Problem 134 - Objective Biology for NEET

Question

Sutural joints are found between (a) Parietals of skull (b) Humerus and radius-ulna (c) Glenoid cavity and pectoral girdle (d) Thumb and metatarsal

Step-by-Step Solution

Answer

(a) Parietals of skull is the correct answer as sutural joints are found between the bones of the skull.

Step 1: Understanding Sutural Joints

Sutural joints, also known as suture joints or synarthroses, are immovable joints only found in the skull where the bones are held together by short fibers. These rigid joints between the bones of the skull provide strength and stability.

Step 2: Identifying Correct Option

With the understanding of sutural joints location, identify the correct option. In this case where it's found 'Between the parietals of the skull' matches the definition of sutural joints. Thus, the correct answer is (a) Parietals of skull.

Key Concepts

Skull Anatomy

The human skull is a complex structure with multiple bones that are intricately connected to form a protective case for the brain.
These bones are divided into two main categories: the cranial bones and the facial bones.
The cranial bones enclose and protect the brain, while the facial bones form the structure of the face.

• There are eight major cranial bones: one frontal, two parietals, two temporals, one occipital, one sphenoid, and one ethmoid bone.
• These bones are joined together by immovable joints, known as sutures, that provide protection and give shape to the skull.
• Each bone in the skull has specific anatomical landmarks and serves a particular function.

The parietal bones, specifically, are situated on either side of the skull forming the top and sides of the cranial cavity.
They are notable for their role in housing the brain and providing head shape.

Synarthroses

Synarthroses are a classification of joints characterized by their immovability.
Unlike other joint types, synarthroses do not allow for any movement between the joining bones.

• Sutural joints, which are a type of synarthrosis, are specifically found in the skull.
• This stability is crucial for the protection of the brain and the structural integrity of the skull.
• There are several types of synarthroses, but sutures are unique due to their location exclusively in the skull.

The fibers that connect the bones in syncarthroses are short, fibrous tissues.
These tissues help endure force, distribute stress, and maintain the skull's rigid structure.

Cranial Sutures

Cranial sutures are a type of fibrous joint that connects the bones of the skull.
They resemble seams or stitches and appear as deep grooves between bones.

• Some well-known cranial sutures include the coronal suture (between the frontal and parietal bones), the sagittal suture (in between the two parietal bones), and the lambdoid suture (between the occipital and parietal bones).
• These sutures play a crucial role during birth, allowing overlapping of skull bones for a safer passage through the birth canal.
• In adults, these sutures become slightly ossified allowing no movement, which is vital for brain protection.

Over time, sutures allow for the gradual growth of the skull, accommodating brain growth from infancy into adolescence.
Understanding cranial sutures not only gives insight into skull anatomy but is also fundamental in fields such as medicine and anthropology.