Appendicular Skeleton

Appendicular Skeleton

• 126 bones – suspended by girdles from axial skeleton

• Designed for movement• Pectoral girdle – 4 bones• Upper extremity -Arm – 1 bone

- forearm – 2 bones - hand = wrist, palm & fingers – 27 bones [each]

• Pelvic Girdle – 2 bones

• Lower Extremity – leg – 1 bone

- lower leg – 2 bones

- foot = ankle, instep & toes – 26 bones [each ]

- Patella – 2 bones

*Pelvic or Hip Girdle:

•Attaches the lower extremity to the axial skeleton

•Provides support for body weight

Hip / Coxal bones [ ossa coxae, innominate bones]

Ilium – ASIS, PSIS

Ischium - tuberosity

Pubis - rami

Symphysis pubis

Obturator foramen

Acetabulum

Lower Extremity

• Leg [thigh] – femurHeadFovea capitisNeckTrochanters –

greater/lesserCondyles –

medial/lateralEpicondyles

Lower Extremity

*Leg – region between knee and ankle

• Fibula – lateral bone• Tibia – medial bone

Malleolus

Condyles – medial/lateral

Tibial tuberosity

Patella [kneecap] a flat, triangular sesamoid bone

Enclosed within the quadriceps tendon

Ankle or Tarsus

Contains 7 tarsal bones

Calcaneous = heel bone

Talus

Cuboid

Navicular

Cuneiforms – lateral, intermediate & medial

Foot• Metatarsals – not

named, but numbered 1 – 5 starting at medial side

• Toes – phalanges or digits: 3 bones [proximal, distal & middle] for each toe, except big [great] toe which has 2 [no middle phalanx]

Pectoral or Shoulder Girdle•Clavicle [collarbone] – ‘S’ shaped bone * most frequently fx’d bone of body

•Scapula [shoulder blade] – thin, flat, triangular bone.

Acromion

Spine

Coracoid process

Gleniod fossa/cavity

Upper Extremity• Arm [brachium]

humerusHeadTubercles – greater/lesserEpicondlyes –

medial/lateralOlecranon fossaCapitulumTrochlea

Upper Extremity

*forearm – region between elbow and wrist

• Ulna

Olecranon process• Radius

head

Styloid process

Wrist or Carpus• Contains 8 carpal bonesBound tightly by

ligaments Arranged in 2 rowsScaphoid TrapeziumLunate TrapezoidTriquetral CapitatePisiform Hamate

Hand

•Metarcarpals – not named, but numbered 1-5 starting on lateral [thumb] side

•Fingers – phalanges or digits: 3 bones [proximal, distal & middle] for each finger, except thumb, which has 2 [ no middle phalanx]