Which of the following is NOT a difference between fibrous joints?
A suture are made of bone tissue and syndesmoses are made of fibrous connective tissue
B sutures are only found in the skull and syndesmoses are found in many parts of the body sutures are immovabe and syndesmoses range from immovable to slightly movable
C some sutures fuse completely during childhood and syndesmoses do not permanently fuse bones together
The correct answer and explanation is:
The correct answer is A: sutures are made of bone tissue and syndesmoses are made of fibrous connective tissue.
Explanation:
Fibrous joints are classified based on the type of connective tissue that binds the bones together. The three main types of fibrous joints are sutures, syndesmoses, and gomphoses.
- Sutures: These are immovable joints found primarily between the bones of the skull. Sutures are made of dense fibrous connective tissue, not bone tissue. They allow minimal to no movement, which is crucial for protecting the brain during development. In infants and children, the sutures are flexible, allowing for growth of the skull, but as a person ages, sutures fuse, becoming synostoses (bony fusion) in adulthood.
- Syndesmoses: These are fibrous joints where bones are connected by a ligament or an interosseous membrane. They allow for slight movement, making them somewhat flexible. An example of syndesmosis is the connection between the tibia and fibula in the leg. This type of joint ranges from immovable to slightly movable, depending on the length of the connecting fibers.
The key distinction is that sutural joints (sutures) are made of fibrous tissue, not bone tissue. The role of sutures is to provide rigidity and protection to the skull, and they are immovable until they fuse with age. On the other hand, syndesmoses involve a fibrous connective tissue ligament that can allow for slight movement between bones, such as the tibia and fibula. Therefore, the claim in option A that sutures are made of bone tissue is incorrect.
To summarize, option A is not a true difference, because sutures are composed of fibrous tissue, not bone, unlike syndesmoses, which involve fibrous connective tissue.