Problem 136 - Objective Biology for NEET

Question

Which of the following pairs is correctly matched? (a) Hinge joint Between vertebrae (b) Gliding joint Between carpal and metacarpal of thumb (c) Cartilaginous joint \(-\) between carpels (d) Fibrous joint \(=\) Flat skull bones

Step-by-Step Solution

Answer

The correctly matched pairs are option (b) Gliding joint between carpal and metacarpal of thumb, and option (d) Fibrous joint = flat skull bones.

Step 1: Analysing option (a)

Hinge joint is typically found in elbows and knees, not between vertebrae. Therefore, option (a) is not correctly matched.

Step 2: Analysing option (b)

Gliding joint is found where the bones meet at flat or slightly curved faces and allows gliding or sliding movements, such as between the carpal and metacarpal of thumb. Therefore, option (b) is correctly matched.

Step 3: Analysing option (c)

Cartilaginous joints are those that are connected entirely by cartilage, such as those between the ribs and the sternum. They do not exist between carpels. Therefore, option (c) is not correctly matched.

Step 4: Analysing option (d)

Fibrous joint is a type of structure in the human body that lies between bones keeping them close together. They occur in the flat skull bones. Therefore, option (d) is correctly matched.

Key Concepts

Hinge Joint

Hinge joints are a fascinating part of human anatomy. These joints allow movement similar to the opening and closing of a door. They are simple, yet very effective in providing uniaxial movement, which means they allow movement in one plane only.

• Key examples include the elbow and knee joints, providing the motion needed for activities like walking, running, and picking up objects.
• Hinges joints are supported by strong ligaments, which prevent the bones from sliding sideways.

The design of the hinge joint allows it to support a considerable amount of force and pressure. This is very important for activities that require powerful extension and flexion, such as jumping or lifting. Unlike some joints, hinge joints do not allow rotation.

Gliding Joint

Gliding joints are unique because they allow bones to move past each other in a smooth motion. This movement does not involve rotation or angling at the joint but rather sliding motions across the bone surfaces.

• These joints are primarily found in the wrists (carpals) and ankles (tarsals), as well as between the carpal and metacarpal of the thumb.
• The flat or slightly curved surfaces of these bones meet to facilitate the sliding movement.

This sliding capability is crucial for small adjustments that enable complex movements in the hands and feet. This joint helps with flexibility and dexterity, making it possible to perform tasks that require intricate finger movements or to maintain balance during walking.

Cartilaginous Joint

Cartilaginous joints are defined by the presence of cartilage between the bones, allowing for slight movement. One common example is the joints between vertebrae in the spine, which must remain stable enough to protect the spinal cord but flexible enough to accommodate movement.

• These joints allow for limited movement and serve as shock absorbers, cushioning the bones from impact.
• Cartilage, a durable and flexible material, bridges the gaps, providing stability and support.

These joints are essential in places where motion needs to be restricted but still exist. Other examples include the ribs' connection to the sternum, ensuring the ribcage can expand with each breath.

Fibrous Joint

Fibrous joints are rigid and do not allow much movement between the connected bones. They are connected entirely by connective tissues known as fibrous tissue, as seen in the structure of flat skull bones.

• This type of joint provides stability and protection, crucial for safeguarding delicate organs such as the brain.
• The tight connection defends the interior structures from external forces.

In infants, some of these joints contain softer tissues, allowing the skull to pass through the birth canal. Over time, they harden into the bone, providing a robust frame that lets the brain grow during childhood. Fibrous joints are perfect where strength and protection are preferred over flexibility.