Deeper Insights Abnormal curves (p. 168) Anatomical Position (p. 197) Skeletal System– Gross Anatomy (Ch. 7 & 8) Human Anatomy lecture (Visit the Ossuary in Sedlec for a true appreciation of skeletal gross anatomy: http://www.ludd.luth.se/users/silver_p/kutna.html) I. Divisions & bone types A. Axial Skeleton– 80 bones (Fig. 7.1) Skull, ossicles, vertebrae, thorax, hyoid B. Appendicular Skeleton – 126 bones pectoral girdle 4 upper limb 60 pelvic girdle 2 lower limb 60 C. Bone types - sutural (Wormian) bones (Fig. 7.6) -- form along skull sutures - sesamoid bones: form within tendons ” seed-like” Ex.: patella (“kneecap”) II. Vertebral column A. Bones 33 vertebrae (26 pieces) 7 12 5 5 4 cervical thoracic lumbar sacral (fused = 1) coccygeal (fused = 1) B. Normal curves (Fig. 7.19) Primary (1o) thoracic & pelvic (sacral) – present in fetus Secondary (2o) cervical & lumbar – develop as child holds up head, trunk -- Sketch – Functions: -- facilitate upright posture -- dissipate shock C. Abnormal curves – Insight 7.3 & Fig. 7.21 1. scoliosis – abnormal lateral curvature 2. kyphosis – excessive anterior curvature (usually thoracic) 3. lordosis – excessive posterior curvature (usually lumbar) D. Each individual vertebra has 7 processes (Fig. 7.22) spinous & transverse = leverage superior & inferior articular = articulation --Sketch -- E. Intervertebral joints – between processes: synovial, planar – between bodies: cartilaginous, symphysis intervertebral disc- Fig.7.22 anulus fibrosus fibrocartilage; strong attachment nucleus pulposus absorb shock herniated disc - Fig. 7.36 III. Girdle/limb comparison Pectoral/upper limb 4 separate bones (2 clavicles & 2 scapulae) -- thin & light -- designed to maximize range of manipulation Pelvic/lower limb 2 coxal (hip) bones (each originally 3 bones, now fused) -- thick & heavy -- designed for weight-bearing and locomotion IV. Sexual differences (Table 8.1; Fig. 8.9) A. most obvious is in the pelvis (“basin”) = pelvic girdle + sacrum & coccyx (2 ossa coxae) (text differs) B. Why? Facilitate childbirth V. Arches of the foot (Fig. 8.16) A. Arches formed by bone, maintained by muscles & ligaments lateral longitudinal arch medial longitudinal arch transverse arch B. Functions: – distribute body weight (each foot forms a half-dome) – absorb shock VI. Aging --Sizes & shapes obviously change during life Ex.: mandible “baby face” “toothless grin”