Human Anatomy: Lower Extremity and Pelvic Girdle

What is the primary function of the lower extremity in the human body?

• Digestion

• Weight bearing and gait

• Circulation

• Respiration

Answer explanation

The primary function of the lower extremity is weight bearing and gait, enabling humans to stand, walk, run, and maintain balance. This is essential for mobility and support of the body's weight.

Which bones form the pelvic girdle?

• Femur, tibia, fibula

• Ilium, ischium, pubis

• Radius, ulna, humerus

• Scapula, clavicle, sternum

Answer explanation

The pelvic girdle is formed by three bones: the ilium, ischium, and pubis. These bones connect the spine to the lower limbs, providing support and structure to the pelvis.

What is the name of the joint that connects the ilium to the sacrum?

• Acetabulum

• Sacroiliac joint

• Pubic symphysis

• Iliac crest

Answer explanation

The sacroiliac joint is the connection between the ilium and the sacrum, allowing for limited movement and providing stability to the pelvis. The other options do not represent this specific joint.

What is the function of the acetabulum in the pelvic girdle?

• It supports the weight of the upper body during sitting.

• It connects the ilium to the sacrum.

• It receives the head of the thigh bone.

• It joins the two pubic bones.

Answer explanation

The acetabulum is a cup-shaped socket in the pelvic girdle that receives the head of the thigh bone (femur), forming the hip joint. This allows for a wide range of motion in the leg.

Which part of the femur is most vulnerable to fractures?

• Shaft

• Head

• Neck

• Trochanter

Answer explanation

The neck of the femur is the most vulnerable part to fractures due to its anatomical position and the stress it endures during weight-bearing activities. Fractures here are common, especially in older adults.

What is the longest and strongest bone in the human body?

• Tibia

• Femur

• Humerus

• Radius

Answer explanation

The femur is the longest and strongest bone in the human body, supporting the weight of the body and allowing for movement. It is located in the thigh and connects the hip to the knee.

The pelvic girdle consists of which of the following structures?

• Coxal bone, sacrum, coccyx, and associated joints and features

• Femur, tibia, fibula, and patella

• Scapula, clavicle, humerus, and associated joints

• Radius, ulna, carpals, and metacarpals

Answer explanation

The pelvic girdle is made up of the coxal bones (hip bones), sacrum, coccyx, and their associated joints and features, which support the weight of the upper body and connect the spine to the lower limbs.

Which part of the femur is most vulnerable to fracture despite being the strongest bone in the body?

• Head

• Neck

• Shaft

• Greater trochanter

Answer explanation

The neck of the femur is the most vulnerable to fracture due to its anatomical position and the stress it endures during weight-bearing activities, despite the femur being the strongest bone in the body.

What is the primary function of the fibula in the lower leg?

• To bear the weight of the body

• To provide motion capability

• To serve as a site for muscle attachments

• To protect the knee joint

Answer explanation

The fibula primarily serves as a site for muscle attachments, providing stability and support to the lower leg. Unlike the tibia, it does not bear significant weight, making muscle attachment its main function.

Which bone in the lower leg bears most of the weight of the body?

• Fibula

• Tibia

• Patella

• Femur

Answer explanation

The tibia, also known as the shinbone, is the larger and stronger of the two bones in the lower leg. It bears most of the body's weight, while the fibula serves mainly for muscle attachment and stability.