Review Questions for Bones and the Skeletal SystemNote: this is NOT an all-inclusive list of items that will be presented on the test.1. Describe in detail Intramembranous Ossification of Bonea. Forms the cranial bones of the skull and claviclesb. Proliferation zone-cells at the top divide quickly, pushing the epiphysis away from the diaphysis and lengthening the entire long bonec. Hypertrophic zone-chondrocytes lacunae erode and enlarge, leaving interconnecting spacesd. Calcification zone-the surrounding cartilage matrix calcifies, the chondrocytes see, matrix begins to deteriorate allowing blood vessels to invadee. Ossification zone-osteoclasts partly erode the cartilage spicules then osteoblasts cover them with new bone;2. Describe in detail Endochondral Ossification of Bonea. Bone collar forms around diaphysis of hyaline cartilage model-chondrocytes enlargeb. 2) cartilage calcifies in the center of the diaphysis and then develops cavitiesc. 3) the periosteal bud invades the internal cavities and spongy bone formsd. The diaphysis elongates and a medullary cavity formse. The epiphysis ossify 3. List and describe the different types of bone cells.a. Osteoblasts-bone forming cells that secrete the bone matrixb. Bone lining cells - flat cells believed to help maintain matrixc. Osteoclasts - derived from hematopoietic stem cells that become macrophages. Multinucleated. Reabsorb bone.d. Osteoblast - bone forming celle. Osteocyte - mature, monitor and maintain bone matrixf. Osteogenic (osteoprogenitor) cells - stem cells of periosteum and endosteum that differentiate into osteoblasts or bone lining cellsg. Osteoid-unmineralized boneh. Osteon-structural unit of compact bone4. 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, larynxc. Fibrocartilage = Intervertebral discs, menisci of knee, contains thick collagen fibers that resist tensile (stretching) and compressional forcesd. Elastic cartilage = structures such as ears, contains elastic fiberse. 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 tissueb. 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 endsb. Diaphysis-shaft, forms the long axis of the bonec. Medullary Cavity-contains yellow marrow and the compact boned. Epiphyseal line-between the diaphysis and epiphysis of an adult long bonee. Epiphyseal plate-growth plate, is a disc of hyaline cartilage that grows during childhood to lengthen the bonef. Periosteum-double layered membrane covers the external surface of the entire bone expect joint surfaces8. 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 bone9. List and describe all of the different types of fractures that could occur to bone.a. Complete-if it breaks all the way throughb. Incomplete-does not break all the way throughc. Compound/open-breaks the skind. Simple/closed-does not break skin10.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 painfulb. fibrocartilaginous (soft) callus forms-fibroblasts produce collagen fibers that span the span the break and connects the broken bone ends-splints broken bonec. Bony (hard) callus forms-osteoblasts begin forming spongy bone, osteoblasts begin tolay down trabeculae of new bone around and within fibrocartilaginous callus. Gradually fibrocartilaginous callus is replaced by immature boned. Bone Remodel occurs-compact bone is laid down to reconstruct the shaft walls12. 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 withinb. -Appositional growth• chondroblasts divide in inner layer of the perichondrium• produce matrix• differentiate into chondrocytes i.e. growth by adding to the outer surface13. 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 bones16.What is the difference(s) between the axial and appendicular skeleton?a. Axial = Skull, thoracic cage, vertebral columnb. Appendicular = Pectoral girdle, limbs, pelvic girdle17. 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 calcium18. If a child does not receive enough vitamin D in his/her diet, what medical condition might result? Whya. 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 thetissue in bones and release the minerals, resulting in a transfer of