An immovable joint is called?

Appeared in: UPRVUNL - 2021

Explanation

Synarthrosis refers to an immovable joint where bones are united by fibrous tissue.
These joints lack a joint cavity and are designed for stability and protection.
A classic example is the sutures found between the bones of the skull.
Functionally, they are fixed and do not permit any significant movement.

Option A: Polyarthritis is a medical condition, not a structural or functional classification of a joint. It describes inflammation in multiple joints.
Option B: Amphiarthrosis refers to a slightly movable joint, not an immovable one. The bones are connected by cartilage.
Option D: Diarthrosis refers to a freely movable joint, which is the opposite of an immovable joint. These are also known as synovial joints.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Functional Classification of Joints as background academic context rather than a clinical decision trigger.
Understanding joint classification is fundamental for assessing mobility and diagnosing joint disorders. For example, arthritis primarily affects diarthrodial (freely movable) joints.
The immovability of synarthrodial joints, like the skull sutures, is critical for protecting vital organs. In infants, these sutures are slightly more flexible to allow for brain growth, a condition known as craniosynostosis if they fuse prematurely.
What if? - If a joint previously classified as an amphiarthrosis (slightly movable), like the pubic symphysis, becomes hypermobile after childbirth, it can lead to significant pain and instability, requiring physical therapy or a pelvic binder for support. This highlights how changes in joint mobility can cause clinical problems.

How to Approach the Question

This is a factual recall question that tests your knowledge of anatomical terminology.
First, identify the key term in the question: 'immovable joint'.
Next, recall the functional classifications of joints based on their degree of movement.
Evaluate each option: 'Polyarthritis' is a disease, 'Amphiarthrosis' means slightly movable, 'Synarthrosis' means immovable, and 'Diarthrosis' means freely movable.
Match the key term 'immovable' with the correct definition, which is 'Synarthrosis'.

Concept Tested & Keywords

Qaiyi4eH6U3cSfghy93-Fc

E6 Nursing Fundamentals Taylor p. 306-308

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 1196-1198

E6 Osteology InderbirSingh 5e p. 23-25

Practise the full UPRVUNL - 2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.