Advanced Appendicular Skeleton Quiz Challenge

The phalanges in the human body are categorized into proximal, middle, and distal phalanx based on their position in the fingers and toes.

The coxal bone, also known as the hip bone, is composed of the ilium, ischium, and pubis along with additional features like Obturator foramen, acetabulum, greater sciatic notch, ischial spine, lesser, sciatic notch, pubic crest, iliac crest.

The patella, also known as the kneecap, consists of the base at the top and the apex at the bottom.

Ribs are composed of different parts such as the head, neck, tubercle, body, and sternal end, each serving specific functions in the human body's skeletal structure.

The sternum consists of the jugular notch, clavicular notch, manubrium, body, and xiphoid process, forming the breastbone in the human body.

The humerus is the upper arm’s long bone connecting the shoulder and elbow. Its head fits into the glenoid cavity, while the greater and lesser tubercles anchor rotator cuff muscles. The shaft has the deltoid tuberosity for muscle attachment, and distal structures like the epicondyles, capitulum, and trochlea articulate with forearm bones. These landmarks facilitate flexion, extension, and rotation at the elbow joint.

The radius extends from the lateral side of the elbow to the wrist, forming part of the forearm. Its neck supports the head that rotates with the ulna, while the radial tuberosity anchors the biceps tendon. The styloid process stabilizes the wrist joint, and the ulnar notch allows articulation with the ulna. These features ensure effective pronation and supination of the forearm.

The ulna is the medial bone of the forearm and functions as a stabilizing structure. Its olecranon and coronoid processes form the hinge joint of the elbow with the humerus. The trochlear notch allows flexion and extension, while the styloid process contributes to wrist stability. Its shape ensures mechanical efficiency for forearm leverage during lifting and gripping motions.

The coxal bone (hip bone) is formed by three fused parts — ilium, ischium, and pubis — that meet at the acetabulum, which articulates with the femur. The obturator foramen, crests, and notches support muscular attachments and weight distribution. This bone forms part of the pelvic girdle, bearing upper body weight and transmitting forces from the trunk to the lower limbs.

The patella, or kneecap, is a sesamoid bone embedded within the quadriceps tendon. It has a flat base superiorly and a pointed apex inferiorly. Its position protects the knee joint and improves leverage for the quadriceps muscle during extension. The patella also reduces friction between tendons and bones, enhancing mechanical efficiency during walking, running, and jumping activities.

The femur, the body’s longest and strongest bone, connects the pelvis to the tibia. Its head fits into the acetabulum, forming the hip joint. The neck, trochanters, and linea aspera serve as muscle attachment points, while the condyles and patellar surface articulate with the tibia and patella. These structures collectively enable weight-bearing and powerful locomotor movement.

The fibula, located on the lateral side of the leg, provides stability rather than weight support. Its head articulates with the tibia, while the lateral malleolus forms the outer ankle prominence. The inferior articular surface connects with the talus, aiding ankle stability. The fibula serves as an attachment for muscles and ligaments that maintain balance and foot motion control.

The tibia, or shinbone, is the main weight-bearing bone of the lower leg. Its medial and lateral condyles articulate with the femur, forming the knee joint. The tibial tuberosity anchors the patellar ligament, while the medial malleolus stabilizes the ankle. Its thick structure efficiently transfers body weight from the femur to the foot, ensuring stability during walking and standing.

The human foot is composed of tarsal, metatarsal, and phalangeal bones. The tarsals include the calcaneus, talus, navicular, cuboid, and cuneiforms, which form the foot’s arches and provide balance. These bones distribute body weight across the foot, maintain posture, and absorb shock during movement, making them essential for upright locomotion and mechanical efficiency.