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

Pectoral girdle

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 Female pelvis is lighter and shallower wider 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?