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