EXAM 2 KIN 2500 PART 1 Chapter 6 BONE TISSUE Functions of bone and the skeletal system Support Protection Assistance in movement Mineral storage and release Blood cell production Triglyceride storage Types of bones Long bones Bones that are longer than they are wide Provide strength structure and mobility Short bones Bones that are as wide as they are long Primary function is to provide support and stability with little to no movement Flat bones Bones whose principle function is either extensive protection or the provision of broad surfaces for muscular attachment These bones are expanded into broad flat plates Irregular bones Bones which from their peculiar form cannot be grouped as long short flat or sesamoid bone Serve various purposes in the body such as protection of nervous tissue affording multiple anchor points for skeletal muscle attachment and maintain pharynx and trachea support Sesamoid bones Bone embedded within a tendon or a muscle Anatomy of a bone Diaphysis shaft of the bone elongated Epiphyses the ends of long bones attachment points for ligaments and tendons Metaphysis contains the epiphyseal plate growth plate Articular cartilage Refers to hyaline cartilage on the articular surfaces of bones Often found in close contact with menisci and articular disks Not considered a part of either of these structures which are made entirely of fibrocartilage Periosteum Slippery covering over the bone tough membrane but NOT cartilage Fibrous layer dense irregular connective tissue Osteogenic layer development of osteons Medullary cavity Hollowed out part of the bone Endosteum Lining of narrow cavity Bone surface markings Depressions and openings Fissure narrow slit usually Foramen an opening between adjacent bones Processes that form joints Fossa shallow depression hips shoulders Sulcus groove or furrow Meatus tube like passageway or canal Condyle large round Fact thoracic vertebrae where the ribs join the sternum Head a large rounded projection on the end of a long bone Processes that form attachment points for connective tissues Crest a prominent edge ridge Epicondyle above a condyle Line a long narrow border Spinous process slender projection Trochanter very large projection Tubercle small eminence usually on a bone for attachment Tuberosity large rounded roughened projection of a bone of a tendon Histology of bone Osteogenic cells the only bone cells that divide differentiate Osteoblasts synthesize and secrete a collagen matrix and and develop into osteoblasts calcium salts when the area surrounding an osteoblast calcifies the osteoblast becomes trapped and transforms into an osteocyte Osteocytes the most common and mature type of bone cell The cells that break down and reabsorb bone stem from monocytes and macrophages Osteoclasts Resorbs bone tissue Critical in the maintenance and repair and remodeling of bones of the vertebral skeleton Histology of compact bone Osteons The main part of compact bone has vertically oriented blood vessels Central canal Circular channel running longitudinally in the center of an osteon of mature compact bone containing blood and lymphatic vessels and nerves extracellular matrix of increasing diameter surrounding a small network of blood vessels lymphatics and nerves located in the center canal Concentric lamellae Circular plates of mineralized Lacunae Holds the osteocyte Canaliculi Fluid filled bridges that connect the cells Interstitial lamellae The lamella that is between the osteons Circumferential lamellae Older osteons that have been pushed to the outside of the bone lays right inside the periosteum Bone scan Blood and nerve supply of bone Periosteal arteries Enters the diaphsis and carries the blood to periosteum and the outer layers of the bone the Nutrient arteries Enters the diaphysis at an oblique angle Nutrient foramen The nutrient vein and the nutrient Metaphyseal artery Enters the metaphyses of a long bone and carries the blood to the proximal and distal ends of the bone and the medullary cavity arteries travel through this opening in the periosteum and supplies the red bone marrow and bone tissue of the metaphyses supplies the red bone marrow and bone tissue of the metaphyses Epiphyseal artery Enters the epiphyses of a long bone and Remodeling of bone by new bone tissue Bone remodeling The ongoing replacing of old bone tissue o Bone resorption The removal of minerals and collagen o Bone deposition Lays down collagen fibers and fibers from the bone by osteoclasts minerals by the osteoblasts Clinical connection Paget s disease Chronic condition of bone and is characterized by the disorder of normal bone remodeling it is VERY RARE and is mostly found in CHILDREN Common types of bone fractures Comminuted fracture Bone is splintered crushed or broken into pieces at the site of impact Greenstick fracture Partial fracture in which one side of the bone is broken and the other side bends occurs only in children Impacted fracture One end of the bone has been forcefully driven into the interior of the other Pott s fracture ALWAYS occurs at the distal end of a lateral leg bone fibula causes serious injury to the distal articulation radius causes injury to the distal articulartion the tibia Colle s fracture Distal end of the later bone of the forearm Stress fracture MOST COMMON FRACTURE 25 occur in