Popular in Anatomy and Physiology I
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This 7 page Bundle was uploaded by kgrunwaldt on Monday January 25, 2016. The Bundle belongs to BIOL 214 at Truman State University taught by Dr. Guffey in Spring 2016. Since its upload, it has received 20 views. For similar materials see Anatomy and Physiology I in Science at Truman State University.
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Date Created: 01/25/16
Bones Skeletal Cartilag Skeletal cartilage made of cartilage tissue consists primarily of water 0 Perichondrium dense irregular connective tissue that surrounds cartilage Hyaline glassy provides support with flexibility and resilience Elastic contain stretchy elastic fibers to withstand bending Fibrocartilage highly compressible and have tensile strength Appositional growth growth from outside Interstitial growth growth from inside Classification of Bones Axial skeleton forms the long axis of the body and includes the bones of the skull vertebral column and rib cage Appendicular skeleton consists of the bones and the upper and lower limbs and the shoulder boneship bones Long bones considerably longer than they are wide 0 Contains shaft and two ends 0 All bones are long bones except for patella wrist and ankle bones Short bones roughly cube shaped bones of wrist and ankle o Sesamoid bones shaped like sesame seeds a special type of short bone that form in a tendon examplepatella Flat bones thin flattened and curved sternum scapula ribs and skull bones Irregular bones complicated shapes vertebrae and hip bones Functions of Bones Suppon Protection Movement Mineralgrowth factor storage Blood cell formation Triglyceride fat storage Bone Structure Osteogenic Cell stem cell Osteoblast matrixsynthesizing cell responsible for bone growth Osteocyte mature bone cell that maintains bone matrix Osteoclast boneresorbing cell Bone Markings Projections include heads trochanters spines Depressions include fossae sinuses foramina and grooves Bone Textures Compact bone external layer Spongy bone internal layer also called cancellous bone Trabeculae honeycomb of small needlelike or flat pieces Structure of a Long Bone o Diaphysis shaft that forms the long axis of the bone 0 Medullary cavity thick collar of compact bone 0 Yellow Marrow cavity medullary cavity containing fat o Epiphyses bone ends 0 Epiphyseal plate a disc of hyaline cartilage that grows during childhood to lengthen a bone 0 Periosteum external surface of the entire bone except the joint white doublelayered membrane 0 Nutrient Foramina where nerves lymph vessels and blood vessels enter the diaphysis o Endosteum covering of internal bone surfaces Diploe spongy bone in flat bones that resembles a sandwich Red marrow hematopoietic tissue full of blood vessels Microsconic Anatomv of Bones Compact Bone O OsteonHaversian System structural unit of compact bone weight bearing pillars o Lamella matrix tube located in the bone matrix resembles growth rings of a tree trunk 0 Central CanalHaversian Canal runs through the core of the osteon contains small blood vessels and nerve fibers 0 Perforating canals secondary canals connect the blood and nerve supply of the periosteum to those in the central canals and the medullary cava 0 Canaliculi connect the lacunae to each other and to the central canal o Interstitial lamellae lie between intact osteons fill the gaps between forming osteons or are remnants of osteons that have been cut through bone remodeling O Circumferential lamellae located deep to the periosteum and superficial to the endosteum extend around the entire circumference of the diaphysis and resist twisting of the long bone Spongy Bone o Trabeculae align precisely along lines of stress and help bone resist stress 0 No osteons present 0 Nutrients reach spongy bone through diffusion Chemical Composition of Bone Organic components osteogenic cells osteoblasts osteocytes osteoclasts and osteoid make up the organic matrix 0 Osteoid contains ground substance and collagen fibers 0 Organic structures contribute to flexibility structure and tensile strength 0 Sacrificial bonds between collagen molecules break on impact and dissipate energy to prevent force from turning into a fracture 65 of the mass consists of inorganic hydroxyapatitesmineral salts and give bone its hardness Bone Develoloment OssificationOsteogenesis the process of bone formation Formation of the Bony Skeleton 0 Human embryo is made of hyaline cartilage 0 When bone develops from fibrous membrane it is called intramembranous ossification and the bone is called membrane bone 0 Bone development from hyaline cartilage is called endochondral ossification resulting in endochondral bone lntramembranous Ossification 0 Results in the formation of cranial bones of the skull frontal parietal occipital and temporal and clavicles I Ossification centers appear in the fibrous connective tissue membrane I Bone matrix osteoid is secreted within the fibrous membrane and calcifies I Woven bone and periosteum form I Lamellar bone replaces woven bone just deep to the periosteum Red marrow appears Endochondral Ossification o All other bones are formed by this 0 Formation begins in the center of the hyaline cartilage shaft called the primary ossification center and mesenchymal cells turn into osteobasts I A bone collar is laid down around the diaphysis of the hyaline cartilage model I Cartilage in the center of the diaphysis calcifies and then develops cavities I The periosteal bud invades the internal cavities and spongy bone begins to form I The diaphysis elongates and a medullary cavity forms as ossification continues Secondary ossification centers appear in the epiphyses I The epiphyses ossify When completed hyaline cartilage remains only in the epiphyseal plates and articular cartilages Bone Remodeling Bone deposit and bone resorption occur both at the surface of the periosteum and the endosteum and constitute bone remodeling o Coordinated by osteobasts and osteoclasts called remodeling units 0 Bone deposits occur wherever bone is injured or added bone strength is required 0 Bone resorption accomplished by osteoclasts bone removal Hormone controls involve parathyroid hormone PTH produced by the parathyroid glands O Calcitonin produced by parafollicular cells of the thyroid is involved as well 0 High PTH levels stimulate osteoclasts to resorb bone and release calcium to the blood Bone Repair Fractures breaks in the bone 0 Classified by I Position in the bone ends nondisplaced fractures bone ends retain their position displaced fractures do not I Completeness of the break if not broken through it is a complete fracture if not it is an incomplete fracture I Orientation of the break if break parallels the long axis it s linear if not it s transverse I Whether the fracture penetrates the skin open fracture penetrates closed fracture does not 0 Repair in a simple fracture involves four major stages I A hematoma forms blood vessels are torn and hemorrhage resulting in a mass of clotted blood at the fracture site I Fibrocartilaginous callus forms granulation tissuesoft callus forms phagocytes clean up debris fibroblasts and osteoblasts begin to reconstruct the bone fibrocartilaginous callus is formed to splint the broken bone I Bony callus forms new bone trabeculae begin to appear and convert the fibrocartilaginous callus into a bony callus I Bone remodeling occurs bony callus is remodeled for several months excess material on the diaphysis exterior is removed compact bone reconstructs shaft walls Homeostatic lmbalances of Bone Osteomalacia includes a number of disorders in which the bones are inadequately mineralized bones weaken pain with weight on affected bones caused by insufficient calcium Rickets an analogous disease in children bowed legs deformities of the pelvis skull and rib cage are common caused by insufficient calcium Osteoporosis refers to a group of diseases in which bone resorption outpaces bone deposit Paget s Disease characterized by excessive and haphazard bone deposit and resorption usually localized spine pelvis femur and skull are most often deformed and painful
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