Review Questions for Bones and the Skeletal System Note this is NOT an all inclusive list of items that will be presented on the test 1 Describe in detail Intramembranous Ossification of Bone a Forms the cranial bones of the skull and clavicles b Proliferation zone cells at the top divide quickly pushing the epiphysis away from the diaphysis and lengthening the entire long bone c Hypertrophic zone chondrocytes lacunae erode and enlarge leaving interconnecting spaces d Calcification zone the surrounding cartilage matrix calcifies the chondrocytes see matrix begins to deteriorate allowing blood vessels to invade e Ossification zone osteoclasts partly erode the cartilage spicules then osteoblasts cover them with new bone 2 Describe in detail Endochondral Ossification of Bone a Bone collar forms around diaphysis of hyaline cartilage model chondrocytes enlarge b 2 cartilage calcifies in the center of the diaphysis and then develops cavities c 3 the periosteal bud invades the internal cavities and spongy bone forms d The diaphysis elongates and a medullary cavity forms e The epiphysis ossify 3 List and describe the different types of bone cells a Osteoblasts bone forming cells that secrete the bone matrix b Bone lining cells flat cells believed to help maintain matrix c Osteoclasts derived from hematopoietic stem cells that become macrophages Multinucleated Reabsorb bone d Osteoblast bone forming cell e Osteocyte mature monitor and maintain bone matrix f Osteogenic osteoprogenitor cells stem cells of periosteum and endosteum that differentiate into osteoblasts or bone lining cells g Osteoid unmineralized bone h Osteon structural unit of compact bone 4 What is the functional significance of cartilage What is it used for in the skeletal system How many different types of cartilage exist in the human body What happens when cartilage wears down or becomes torn a Model in fetal skeleton Serves as cushion at joints b Hyaline cartilage Articular cartilage at ends of long bones nose trachea larynx c Fibrocartilage Intervertebral discs menisci of knee contains thick collagen fibers that resist tensile stretching and compressional forces d Elastic cartilage structures such as ears contains elastic fibers e Damage is painful and can cause joint issues 5 Describe the two methods by which cartilage grows a Appositional Growth Cartilage forming cells in the surrounding perichondrium secrete new matrix against external face of existing cartilage tissue b Interstitial Growth the lacunae bound chondrocytes divide and secrete new matrix expanding cartilage from within 6 Do bones need a blood supply Why or Why not a Bone is living tissue and needs nutrients via blood supply The Central Haversian canal is central to the entire structural and functional unit that contains blood vessels and nerves that supply the bone 7 Describe the parts of a long bone a Epiphysis bone ends b Diaphysis shaft forms the long axis of the bone c Medullary Cavity contains yellow marrow and the compact bone d Epiphyseal line between the diaphysis and epiphysis of an adult long bone e Epiphyseal plate growth plate is a disc of hyaline cartilage that grows during childhood to lengthen the bone f Periosteum double layered membrane covers the external surface of the entire bone expect joint surfaces 8 What is the anatomical structure found to be associated with short flat or irregular shapes a All consist of thin plates of spongy bone covered by compact bone 9 List and describe all of the different types of fractures that could occur to bone a Complete if it breaks all the way through b Incomplete does not break all the way through c Compound open breaks the skin d Simple closed does not break skin 10 Does bone need to be stimulated to be healthy Why a Yes stress signals bone to strengthen and rebuild Prevents atrophy 11 What is the process of bone fracture repair a Hematoma forms bone cells deprived of nutrition die and the tissue at the site becomes swollen and painful b fibrocartilaginous soft callus forms fibroblasts produce collagen fibers that span the span the break and connects the broken bone ends splints broken bone c Bony hard callus forms osteoblasts begin forming spongy bone osteoblasts begin to lay down trabeculae of new bone around and within fibrocartilaginous callus Gradually fibrocartilaginous callus is replaced by immature bone d Bone Remodel occurs compact bone is laid down to reconstruct the shaft walls 12 Compare and contrast appositional growth and interstitial growth in bone a Interstitial growth chondrocytes divide isogenous groups a cluster of chondrocytes all formed through division of a single progenitor cell daughter cells produce matrix which pushes cells apart i e growth from within b Appositional growth chondroblasts divide in inner layer of the perichondrium produce matrix differentiate into chondrocytes i e growth by adding to the outer surface 13 What is Wolff s Law a Bones grow or remodel in response to demands placed on them 14 Lucy Mae has been bedridden for 15 years and she has had numerous fractures in her pelvis and legs Why What could be done to prevent any further fractures a Bone cells are experience atrophy because of the use it or lose it effect Movement will help strengthen bones 15 What is the interosseous membrane What would happen if this deteriorated a is a thick dense fibrous sheet of connective tissue that spans the space between two bones 16 What is the difference s between the axial and appendicular skeleton a Axial Skull thoracic cage vertebral column b Appendicular Pectoral girdle limbs pelvic girdle 17 Calcium and Vitamin D are important to maintain good bone health Why a Calcium and vitamin D work together to protect your bones calcium helps build and maintain bones while vitamin D helps your body effectively absorb calcium 18 If a child does not receive enough vitamin D in his her diet what medical condition might result Why a Rickets because not enough calcium is stored in the bones 19 What contributes to bone remodeling Be sure you include information about the particular bone cells that may be crucial for bone remodeling a Bone resorption osteoclasts move along a bone surface digging depressions grooves as they break down the bone matrix osteoclasts break down the tissue in bones and release the minerals resulting in a transfer of calcium from bone tissue to the blood b Bone deposition the formation of new bone by addition of minerals and collagen fibers by osteoblasts