Correct Option
The correct option isPituitary
Explanation
The endocrine system comprises various glands that secrete hormones directly into the bloodstream to regulate physiological functions. Among these, the pituitary gland holds a central regulatory position due to its influence over other endocrine glands.
Detailed Analysis
- Pituitary Gland (Master Gland): Located in the sella turcica of the sphenoid bone at the base of the brain, the pituitary gland secretes "tropic hormones" (e.g., TSH, ACTH, FSH, LH). These hormones stimulate and regulate the activity of other endocrine glands such as the thyroid, adrenal cortex, and gonads. Due to this controlling function, it is designated as the "master gland."
- Thyroid Gland: Located in the neck, it primarily regulates basal metabolic rate (BMR) through the secretion of thyroxine. It is regulated by the pituitary gland.
- Adrenal Gland: Located above the kidneys, it secretes hormones like cortisol and adrenaline involved in stress responses and metabolic regulation. Its cortical function is regulated by the pituitary.
- Pancreas: A composite gland (both exocrine and endocrine) that regulates blood glucose levels via insulin and glucagon. It is not considered the master gland.
While the pituitary is called the master gland, it is itself controlled by the hypothalamus, which serves as the link between the nervous system and the endocrine system.
Key Takeaway
The pituitary gland is termed the "master gland" because it produces hormones that control the secretion and functioning of other major endocrine glands in the body.