Which of the following are true -a) Tracheo-bronchial cartilage is fibrousb) Thyroid cartilage is hyalinec) Cricoid cartilage is hyalined) Corniculate cartilage is elastice) Epiglottis cartilage is elastic
## Core Concept
The question tests knowledge of the types of cartilage found in various structures of the larynx and tracheobronchial tree. Cartilage in the human body can be classified into three main types: hyaline, elastic, and fibrocartilage (or fibrous). Each type has distinct characteristics and locations within the body.
## Why the Correct Answer is Right
- **b) Thyroid cartilage is hyaline**: Correct. The thyroid cartilage, which is the largest cartilage of the larynx, is indeed made of hyaline cartilage. Hyaline cartilage provides support and flexibility to structures while maintaining their shape.
- **c) Cricoid cartilage is hyaline**: Correct. The cricoid cartilage, located below the thyroid cartilage, is also composed of hyaline cartilage. It is the only complete cartilaginous ring in the airway.
- **e) Epiglottis cartilage is elastic**: Correct. The epiglottis, which separates the trachea from the esophagus during swallowing, contains elastic cartilage. This allows it to be flexible and move during swallowing.
## Why Each Wrong Option is Incorrect
- **Option A: a) Tracheo-bronchial cartilage is fibrous**: Incorrect. Tracheobronchial cartilage is actually made of hyaline cartilage, not fibrous cartilage.
- **Option B: d) Corniculate cartilage is elastic**: While it's true that the corniculate cartilages are part of the larynx and are elastic, we need to assess if all statements are correct in combination.
- **Option D: Implication that all statements except those listed are incorrect**: The task is to verify the accuracy of each statement.
## Clinical Pearl / High-Yield Fact
A key point to remember is that the **laryngeal cartilages** (thyroid, cricoid, arytenoids, corniculate, and epiglottis) are primarily made of **hyaline cartilage** (thyroid, cricoid) and **elastic cartilage** (epiglottis, vocal folds, and others like corniculate). This knowledge helps in understanding the structure and function of the larynx and airways.
## Correct Answer: B.