The appendicular skeleton consist of

126 bones

• The pectoral (shoulder) girdle
• Upper extremities
• Pelvic (hip) girdle
• Lower extremities

The pectoral (shoulder) girdle

Attach the bones of the upper extremities to the axial skeleton

Clavicle and scapula

Comprises each of the two pectoral girdles; form a framework that allows the shoulder joint to be freely movable with great range of motion

The most frequently broken bone in the body is the

Clavicle

A fractured clavicle is common because

This bone transmits forces from the upper extremity to the trunk

The scapulae articulates with other bones arteriorly, but are held in place

Posteriorly only by complex shoulder and back musculature

Upper limb (extremity) contains

30 bones (60 total)

• Humerus
• Ulna
• Radius
• Carpal (8)
• Metacarpals (5)
• Phalanges (14)

The longest & largest bone in the upper extremity; the region where it is located is referred to anatomically as the arm

Humerus

The most frequently dislocated bone in the body

Head of the humerus

Ulna and radius

Lie parallel to one another

Ulna on pinky side; radius on thumb side

Carpal bones

Bound together by ligaments, comprise the wrist

Medial to lateral:

Metacarpals bone

Contained in the palm of each hand

Medial to lateral:

Phalanges

Three in each finger & two in each thumb

The pelvic (hip) girdle consists

Two hipbones (coxal bones) & provides a strong and stable support for the lower extremities, on which the weight of the body is carried

Each hipbone (coxal bone) is composed of three separate bones at birth

• Illium
• Pubis
• Ischium

Illium, pubis, and ischium eventually fuse at a depression and forms the socket for the hip joint

Acetabulum

Together with the sacrum and coccyx, the two hipbones (coxal bones) form

The pelvis

The greater (false) and the lesser (true) pelvis are

Anatomical subdivisions of the basin-like structure

Pelvimetry

Measurement of the dimensions of the divisions of the pelvic cavity, particularly those of the lesser (true) pelvis of the female (labor and delivery)

The lower extremities are composed of

60 bones (30 in each)

The femur

• Thighbone
• Longest and heaviest bone in the body
• Just distal to the pelvic girdle
• Large and obvious markings represent points of attachment of many large thigh muscles

The patella

• Kneecap
• Sesamoid bone
• Lies anterior to the knee joint
• Increases the leverage of the tendon of the quadriceps femoris muscle
• Maintains the position of the tendon when the knee is flexed

The tibia

• Shinbone
• Parallel with the fibula
• Larger, medial, and bears the major portion of the weight of the leg to the fibula

The fibula

• Parallel bone with the tibia
• Smaller, lateral, compared to tibia

Seven tarsals bones constitute

The ankle and share the weight associated with walking

Five metatarsal bones

Contained in the foot

The arrangement of phalanges in the toes is the same as that described for

The fingers and thumb--14 bones in each foot/hand

The bones of the foot are arranged in two non-rigid arches that enable the foot to

• Support the weight of the body
• Provide and ideal distribution of body weight over the hard and soft tissues of the foot
• Provide leverage while walking

Flatfoot and clawfoot

Caused by decline or elevation, respectively of the medial longitudinal arches

Bunion

Deformity of the great toe

Male bones are generally larger and heavier then

Female

Male joint surfaces tend to be larger than

Female

Muscle attachment points are more well defined in males than

Females

A number of anatomical differences exist between the pelvic girdles of females and those of males, primarily related to

The need for a larger pelvic outlet in females to facilitate childbirth