6Axial Skeleton Function Support and protect organs in dorsal and ventral body cavitiesProvide surface area for muscle attachment:Adjust position of head, neck, & trunkPerform respiratory movementsStabilize appendicular skeleton
7Bones of the Axial Skeleton The skull: 22 bones8 cranial bones:form the braincase or cranium14 facial bones:protect and support entrances to digestive and respiratory tractsSkull bones interconnect at immovable joints called suturesDense fibrous CT
9Cranial Bones Enclose the cranial cavity Which contains the brain: and its fluids, blood vessels, nerves, and membranes
10The Facial Bones Superficial facial bones: Deep facial bones: for muscle attachmentMaxillary, Lacrimal, Nasal, Zygomatic, and MandibleDeep facial bones:separate the oral and nasal cavitiesform the nasal septumPalatine bones, Inferior nasal conchae, and Vomer
11The Maxillary BonesThe largest facial bonesFigure 7–10a
12Functions of the Maxillary Bones Support upper teethForm inferior orbital rimForm lateral margins of external naresForm upper jaw and hard palateContain maxillary sinuses (largest sinuses)
17Functions of the Nasal Bones Support the bridge of the noseConnect to cartilages of the distal part of the nose (external nares)VomerForms the inferior portion of the bony nasal septumInferior Nasal ConchaeTo create air turbulence in the nasal cavityTo increase the epithelial surface areaTo warm and humidify inhaled air
19The Hyoid Bone Function: Supports the larynx Attaches muscles of the larynx, pharynx, and tongueFigure 7–12c
20Marks of the Hyoid Bone Greater horns (greater cornua): support larynxattach muscles of the tongueLesser horns (lesser cornua):attach stylohyoid ligamentssupport hyoid and larynx
21Skull Four major sutures: Lambdoid: Corona: Sagittal: Squamous: - separates occipital bone from parietal bonesCorona:- separates frontal bone from parietal bonesSagittal:- separates parietal bonesSquamous:- (2) separates temporal bone from parietal bone
22SuturesThe immovable joints of the skullFigure 7–3a, b
25The Orbital ComplexPortions of 7 cranial and facial bonesFigure 7–13
26The Orbital Complex Forms the eye sockets (orbits): frontal bone (roof)maxillary bone (floor)maxillary, lacrimal and ethmoid bones (orbital rim and medial wall)sphenoid and palatine bones
27The Nasal Complex Bones of the nasal cavities and paranasal sinuses Figure 7–14
28The Nasal Complex: Sinuses air filled chambers inside flat bonesFunction:Reduce weight of boneHouse mucus membranes that moisten and clean incoming airFound in:Sphenoid, ethmoid, frontal, palatine, and maxillary bones
29The differences between the skulls of infants, children, and adults.
30Skull DevelopmentIntramembranous ossification from many centers of ossificationDuring development:brain grows more rapidly than cranial bonesGrowing skull bones are held together by bands of fibrous CT to provide flexibilityExpansion of brain, compression for birthLarge intersections of CT between the bones = fontalels (“soft spots”)Persist until age 5Around age 5:Brain stops growing in size, solid sutures form between cranial bones
31The Infant Skull Fusion is not complete at birth: Fontanels 2 frontal bones4 occipital bonesseveral sphenoid and temporal elementsFontanelsAre areas of fibrous connective tissue (soft spots)Cover unfused sutures in the infant skullAllow the skull to flex during birth
32The 4 Fontanels Anterior fontanel: Occipital fontanel: frontal, sagittal, and coronal suturesOccipital fontanel:lambdoid and sagittal suturesSphenoidal fontanels:squamous and coronal suturesMastoid fontanel:squamous and lambdoid sutures
36In which bone is the foramen magnum located? sphenoidoccipital boneethmoidparietal bone
37Tomás suffers a blow to the skull that fractures the right superior lateral surface of his cranium. Which bone is fractured?frontal boneright temporal boneright parietal boneethmoid
38Which bone contains the depression called the sella turcica Which bone contains the depression called the sella turcica? What is located in this depression?sphenoid bone; pituitary glandethmoid; olfactory epitheliumtemporal bone; inner earlacrimal bone; tear apparatus
39The vertebral regions, the curvatures of the vertebral column, and their functions.
40The Vertebral Column: 26 Bones The spine or vertebral column:protects the spinal cordsupports the head and body7 cervical vertebrae (C1-C7)12 Thoracic vertebrae (T1-T12)5 Lumbar vertebrae (L1-L5)1 Sacrum (5 fused)1 Coccyx (3-5 fused)
41Regions and Curves of the Vertebral Column 26 bones:24 vertebrae, the sacrum, and coccyxVertebral column is not straight4 curves bring the weight of the body in line with the central axisFigure 7–16
44Characteristics of the Sacrum and Coccyx is curved, more in males than in femalesprotects reproductive, urinary, and digestive organsThe coccyx:attaches ligaments and a constricting muscle of the anus
454 Curvatures of the Vertebral Column Cervical curveThoracic curveLumbar curveSacral curve
46Primary Curves Thoracic and sacral curves: are called primary curves (present during fetal development)or accommodation curves (accommodate internal organs)
47Secondary Curves Lumbar and cervical curves: are called secondary curves (appear after birth in first year of life)or compensation curves (shift body weight for upright posture)Necessary for bipedalismCervical: holds head upLumbar: standing
49Construction of Column Vertebral body: stackingtransfers weight along the spineIntervertebral disc:Spacing between bodies (not C1 and C2)Annulus Fibrosus: OutsideFibrocartilageNucleus pulposus: InsideGel (cushion)Absorbs ShockLoss of water from discs = shrinking height
50Construction of Column Elastic ligaments:link bodies for alignmentIntervertebral foramen:holes formed by spacing from discs, allow spinal nerves to exit columnVertebral arch:Bone attached to vertebral body, with body it forms vertebral foramenVertebral Foramen:Hole for spinal cordVertebral Canal:Bony canal for spinal cordFormed by stacking of vertebral foramen
53Spina bifidaVertebral arch fails to develop correctly at 3 weeks (fetus) and the spinal cord is unprotected or even exposed4/1000 births show some degreeDue to lack of folic acid
54Why does the vertebral column of an adult have fewer vertebrae than that of a newborn? Vertebrae are absorbed as adult stature is reached.Newborns require more support in the cervical region.The sacrum and coccyx fuse post-puberty.Vertebrae are formed that later become ribs.
55What is the importance of the secondary curves of the spine? balances weight of headbalances weight on lower limbsallows walkingprovides greater flexibility
56superior articular processes pedicles transverse processes When you run your finger along a person’s spine, what part of the vertebrae are you feeling just beneath the skin?superior articular processespediclestransverse processesspinous processes
57Joe suffered a hairline fracture at the base of the dens Joe suffered a hairline fracture at the base of the dens. Which bone is fractured, and where is it located?second cervical vertebra; posterior neckfirst cervical vertebra; posterior neckoccipital bone; posterior base of skullsacrum; posterior pelvis
58thoracic lumbar sacral cervical Examining a human vertebra, you notice that, in addition to the large foramen for the spinal cord, two smaller foramina are on either side of the bone in the region of the transverse processes. From which region of the vertebral column is this vertebra?thoraciclumbarsacralcervical
59Why are the bodies of the lumbar vertebrae so large? They develop first and therefore have longer to grow.To provide more flexibility.To distribute weight over a larger area.To provide greater protection to the lumbar spinal nerves.
60The significance of articulations between ribs, thoracic vertebrae, and sternum.
61The Thoracic Cage The skeleton of the chest: Consists of: supports the thoracic cavityConsists of:24 Ribs1 sternum (breastbone)
62The Sternum The sternum: a flat bone in the midline of the thoracic wall
63The Rib CageFormed of ribs and sternumFigure 7–22a
64Articulations of Ribs and Vertebrae Figure 7–22b
65Functions of the Thoracic Cage Protects organs of the thoracic cavity:heart, lungs, and thymusAttaches muscles:for respirationof the vertebral columnof the pectoral girdleof the upper limbs
67Functions of Ribs Ribs: Rib movements (breathing): are flexible are mobilecan absorb shockRib movements (breathing):affect width and depth of thoracic cagechanging its volume
68Ribs Ribs (costae): Ribs are divided into 3 types: are 12 pairs of long, curved, flat bonesextending from the thoracic vertebraeRibs are divided into 3 types:1. 7 pairs of true ribs:Separate cartilage to attach to sternum2. 3 pairs of false ribs:Common shared cartilage to attach to sternum3. 2 pairs of floating ribs:- no cartilage, no attachment to sternum
69KEY CONCEPT The axial skeleton: Vertebrae: protects the brain, spinal cord, and visceral organs of the chestVertebrae:conduct body weight to the lower limbsLower vertebrae are larger and stronger:because they bear more weight
70How could you distinguish between true ribs and false ribs? True ribs attach directly to the sternum by their own costal cartilage.True ribs are entirely bony.False ribs are not part of the thoracic cage.True ribs are attached only to the sternum.
71Improper administration of cardiopulmonary resuscitation (CPR) can result in a fracture of which bone(s)?cervical vertebra and ribsthoracic vertebra and ribssternum and thoracic vertebrasternum and ribs
72What are the main differences between vertebrosternal and vertebrochondral ribs? Vertebrosternal ribs attach to the sternum.Vertebrochondral ribs attach to costal cartilage.Vertebrosternal ribs increase in curvature and length fromAll of the above are true.