Question

The joint of femur with pelvic girdle is (a) hinge joint (b) non-movable joint (c) pivot joint (d) ball and socket joint.

Short answer

The joint of the femur with the pelvic girdle is a ball and socket joint.

Step-by-step solution

Identify the Joint

The joint formed at the articulation of the femur with the pelvic girdle is known as the hip joint.

Understand Joint Types

There are several types of joints characterized by their movements. A hinge joint allows movement in one plane, a pivot joint allows rotation around a single axis, a ball and socket joint allows multi-axial movement, and a non-movable joint does not allow any movement.

Match the Joint with Its Type

Considering the nature of the human hip joint, which allows for movement in multiple axes including rotation, flexion, extension, abduction, and adduction, it can be categorized as a ball and socket joint.

Key concepts

Types of Joints

Our bodies are incredible structures, with joints serving as the essential points of connection between bones. These joints are broadly classified based on how they move. Hinge joints, like those in your fingers, allow movement in one direction, similar to a door hinge. Pivot joints enable rotational movement, as seen in the neck. Ball and socket joints offer a wide range of movement in all directions, and you’ll find a great example of this in the shoulder. Finally, there are non-movable joints, such as the sutures in the skull, which don’t move at all.

Understanding these types helps us recognize the elaborate ways our bodies function and how different joints contribute to our daily activities like walking, writing, and turning our heads.

Ball and Socket Joint

Picture a baseball snugly fitting in a glove; that's essentially the concept behind a ball and socket joint. It consists of a spherical end of one bone (the ball) fitting into a cup-like depression of another bone (the socket), allowing the joint to move in multiple directions. This structure affords us a tremendous range of motion. Think of swiveling your arm to throw a ball or gyrating your hips to dance — such freedom of movement is thanks to this joint's design, which allows for rotations, swinging movements, and even combinations of these.

Joint Movement

The action that takes place at joints is called joint movement. It's not just about swinging a limb; it involves specific terms such as flexion (bending a joint), extension (straightening a joint), abduction (moving away from the body's midline), and adduction (moving towards the body's midline). These movements are integral to our daily life, to perform tasks such as picking up objects, running, or even writing. Just like a complex mechanical device, our joints combine these movements to accomplish fluid motion.

Hip Joint Anatomy

Diving deeper into the structure of the hip joint reveals a perfect demonstration of the ball and socket architecture. The ball is the rounded head of the femur, or thigh bone, and the socket is a concave depression called the acetabulum in the pelvic girdle. This setup not only allows for a wide range of movements but also supports the weight of the upper body, providing both mobility and stability. The joint is enveloped by muscles, tendons, and ligaments that control the movements and secure the bones in place, all protected by a capsule filled with lubricating synovial fluid to ensure smooth, pain-free motion.