## **Core Concept**
The question involves congenital anomalies of the larynx and hyoid bone, which are structures in the neck. These anomalies are likely related to developmental issues during embryogenesis. Understanding the embryological origins of these structures is crucial.
## **Why the Correct Answer is Right**
The development of the larynx and hyoid bone is closely related to the **third and fourth pharyngeal arches**. The greater cornuae (corners) of the hyoid bone develop from the second pharyngeal arch (hyoid arch), but the body and lesser cornuae of the hyoid bone, as well as the laryngeal cartilages (including the thyroid cartilage which forms the main part of the larynx), develop from the **third and fourth pharyngeal arches**. The absence of the greater cornuae and the inferior part of the hyoid bone suggests a developmental issue with the **third pharyngeal arch**, as it contributes to the formation of these structures.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because the **first pharyngeal arch** primarily contributes to the formation of the jaw, portions of the external ear, and associated muscles. It is not directly involved in the development of the larynx or the majority of the hyoid bone.
- **Option B:** This option is incorrect because, although the **second pharyngeal arch** (hyoid arch) does give rise to the stapes bone, styloid process, stylohyoid ligament, and the lesser horn (cornu) and upper part of the hyoid bone, the greater cornuae and the specific structures mentioned are not primarily derived from this arch.
- **Option D:** This option is incorrect because the **fourth pharyngeal arch** contributes to laryngeal development but specifically, the **third pharyngeal arch** is more closely associated with the development of the greater cornuae and inferior part of the hyoid bone.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that congenital anomalies of the neck, such as those described, can often be associated with specific syndromes or developmental disorders. The **third pharyngeal arch** derivatives include the common carotid arteries, internal carotid arteries, and parts of the hyoid bone, making its developmental failure critical in head and neck embryology.
## **Correct Answer:** C.
Free Medical MCQs Β· NEET PG Β· USMLE Β· AIIMS
Access thousands of free MCQs, ebooks and daily exams.
By signing in you agree to our Privacy Policy.