Hypothalamic–pituitary–somatotropic axis with growth hormone deficiency or Laron syndrome ( insensitivity) show symptoms like short stature, dwarfism and obesity, but are also protected from some forms of cancer. Conversely, acromegaly and gigantism are conditions of GH and IGF-1 excess usually due to a pituitary tumor, and are characterized by overgrowth and tall stature. Hypothalamic–pituitary–somatotropic axis The hypothalamic–pituitary–somatotropic axis (HPS axis), or hypothalamic–pituitary–somatic axis, also known as the hypothalamic–pituitary–growth axis, is a hypothalamic–pituitary axis which includes the secretion of growth hormone (GH; somatotropin) from the somatotropes of the pituitary gland into the circulation and the subsequent stimulation of insulin-like growth factor 1 (IGF-1;
Head and neck anatomy through the circulatory system and by direct connection of neurons. Also, within the cranium, the pineal gland, which attaches to the thalamus, controls the body's 24-hour rhythms circadian rhythm through the release of melatonin. The pituitary gland secretes hormones that directly impact the body as well as hormones that indirectly control body functions because they activate other endocrine glands, such as the adrenal cortex (ACTH) and the thyroid gland (TSH). These two glands when stimulated by pituitary hormones then release their own hormones. The pituitary gland has two lobes, the anterior lobe and the posterior lobe. The anterior lobe secretes: