Bones of the Lower Limbs and Pelvic Girdle

Bones of the Lower Limbs

• The lower limb consists of the femur (thigh), tibia and fibula (leg), tarsals (ankle), metatarsals (foot), and phalanges (toes)

Pelvic Girdle

• Composed of two hip bones, sacrum, and coccyx
• Hip bones unite anteriorly with each other at symphysis pubis
• Articulates posteriorly with the sacrum
• Formed by hip bones, sacrum, and coccyx
• Divided into two regions: true (lesser) pelvis and false (greater) pelvis

Hip Bone

• Composed of ilium, ischium, and pubis
• Acetabulum is a deep hemispherical socket on the lateral pelvic surface

Sex Difference of the Pelvis

• Pelvic inlet is oval in female and heart-shaped in male
• Ischial spines don't project medially in the pelvis in female
• Pubic angle is 80-90 in female and 50-60 in male

The Lower Limb

• Carries the entire weight of the erect body
• Bones of the lower limb are thicker and stronger than those of the upper limb
• Divided into three segments: thigh, leg, and foot

Femur

• Is the largest and strongest bone of the body

Appendicular Skeleton

• The primary function is movement
• Includes bones of the upper and lower limbs
• Girdles attach the limbs to the axial skeleton

Skeleton of the Upper Limb

• Consists of the shoulder girdle, arm, forearm, and bones of the hand

Pectoral Girdle

• Consists of two clavicles and two scapulae
• Provides attachment for many muscles that move the upper limb
• Girdle is very light and upper limbs are mobile
• Only clavicle articulates with the axial skeleton
• Socket of the shoulder joint (glenoid cavity) is shallow

Clavicle

• Provides attachment for muscles
• Holds the scapulae and arms laterally
• Transmits compression forces from the upper limbs to the axial skeleton

Scapula

• Has three surfaces: costal, dorsal, and spinous
• Dorsal surface is divided by the spine into supra-spinatus and infra-spinatus fossa
• Angles of the scapula include superior, lateral, and inferior angles

Humerus

• Is the largest bone in the upper limb
• Articulates superiorly with the scapula and inferiorly with the radius and ulna
• Has upper and lower ends and a shaft

Patella

• Triangular sesamoid bone
• Imbedded in the tendon that secures the quadriceps muscles
• Protects the knee anteriorly

Leg

• Refers to the region of the lower limb between the knee and the ankle
• Composed of the tibia and fibula
• Tibia articulates with the femur at the superior end and forms the knee joint
• Tibia articulates with the talus at the inferior end and forms the ankle joint
• Fibula does not contribute to the knee joint but stabilizes the ankle joint

Fibula

• The fibula has upper and lower ends and a shaft
• The upper end has a styloid process, head, neck, and tibial notch

Bones of the Foot

• Consist of tarsals, metatarsals, and phalanges
• There are 7 tarsal bones, 5 metatarsal bones, and 14 phalanges
• First metatarsal supports body weight

This quiz covers the bones of the lower limbs, including the femur, tibia, fibula, tarsals, metatarsals, and phalanges, as well as the bones of the pelvic girdle, including the hip bones, sacrum, and coccyx.