Question

97\. Match the two columns and select the correct option from the codes given below. \(\begin{array}{ll}\text { Types of } & \text { Bones }\end{array}\) synovial joint involved A. Ball and socket (i) Carpal and metacarpal of thumb B. Hinge (ii) Atlas and axis C. Pivot (iii) Frontal and parietal D. Saddle (iv) Knee (v) Humerus and pectoral girdle (a) \(A-(v), B-(i v), C-(i i), D-(i)\) (b) \(A-(1), B-(i i), C-(i v), D-(v)\) (c) \(A-(v), B-(i v), C-(i i), D-(i)\) (d) \(A-(i), B-(i i), C-(v), D-(i v)\)

Short answer

A-(v), B-(iv), C-(ii), D-(i), the correct answer is (a).

Step-by-step solution

- Identify Types of Synovial Joints

Recognize the characteristics of ball and socket, hinge, pivot, and saddle joints. A ball and socket joint allows for radial movement in almost all directions; a hinge joint allows for a bending motion similar to a door hinge; a pivot joint allows for rotational motion around a single axis; a saddle joint allows for movement back and forth and side to side, but not rotational movement.

- Match Joints to Examples

With the definitions in mind, match each joint to its corresponding example. The ball and socket joint (A) is exemplified by the humerus and pectoral girdle (v), the hinge joint (B) is found in the knee (iv), the pivot joint (C) can be seen between the atlas and axis (ii), and the saddle joint (D) is represented by the carpal and metacarpal of the thumb (i).

- Select the Correct Option

Review the given options and select the one that matches the correct pairs identified in Step 2. The answer should correctly match all the types of synovial joints to their corresponding bones.

Key concepts

Ball and Socket Joint

Imagine being able to move your arm in almost any direction; this incredible range of motion is thanks to the ball and socket joint. Found in our hips and shoulders, this joint consists of a spherical end of one bone (the ball) fitting into a cup-like socket of another bone. This structure allows for movement around multiple axes, which means you can swing your arms in circles and your legs can stride forward, sideways, and even twist slightly.

Think of the shoulder joint, where the humerus (the upper arm bone) meets the pectoral girdle. This is a perfect example of a ball and socket joint in action, providing the mobility needed for various activities from throwing a ball to reaching for the top shelf. For students trying to understand the exercise, remember the ball and socket joint as the all-rounder, offering a wide range of movement that other joints cannot.

Hinge Joint

Just like the hinges on a door that allow it to swing open and closed, our hinge joints enable our body parts to move in one plane. These joints are formed between two or more bones where the convex end of one bone fits into the concave end of the other. This design restricts movement to just bending and straightening, which is technically called flexion and extension.

A classic example is the knee joint, where the femur (thigh bone) connects with the tibia (shinbone). It's the hinge movement that lets us walk, run, sit, and kick. For those studying from the exercise, it's easiest to associate the hinge joint with actions similar to opening and closing a book - a singular, straightforward motion.

Pivot Joint

Turning your head to look around is so natural that we rarely consider the complexity behind it. The pivot joint makes such rotation possible. It consists of the rounded end of one bone fitting into a ring formed by another bone and ligament, allowing rotation around a central axis.

Take the joint between the atlas and axis bones of your neck; these two vertebrae work together as a pivot joint to enable the head to move from side to side, saying 'no' in body language. For students visualizing the solution to the exercise, imagine a rotating door: the pivot joint permits a similar rotational motion but within the body's structure.

Saddle Joint

The saddle joint is an interesting and fairly unique joint that allows for versatile movement, just not to the extent of the ball and socket joint. This joint is shaped like a saddle, where one bone is concave at one end and convex at the other, interlocking with another bone that has the opposite congruence.

An exemplar of the saddle joint is found at the base of the thumb—the carpal and metacarpal bones. These allow for the back-and-forth and side-to-side movements of the thumb, enabling the grasping and manipulating of objects. When grappling with the exercise's concepts, students can think of the saddle joint as providing the dexterity needed for intricate tasks like writing or typing.