!1!Exam!2!review:!skeletal,!joints,!nervous!systems!!Function!of!bones!• Support!for!body!and!soft!organs!o Bones!of!legs,!pelvic!girdle,!vertebral,!and!vertebral!column!support!weight!of!erect!body!• Protection!for!brain,!vital!organs,!ribs!and!sternum!protect!lungs/heart,!vertebrae!protect!spinal!cord!• Movement!as!skeletal!muscles!use!the!bones!as!levers!to!move!body!• Storage!of!minerals!(calcium!and!phosphorous)!and!growth!factors,!99%!of!the!body’s!calcium!is!stored!in!bones,!85%!of!body’s!phosphorous!store!in!bone!• Adipose!tissue!is!found!in!yellow!marrow!of!certain!bones!• Blood!cell!formation!(hematopoiesis)!in!red!marrow!cavities,!all!blood!cells!are!made!in!the!marrow!of!certain!bones!!Skeletal!Cartilages!• Hyaline!o Provide!support,!flexibility,!resilience!o Most!abundant!• Elastic!o Similar!to!hyaline,!but!contain!elastic!fibers!• Fibrocartilage!o Collagen!fibers!have!great!tensile!streng th!• Contain!very!few!to!no!blood!vessels!or!nerves !• Dense!connective!tissue!girdle!of!perichondrium!contains!bloods!vessels!for!nutrient!delivery!to!cartilage!!Bones!of!the!Skeleton!• 206!named!bones!in!human!body!• 2!large!groups! !o axial! forms!long!axis!of!body.!Includes!the!bones!of!the!skull,!vertebral!column,!and!rib!cage! these!bones!are!involved!in!protection,!support,!and!carrying!other!body!parts!o appendicular!! bones!of!upper!and!lower!limbs!and!the!girdles!(shoulder!bones!and!hip!bones)!that!attach!them!to!the!axial!skeleton.!Involved!in!locomotion!and!manipulation!of!the!environment!!Skull!• 2!sets!of!bones!o cranial! enclose!brain!in!cranial!cavity! provide!sites!of!attachment!for!head!and!neck!muscles!!2!o facial! framework!for!face! cavities!for!special!sense!organs! openings!for!air/food! site!of!attachment!for!teeth!and!muscles!of!facial!expression!!Paranasal!Sinuses!• mucosaTlined,!airTfilled!spaces:!warm!and!moisten!air,!lighten!skull,!enhance!resonance!of!voice,!found!in!frontal,!sphenoid,!ethmoid,!and!maxillary!bones!!Vertebral!Column!!• functions!o transmits!weight!of!trunk!to!lower!limbs,!surrounds!and!protects!spinal!cord,!flexible!curved!structure!containing!26! irregu lar!bones! cervical!7,!thoracic!12,!lumbar!5!• curvatures!o increase!resilience!and!flexibility!of!spine! two!posteriorly!concave!curvatures!(cervical!and!lumbar)! two!posteriorly!convex!curvatures!(thoracic!and!sacral)!o abnormal!spine!curvatures! scoliosis!(abnormal!lateral!curve)! kyphosis!(hunchback)! lordosis!(swayback)!!Intervertebral!Discs!!• cushionTlike!pad!composed!of!two!parts!o nucleus!pulposus:!inner!gelatinous!nucleus!that!gives!disc!its!elasticity!and!compressibility!o annulus!fibrosus:!outer!collar!composed!of!collagen!and!fibrocartilage!!Comparison!of!Female!and!Male!Pelves!• female!o adapted!for!childbearing,!true!pelvis!(inferior!to!pelvic!brim)!defines!birth!canal,!cavity!of!the!true!pelvis!is!broad,!shallow,!and!has!greater!capacity!• male!o tilted!less!forward,!adapted!for!support!of!male’s!heavier!build!and!stronger!muscles,!cavity!of!true!pelvis!is!narrow!and!deep!!Compact!Bone!• dense!bone!that!contain!many!cylinder!shaped!units!called!osteon!• !collagenous!protein!fibers!and!mineral!deposits!of!calcium!phosphate!salts!are!found!here!• within!each!osteon!is!a!central!(Haversian)!canal!that!nerves!and!blood!vessels!use!for!passage!o surrounded!by!concentric!layers!of!calcified!bone!matrix!!3!o haversian!canals!allow!passage!of!blood!vessels,!lymphatic!vessels,!and!nerve!fibers!o each!of!the!concentric!matrix!“tubes”!that!surrounds!a!Haversian!canal!is!known!as!lamella!o all!the!collagen!fibers!in!a!particular!lamella!run!in!a!single!direction,!while!collagen!fibers!in!adjacent!lamellae!will!run!in!opposite!direction.!Allows!bones!to!better!withstand!twisting!forces!o perforating!Volkmann’s!canals!–!at!right!angles!to!central!canal,!connect!blood!vessels!and!nerves!of!periosteum!and!central!canal!o lacunae!are!small!cavities!that!contain!osteocytes!o canaliculi!are!hairTlike!canals!that!connect!lacunae!to!each!other!and!the!central!canal!• osteons!are!oriented!longitudinally!in!long!bones!along!lines!of!force!o lamellae!are!weightTbearing!columnTlike!matrix!tubes!o central!(Haversian)!canal!contains!blood!vessels!and!nerves!!Spongy!Bone!(trabeculae!or!cancellous!bone)!• red!bone!marrow!produces!red!blood!cells!• in!adults,!red!bone!formation!occurs!in!spongy!bone!of!skull,!ribs,!sternum,!vertebrae,!and!in!ends!of!long!bones!• osetocytes!are!located!in!trabeculae!and!gets!nutrients!via!diffusion!• trabeculae!align!along!lines!of!stress,!no!osteons,!contain!irregularly!arranged!lamellae,!osteocytes,!and!canciculi,!capillaries!in!endosteum!supply!nutrients!!Bones!by!Shape!• long!bones:!longer!than!they!are!wide!• short!bones:!cubeTshaped!bones!in!wrist!and!ankle.!Sesamoid!bones!(within!tendons!e.g.!patella)!• flat!bones:!thin,!flat,!slightly!curved!(scapulae,!sternum,!shoulder!blades,!ribs)!• irregular:!complicated!shapes!(vertebrae,!hip!bones,!sphenoid/ethmoid!bones)!• wormian!bones!are!small!bone!pieces!that!occur!within!a!suture!in!the!cranium—not!included!in!206!bones!!Structure!of!a!Long!Bone!• epiphysis!o thin!layer!of!compact!bone!covering!an!interior!of!spongy!bone!at!the!end!of!the!long!bone!o epiphyseal!line!(disc)!is!the!remnant!of!the!growth!plate!o articular!(hyaline)!cartilage!on!joint!surfaces!cushions!the!bone!ends!and!reduces!friction!during!movement!• diaphysis!o the!shaft!of!a!long!bone,!between!the!epiphyses!o compact!bone!collar!surrounds!medullary!(marrow)!o medullary!cavity!in!adults!contains!fat!(yellow!marrow)!!4!• metaphysis!o region!of!mature!bones!where!the!diaphysis!meets!the!epiphysis!o epiphyseal!plate!in!a!growing!bone,!the!epiphyseal!plate!is!formed!of!hyaline!cartilage!divided!into!4!zones!of!cells! under!the!influence!of!GH,!the!plate!continues!to!grow,!giving!length!to!the!bone! when!bone!growth!exceeds!cartilage!growth,!beginning!at!puberty,!the!epiphyseal!plate!is!slowly!lost! growth!of!long!bones!stops!when!the!cartilage!is!completely!gone!• medullary!cavity!o cavity!of!the!shaft,!contains!yellow!marrow!(mostly!fat)!in!adults!and!contains!red!marrow!(for!blood!cell!formation)!in!infants!!Membranes!of!Bone!• Periosteum!o Divided!into!an!outer!fibrous!layer!and!an ! inner!osteogenic!layer!
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