Question:medium
The 8th and 9th rib costal cartilages form which type of joint with each other?
The 8th and 9th rib costal cartilages form which type of joint with each other?
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What kind of joint links neighbouring lower costal cartilages and allows gliding?
Updated On: Jun 23, 2026
- Costochondral joint
- Interchondral joint
- Synovial joint
- Costovertebral joint
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: First identify which surfaces are meeting. The eighth and ninth costal cartilages contact each other along their margins, so this is a cartilage-to-cartilage (interchondral) contact, not rib-to-cartilage or rib-to-vertebra.
Step 2: Now recall the histological character of these interchondral contacts. The cartilages of ribs $6$ through $10$ articulate by small synovial joints that permit slight gliding during breathing.
Step 3: The question asks for the $type$ of joint, and that type is synovial. The costochondral junction (rib to its cartilage) is a primary cartilaginous joint and the costovertebral joint (rib to spine) is a separate synovial articulation, so neither fits this pairing.
Step 4: Putting the location (interchondral) together with the asked-for type (synovial) gives option c as the answer.
\[\boxed{\text{Synovial joint}}\]
Step 2: Now recall the histological character of these interchondral contacts. The cartilages of ribs $6$ through $10$ articulate by small synovial joints that permit slight gliding during breathing.
Step 3: The question asks for the $type$ of joint, and that type is synovial. The costochondral junction (rib to its cartilage) is a primary cartilaginous joint and the costovertebral joint (rib to spine) is a separate synovial articulation, so neither fits this pairing.
Step 4: Putting the location (interchondral) together with the asked-for type (synovial) gives option c as the answer.
\[\boxed{\text{Synovial joint}}\]
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