Chitinous rings supporting tracheae are called

Options

A. Atria
B. Taenidia
C. Ctenidia
D. Lamellae

Answer

To solve the question "Chitinous rings supporting tracheae are called," we will follow these steps:

### Step 1: Understand the Structure of Trachea
The trachea is a tube-like structure that is part of the respiratory system in certain organisms, particularly insects. It is important to know that the trachea has a specific structure that includes multiple layers.

**Hint:** Remember that the trachea has three main layers that contribute to its function and support.

### Step 2: Identify the Layers of the Trachea
The trachea is composed of three layers:
1. An outer basement membrane
2. A middle layer of cell-thick epithelium
3. An inner lining called the intima

**Hint:** Focus on the inner lining, as it is crucial for the formation of the chitinous rings.

### Step 3: Recognize the Role of Intima
The intima is the inner layer of the trachea, and it is made of chitin. This layer is responsible for producing spiral thickening or rings that provide structural support to the trachea.

**Hint:** Think about what material is used to create the supportive structures in the trachea.

### Step 4: Identify the Chitinous Rings
The chitinous rings that support the trachea are specifically referred to as "tracheal spirals" or "tracheal rings." In this context, they are called "tenidia."

**Hint:** Look for the term that directly refers to the supportive rings made of chitin in the tracheal structure.

### Step 5: Choose the Correct Option
Given the options: atria, tenidia, synidia, lamellae, the correct answer is **tenidia**. These are the chitinous rings that prevent the collapse of the trachea.

**Hint:** Remember to select the option that directly relates to the structural support of the trachea.

### Final Answer
The correct answer is **tenidia**.