Pelvic Girdle

Os Coxae (Hip Bone)

The pelvic girdle consists of two hip bones (os coxae), each formed by the fusion of three bones: the ilium, ischium, and pubis. These bones provide support for the lower limbs and protect pelvic organs.

• Ilium: The largest and most superior part of the hip bone.

  • Iliac crest: The superior border of the ilium, palpable on the lateral side of the hip.

• Ischium: The posteroinferior part of the hip bone.

  • Ischial spine: A pointed projection located between the greater and lesser sciatic notches.

• Pubis: The anteroinferior part of the hip bone.

  • Pubic symphysis: A cartilaginous joint uniting the left and right pubic bones.

• Obturator foramen: A large opening created by the ischium and pubis, allowing passage of nerves and blood vessels.

• Acetabulum: A deep socket that articulates with the head of the femur to form the hip joint.

Lower Extremity

The lower extremity consists of the femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges. Each bone has distinct anatomical landmarks important for movement and support.

Femur

The femur is the longest and strongest bone in the body, forming the thigh. It articulates proximally with the pelvis and distally with the tibia and patella.

• Head and neck: The rounded head fits into the acetabulum; the neck connects the head to the shaft.

• Greater trochanter: A large, lateral projection for muscle attachment.

• Lesser trochanter: A smaller, posteromedial projection for muscle attachment.

• Fovea: A small pit on the head for ligament attachment.

• Medial and lateral condyles: Rounded projections at the distal end that articulate with the tibia.

• Intercondylar fossa: A deep notch between the condyles on the posterior side.

• Patellar surface: Anterior area where the patella articulates with the femur.

Patella

The patella, or kneecap, is a sesamoid bone embedded in the quadriceps tendon. It protects the knee joint and improves leverage for thigh muscles.

• Base: The broad, superior end.

• Apex: The pointed, inferior end.

Tibia

The tibia, or shinbone, is the larger and medial bone of the lower leg. It bears most of the body's weight.

• Medial malleolus: The prominent bone on the inner side of the ankle.

Fibula

The fibula is the slender, lateral bone of the lower leg. It stabilizes the ankle and supports muscles of the lower leg.

• Lateral malleolus: The prominent bone on the outer side of the ankle.

Tarsals

The tarsals are seven bones in each foot that form the ankle and proximal foot. Each must be known by name:

• Talus

• Calcaneus

• Navicular

• Medial cuneiform

• Intermediate cuneiform

• Lateral cuneiform

• Cuboid

Metatarsals

There are five metatarsal bones in each foot, numbered I-V from medial (big toe) to lateral (little toe). They form the arch of the foot and provide attachment for muscles.

Phalanges (Foot)

Each foot has 14 phalanges: proximal, middle, and distal for toes II-V, and proximal and distal for the big toe (hallux). Each must be known by name and position.

Summary Table: Major Bones and Key Features

Additional info: Students should be able to identify each bone and its key features on anatomical models or diagrams, and distinguish left from right and anterior from posterior views where relevant.