Anatomy and Physiology Chapter 6 Questions with Correct Solutions

Number of named bones in human body - 206 Axial Skeleton - Long axis of body Skull, vertebral column, rib cage Appendicular Skeleton - arms and legs Long Bones - bones that are longer than they are wide Short Bones - cube shaped bones, wrist/ankle, sesamoid bones Flat Bones - thin, flat, slightly curved; sternum Irregular Bones - complicated shapes; vertebrae, coxal Functions of Bones - support, protection, movement, and storage Hematopoiesis - blood cell formation in red marrow 3 Levels of Structure - gross anatomy, microscopic, chemical Bone Textures - compact and spongy bone Compact Bone - dense outer layer, smooth and solid Spongy Bone - Honeycomb of flat pieces of bone deep to compact called trabeculae Diaphysis - Tubular shaft forms long axis Compact bone surrounding medullary cavity Epiphysis - bone ends, external compact bone, internal spongy bone, articular cartilage covers articular surfaces Bone Markings - projections, depressions, openings, most indicate stresses created by muscle pull or joint modifications Growth Arrest Lines - horizontal lines on bones, proof of illness, when bones stop growing so nutrients can help fight diease Interstitial growth - increase in length of long bones, requires presence of epiphyseal cartilage Appositional growth - increase in bone thickness Epiphyseal Plate Closure - bone lengthening ceases, bone of epiphysis and diaphysis fuses Growth Hormone - most important in stimulating epiphyseal plate activity in infancy and childhood Thyroid Hormone - modulates activity of growth hormone, ensures proper proportions Testosterone/estrogen - promote adolescent growth spurts, end growth by inducing epiphyseal plate closure; excesses or deficits of any hormones cause abnormal skeletal growth Bone Homeostasis - Recycle 5-7% of bone mass each week Spongy bone replaced ~ every 3-4 years Compact bone replaced ~ every 10 years