The correct option is (a).
Explanation
The pituitary gland is a critical component of the endocrine system, often referred to as the "master gland." It plays a central role in regulating vital body functions and general wellbeing by secreting hormones that control other endocrine glands.
- Statement 1 is Correct: The pituitary gland is a small, pea-sized gland located in a bony cavity called the sella turcica at the base of the brain. It is anatomically attached to the hypothalamus by a stalk (infundibulum).
- Statement 2 is Incorrect: Insulin is secreted by the pancreas (specifically by the beta cells of the Islets of Langerhans), not the pituitary gland. Insulin is essential for regulating blood glucose levels. The pituitary gland secretes hormones such as Growth Hormone (GH), Thyroid Stimulating Hormone (TSH), and Adrenocorticotropic Hormone (ACTH).
- Statement 3 is Incorrect: The pituitary gland does not function independently; it is regulated by the hypothalamus. Furthermore, it significantly influences other endocrine glands (such as the thyroid, adrenal glands, and gonads) by releasing stimulating hormones. Therefore, the statement that it does not influence other glands is factually wrong.
Key Takeaway:
The pituitary gland is located at the base of the brain and regulates other endocrine glands (Master Gland), whereas insulin is a metabolic hormone secreted by the pancreas.