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:
Gastric glands neck cells" that produce mucus. This is thought to be different from the mucus produced by the gastric mucosa. Fundic glands found in the fundus and also in the body have another two cell types–gastric chief cells and parietal cells (oxyntic)). The chief cells are found in the basal regions of the gland and release a zymogen – pepsinogen, a precursor to pepsin. The parietal cells ("parietal" means "relating to a wall") are found in the walls of the tubes. The parietal cells secrete hydrochloric acid–the main component of gastric acid. This needs to be readily available for the stomach