Endocrine System

Insulin, Glucagon, Somatostatin

The pancreas produces insulin (from beta cells), glucagon (from alpha cells), and somatostatin (from delta cells) in the islets of Langerhans. Thyroxine is from thyroid and adrenaline is from adrenal medulla.

Cortex produces glucocorticoids, Medulla produces adrenaline

The adrenal cortex produces glucocorticoids (like cortisol) and mineralocorticoids (like aldosterone). The adrenal medulla produces adrenaline and noradrenaline. Insulin is produced by pancreas.

Iodine deficiency

Simple goitre is caused by iodine deficiency. When there's not enough iodine to make thyroxine, the thyroid gland enlarges trying to produce more hormone, causing a swelling in the neck.

Oxytocin

Oxytocin from the posterior pituitary causes milk ejection (let-down) and also stimulates uterine contractions during childbirth. Prolactin stimulates milk production, not ejection.