Which of the following endocrine structure synthesizes and secretes releasing and inhibiting hormones to control another endocrine structure ?

Options

A. Master of master gland
B. Master gland
C. Supra renal gland
D. Both (a) and (c)

Answer

To solve the question, "Which of the following endocrine structures synthesizes and secretes releasing and inhibiting hormones to control another endocrine structure?", we will follow these steps:

### Step 1: Understand the Role of Endocrine Structures
The endocrine system is composed of glands that secrete hormones directly into the bloodstream to regulate various bodily functions. Some glands have the ability to control the secretion of other glands through specific hormones.

**Hint:** Look for the gland that has a regulatory role over other glands.

### Step 2: Identify the Glands Mentioned
The question mentions several glands, including:
- Pituitary gland
- Hypothalamus
- Suprarenal (adrenal) gland

**Hint:** Focus on the functions of each gland to determine which one controls others.

### Step 3: Analyze the Pituitary Gland
The pituitary gland is known as the "master gland" because it regulates the activity of other endocrine glands by secreting hormones like TSH (Thyroid Stimulating Hormone) and ACTH (Adrenocorticotropic Hormone).

**Hint:** Consider whether the pituitary gland has the ability to both stimulate and inhibit the secretion of hormones.

### Step 4: Examine the Hypothalamus
The hypothalamus is often referred to as the "master of the master gland" because it controls the pituitary gland. It synthesizes and secretes releasing hormones (like GnRH) that stimulate the pituitary gland and inhibiting hormones (like somatostatin) that can inhibit the secretion of certain hormones from the pituitary.

**Hint:** Think about which gland has the dual role of releasing and inhibiting hormones.

### Step 5: Consider the Suprarenal (Adrenal) Gland
The suprarenal gland, or adrenal gland, produces hormones like cortisol and adrenaline but does not control other endocrine glands. It primarily functions independently.

**Hint:** Eliminate options that do not have a regulatory role over other glands.

### Step 6: Conclusion
Based on the analysis, the hypothalamus is the correct answer as it synthesizes and secretes both releasing and inhibiting hormones that control the pituitary gland, which in turn affects other endocrine structures.

**Final Answer:** The correct answer is the **hypothalamus**.