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The appendicular skeleton. Appendicular skelton + skeletal muscles= movement. Bones of the appendicular skeleton. 2 pectoral girdles Clavicles, scapulae 2 upper extremities Pelvic girdle Coxae (hip bones) 2 lower extremities. Some important external features of bones.
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The appendicular skeleton Appendicular skelton + skeletal muscles= movement
Bones of the appendicular skeleton • 2 pectoral girdles • Clavicles, scapulae • 2 upper extremities • Pelvic girdle • Coxae (hip bones) • 2 lower extremities
Some important external features of bones • Processes where tendons and ligaments attach • Trochanter, tuberosity- large and small • Tubercle- rounded • Crest- ridge • Spine- pointed • Processes formed at articulations • Head, condyle, facet • Depressions and openings • Fossa, sulcus, foramen, sinus
The clavicle • Joint between clavicle and sternum is only direct connection between axial skeleton, shoulder girdle • Easily fractured
Scapula (shoulder blade) • Glenoid cavity articulates with head of humerus to form shoulder joint • Acromion forms tip of shoulder; articulates with clavice • Coracoid process is an attachment site
Upper limb • Arm (humerus) • Glenohumeral joint • Distal end articulates with radius and ulna • Forearm • Radius (lateral), ulna (medial) • Fibrous membrane connects the two
Wrist and hand • 8 carpals, 5 metacarpals, 14 phalanges • Carpal tunnel formed by space between hamate and pisiform; scaphoid and trapezium • Median nerve and flexor tendons pass through it
Pelvic girdle is much more massive than pectoral girdle • Pelvis: two coxae, sacrum, coccyx • Coxa formed by ileum, ischium and pubis • Obturator foramen is largest in skeleton
Male and female pelves wider Female pelvis is lighter and shallower Wider outlet
Pectoral vs pelvic girdle • Pectoral does not articulate directly with vertebrae • Pectoral girdle provides more mobility than strength • Pelvic girdle provides more strength than mobility
Lower limb • Femur is longest, strongest, heaviest bone • Articulates with pelvis at acetabulum • Articulates with tibia and fibula at distal end • Tibia and fibula form lower leg • Fibula is attachment site; does not bear weight or help form knee joint • Fibrous membrane between the two
Bones of ankle and foot • Seven tarsals; talus articulates with tibia and fibula • Standing, most weight is supported by calcaneus • Muscles attached to calcaneus by Achilles tendon • Metatarsal bones carry the rest
Arches of the foot • Longitudinal arch • Begins at calcaneus, extends to heads of metatarsals • Transverse arch • Formed by tarsals and bases of metatarsals • Normally ball of foot carries 40% of weight and heel 60%
Bone and joint disorders • Bone structure and remodeling is affected by: • Age (osteopoenia) • Physical stress • Hormone levels • Rates of calcium and phosphate absorption and excretion • Genetic and environmental factors
Diagnosing skeletal disorders • Limitation of movement • Joint involvement (mono-or polyarthritic?) • Inflammation • Sounds (bony crepitus)- grating sounds • Abnormal bone deposits around fractures or joints • Abnormal posture
Congenital disorders • Osteogenesis imperfecta- lack of bone collagen fibers • Marfan’s syndrome- connective tissue disorder affects heart as well • Achondroplasia-epiphyseal plates are replaced by bone • Clubfoot(congenital talipes equinovarus) abnormal muscle development • Cleft palate • Spina bifida
infections • Osteomyelitis usually caused by S. aureus • Paget’s disease apparently caused by virus
Malnutrition and bone disorders scurvy rickets
Secondary disorders can also affect skeleton • Endocrine (giantism) • Autoimmune (rheumatoid arthitis) • Gout (digestive) • How do joints faciliate bone movement?