(N/A) The pituitary gland is often called the master endocrine gland because it secretes hormones that control and coordinate the activities of most other endocrine glands.
$(b)$ The pancreas acts as a heterocrine (mixed) gland. It secretes pancreatic juice containing enzymes into the small intestine for digestion,and it also secretes hormones like insulin and glucagon directly into the blood to regulate blood sugar levels.
$(c)$ The adrenal glands are known as glands of emergency because they secrete the hormone adrenaline (epinephrine) during stressful situations. Adrenaline prepares the body for 'fight or flight' by increasing heart rate,breathing rate,and blood flow to skeletal muscles,allowing the body to respond rapidly to emergencies.