Transcript The Skeletal System: - North Seattle College

The Skeletal System:
The Appendicular Skeleton
I. Introduction
A. The appendicular skeleton includes the
bones of the upper and lower extremities
and the shoulder and hip girdles.
I. Introduction
B. The appendicular skeleton functions
primarily to facilitate movement.
II. Pectoral (Shoulder) Girdle
A. The pectoral girdle attaches the bones of
the upper limbs to the axial skeleton.
II. Pectoral (Shoulder) Girdle
1. The clavicle or collar bone lies
horizontally in the superior and anterior
part of the thorax and articulates with
the sternum and the scapula.
II. Pectoral Girdle Continue
The clavicle, one of the most frequently broken
bones in the body
II. Pectoral Girdle Continue
2. The scapula or shoulder blade
articulates with the clavicle and the
humerus.
II. Pectoral Girdle Continue
The scapulae is held in place posteriorly
only by complex shoulder and back
musculature.
III. Upper Limb
A. Each upper limb consists of 30 bones
including the humerus, ulna, radius,
carpals, metacarpals, and phalanges.
III. Upper Limb
1. The humerus is the longest and largest
bone of the upper limb.
III. Upper Limb
It articulates proximally with the scapula
at the glenohumeral joint, and
distally at the elbow with both the radius
and ulna.
III. Upper Limb Continue
2. The ulna is located on the medial
aspect of the foramen.
III. Upper Limb Continue
3. The radius is located on the lateral
aspect (thumb side) of the foramen.
III. Upper Limb Continue
 Falling on an outstretched arm may
create a Colle’s fracture, a fracture near
the distal end.
Upper Limb Continue
The radius and ulna articulate with the
humerus at the elbow joint, with each
other, and with three carpal bones.
Upper Limb Continue
4. Carpals, Metacarpal, Phalanges
Upper Limb Continue
The eight carpal bones, bound together by
ligaments, comprise the wrist.
Upper Limb Continue
 Because of the scant blood supply to the
scaphoid, scaphoid fractures may be
very slow to heal.
III. Upper Limb Continue
Five metacarpal bones are contained in
the palm of each hand.
III. Upper Limb Continue
Each hand contains 14 phalnges, three in
each finger and two in in each thumb.
IV. Pelvic Girdle
A. The pelvic (hip) girdle consists of two
hipbones (coxal bones) on which the
weight of the body is carried.
IV. Pelvic Girdle
 Each hipbone is composed of three
separate bones at birth:
1. Ilium
2. pubis
3. ischium.
IV. Pelvic Girdle
 These bones eventually fuse at a
depression called the acetabulum,
which forms the socket for the hip joint.
IV. Pelvic Girdle
 The ilium is the largest and articulates
(fuses) with the ischium and pubis.
IV. Pelvic Girdle
 The ischium is the inferior, posterior
portion of the hip bone.
IV. Pelvic Girdle
 The pubis is the anterior and inferior
part of the hip bone.
IV. Pelvic Girdle Continue
B. True or False Pelves
1. Together with the sacrum and coccyx,
the two hipbones form the pelvis.
IV. Pelvic Girdle Continue
2. The greater (false) and lesser (true)
pelvis are anatomicaly separated by a
plane at the pelvic brim.
V. Comparison of Male and Female
 Female and male pelvic girdles
differences are primarily related to the
need for a larger outlet in females to
facilitate childbirth.
V. Comparison of Female and Male
Pelves
 Male bones are larger and heavier than
those of the female
V. Comparison of Female and Male
Pelves
 Male’s joint surfaces also tend to be
larger.
V. Comparison of Female and Male
Pelves
 Muscle attachment points are more welldefined in the bones of a male than of a
female due to the larger size of the
muscles in males.
V. Comparison of Female and Male
Pelves
Iliac bones of male more vertical
V. Comparison of Female and Male
Pelves
Pelvic brim in male is heart shaped due to
prominence of the sacral promontary
V. Comparison of Female and Male
Pelves
Pelvic brim more oval in female
V. Comparison of Female and Male
Pelves
Pubic arch in male is under 90 degrees
V. Comparison of Female and Male
Pelves
Pubic arch in females over 90 degrees
VI. Comparison of Pectoral and
Pelvic Girdles
1. The pectoral girdle does not directly
articulate with the vertebral column; the
pelvic girdle does.
VI. Comparison of Pectoral and
Pelvic Girdles
2. The pectoral girdle sockets are shallow
and maximize movement
VI. Comparison of Pectoral and
Pelvic Girdles
3. Sockets of the pelvic girdle are deeper
and allow less movement.
VI. Comparison of Pectoral and
Pelvic Girdles
4. The structure of the pectoral girdle
offers more movement than strength
VI. Comparison of Pectoral and
Pelvic Girdles
5. The pelvic girdle, more strength than
movement.
VII. Lower Limb
A. Each lower extremity is composed of 30
bones, including the femur, tibia, fibula,
tarsals, metatarsals, and phalanges.
Femur
• The femur or thighbone is the largest,
heaviest, and strongest bone of the body.
Femur
• It articulates with the hip bone and the
tibia.
Patella
 The patella or kneecap is a sesamoid
bone located anterior to the knee joint
Patella
• Protects the knee joint
Patellofemoral stress syndrome
• Common knee problem in runners
Patellofemoral stress syndrome
• During normal flexion and extension of the
knee, the patella tracks up and down in
the patellar groove of the femur
Patellofemoral stress syndrome
 In this syndrome the patella also tracks
laterally, increasing the pressure on the
cartilage coating the underside of the
patella.
Tibia
 The tibia or shinbone is the larger,
medial, weight-bearing bone of the leg.
Fibula
 The fibula is parallel and lateral to the
tibia.
Tarsals
 Seven tarsal bones constitute the ankle
Metatarsals
 Five metatarsal bones are contained in
the foot.
Phalanges
 Fourteen bones in each foot.
Arches of the foot
• The bones of the foot are arranged in two
nonrigid arches that enable the foot to
support the weight of the body
Arches of the foot
 Provide an ideal distribution of body
weight over the hard and soft tissues
Arches of the foot
 Provide leverage while walking.
Arches of the foot
 The longitudinal arch has a medial and
lateral component.
Arches of the foot
 The transverse arch is perpendicular to
these arches.
VII. Lower Limb Continue
2. As a person ages, they tend to get
flattening of the longitudinal arches,
causing the foot to elongate.
Hip Fractures
 A break in the bones associated with the
hip joint.
Hip Fractures
 Often require surgical treatment
Hallux
 Called a bunion
Hallux
 The proximal phalanx of the great toe
deviates laterally
Hallux
 The first metatarsal deviates medially.