKELETON Bones Associated With Skull Major Skull Cavities Newborn Spinal Curvature Mandible Primary curvature (1°) Secondary curvature (2°) Auditory ossicles 33 vertebrae and Develop in fetal period Spine exhibits one Develop in infancy & childhood – malleus, incus, and intervertebral discs of continuous C- fibrocartilage Curve of the thoracic and sacral Curve of the cervical and lumbar stapes shaped curve Five vertebral groups Known as primary -Concave posteriorly Hyoid bone THE VERTEBRAL COLUMN – 7 cervical in the neck -concave anteriorly curvature -inverse S-shaped -C- shaped – suspended from – 12 thoracic in the chest styloid process of – 5 lumbar in lower back skull by muscle and – 5 fused sacral ligament – 4 fused coccygeal – greater and lesser Variations in number of lumbar and sacral horn vertebrae  Abnormal Spinal Curvatures Intervertebral Foramen and Vertebral C1 (atlas) Adult Spinal Curvatures General Structure of Vertebra Intervertebral Discs Typical Vertebra Cervical Vertebrae Discs From disease, Intervertebral discs Body: short No body S-shaped vertebral posture, paralysis or – bind vertebrae together Body Intervertebral foramen Vertebral foramen: large & No spinous column with 4 congenital defect – absorb shock triangular process curvatures Scoliosis from lack Vertebral foramen – Notches between – spinal flexibility Foramen transversarium Ring-shaped adjacent vertebrae Secondary curvatures of proper form vertebral canal – gelatinous nucleus pulposus surrounded by anulus for bone – passageway for nerves develop after birth fibrosus (ring of fibrocartilage) -vertebral artery & veins to development of one Neural arch Has a facet for – herniated disc pressures spinal nerve or cord pass (C1-6) dense that will – lifting head as it begins vertebrae – 2 lamina to crawl develops Spinous process: short & articulate with Kyphosis is from – 2 pedicles bifid dense of C2 cervical curvature osteoporosis Typical cervical vertebrae vertebra – walking upright Processes develops lumbar Lordosis is from is C3, C4, C5 and C6 curvature weak abdominal – spinous, transverse Atypical cervical muscles and articular vertebrae: C1,C2 & C7  Vertebra C7 Typical Thoracic Vertebrae -wh to morm o Vertebral C2 (Axis) The Unique Atlas and Axis Atlas and Axis Articulation Lumbar Vertebrae Sacrum (Anterior View) Sacrum (Posterior View) a Long, non-bifid spinous process Strongest cervical vertebra Atlas (C1) supports the skull – concave superior articular facet Large transverse process Small 5 sacral vertebrae Has a dense Foramen Transmit 1 nod your head in “yes” movement Small foramen transversarium transversarium only ve