APPENDICULAR SKELETON

BONES TO KNOW 2

REVIEW

a—scaphoidb—lunatec—triquetrald—pisiform

a—hamate b—capitatec—trapeziumd—trapezoid

a—calcaneusb—talusc—naviculard—cuboide—intermediate cuneiformf—lateral cuneiformg—medial cuneiform

f

g

Pectoral Girdles (Shoulder Girdles)

Figure 7.22a

Clavicles (Collarbones)

Figure 7.22b, c

Scapulae (Shoulder Blades)

Figure 7.22d, e

Humerus of the Arm

Figure 7.23

Bones of the Forearm

Figure 7.24

Hand

Figure 7.26a

Pelvic Girdle• Formed by 2 hip bones (ossa coxae). • These are large and heavy bones attached

securely to the axial skeleton.• The sockets (Acetabulums) that connect the

thigh bones are deep and heavily reinforced by ligaments.

• Most important function is: bearing the total weight of the upper body.

• Reproductive organs, urinary bladder, and parts of the large intestine lie within.

Hip Bones• Each hip bone is formed by the fusion of 3

bones: ilium, ischium, and the pubis.

• Ilium- forms most of hip bone. When you rest your hands on your hips they are on your alae (wing like projection) – Iliac crest important for intramuscular

injection sites.

Hip Bones• Ischium- sit down bone

– Greater sciatic notch: allows blood and the large sciatic nerve to pass from pelvis to thigh. Buttocks Injections should be far away from here.

• Pubis- pubic bone– Obturator foramen: opening that allows blood

vessels and nerves to pass into anterior thigh.– Pubic Symphysis: Pubic bones of each hip

fuse to form cartilaginous joint

Pelvic Girdle (Hip)

Figure 7.27a

obturator foramen

Pelvis: Lateral View

Figure 7.27b

Ilium: Medial View

Figure 7.27c

Comparison of Male and Female Pelvic Structure

Characteristic Female Male

Bone thickness Lighter, thinner, and smootherHeavier, thicker, and more prominent markings

Pubic arch/angle 80˚–90˚ 50˚–60˚

Acetabula Small; farther apart Large; closer together

SacrumWider, shorter; sacral curvature is accentuated

Narrow, longer; sacral promontory more ventral

Coccyx More movable; straighterLess movable; curves ventrally

Image from Table 7.4

Comparison of Male and Female Pelvic Structure

Female Male

Thigh

• Femur- heaviest and strongest bone

• Neck of femur is a common fracture site, especially in old age.

• Head of femur articulates with the acetabulum of the hip bone

Femur

Figure 7.28b

Leg bones

• Two bones: Tibia and Fibia• Connected by interosseous membrane• Tibia= shinbone, larger and more medial

– Medial and lateral condyles articulate with femur.

– Kneecap ligaments attach to tibial tuberosity

• Fibula– Takes no part in forming the knee joint.– Lateral malleous forms outer part of ankle

Figure 7.29

Tibia and Fibula

Foot

• Composed of: tarsals, metatarsals, and phalanges.

• 2 important functions:– Support our weight– Propel our bodies forward when we walk or

run.

Bones of feet

• Tarsals- ankle bones– 7 bones total

• Metatarsals- soles of the foot– 5 total

• Phalanges- bones of the toes– 14 total (3 per toe except for the greater toe

which only has 2)

Tarsals

• Body weight is carried mostly by the two largest: Calcaneus (heel bone) and talus (ankle bone)

• Last 5 are: Navicular, medial cuneiform, intermediate cuneiform, lateral cuneiform, and cuboid.

Metatarsus and Phalanges

Figure 7.31a

Tarsus

Figure 7.31b, c

Arches of Foot

• 3 strong arches: 2 longitudinal and 1 transverse.

• Ligaments which connect foot bones and tendons of foot muscles help hold foot bones firmly in arched position.

• Weak arches= fallen arches or flat feet