Chapter 32, Problem 17A

Summary Introduction

Introduction:

A point where two bones meet or join is known as joints. Joints are classified on the basis of the structure and the movement they can allow. There are five types of joints in the human body. They are ball and socket, pivot, hinge, gilding and sutures.

Answer to Problem 17A

Correct answer:

Correct answer is option (c) elbow.

Explanation of Solution

Explanation/justification for the correct answer:

Option (c) elbow. Elbow is an example of a hinge type of joint in which the convex surface of one bone gets fits into the concave surface of another bone. Back and forth movement is possible due to these types of joints.

Explanation for incorrect answer:

Option (a) hip. The hip is an example of a ball and socket joint. In these types of joints, a ball-like structure of one bone fits into the cup-like depression of another bone. These types of joints provide the widest range of movement.

Option (b) vertebrae. Vertebrae is a combination of 33 small individual bones through which the spinal cord passes. Each vertebral is connected by an intervertebral disc made up of cartilages.

Option (d) skull. Skull is a combination of 22 bones that protects the brain. Bones in the skull have a suture type of joint. No movement is possible in the suture type of joints. Only the lower jaw bone doesn’t have a suture type of joint.

Conclusion

Option (c) elbow is a correct option because in elbow humerus is joined with the radius and ulna by the hinge type of joints and provides back and forth movement.