`T_(3)` and `T_(4)` hormones are synthesised by

Options

A. follicles
B. stromal tissue
C. isthmus
D. Both (1) and (3)

Answer

To answer the question "T3 and T4 hormones are synthesized by," we will follow these steps:

### Step 1: Identify the hormones
- T3 stands for triiodothyronine.
- T4 stands for tetraiodothyronine, also known as thyroxine.

### Step 2: Locate the gland responsible for synthesis
- T3 and T4 hormones are synthesized by the thyroid gland.

### Step 3: Understand the structure of the thyroid gland
- The thyroid gland is a butterfly-shaped organ located in the anterior part of the neck, around the larynx and trachea.
- It consists of two lobes connected by a narrow band of tissue called the isthmus.

### Step 4: Identify the specific cells responsible for hormone production
- The thyroid gland contains follicular cells that are responsible for the production of T3 and T4 hormones.

### Step 5: Evaluate the options provided
- Option 1: Follicles - Correct, as T3 and T4 are synthesized by follicular cells in the thyroid gland.
- Option 2: Stromal tissue - Incorrect, as it only supports the follicles and does not produce hormones.
- Option 3: Isthmus - Incorrect, as it connects the lobes but does not synthesize hormones.
- Option 4: Both option 1 and option 3 - Incorrect, since only option 1 is correct.

### Conclusion
- The correct answer is that T3 and T4 hormones are synthesized by the follicles of the thyroid gland.

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