Adrenal gland
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which produces steroid hormones and an inner medulla. The adrenal cortex itself is divided into three zones: the zona glomerulosa, the zona fasciculata and the zona reticularis.
Parathyroid chief cell
The parathyroid gland is part of the endocrine system. Most individuals display four parathyroid glands adjacent to the thyroid gland anterior in the neck. The chief cells are organized as dense cords surrounding the capillaries in the parathyroid. The thyroid gland and parathyroid gland are closely tied together in the calcium pathway. The thyroid gland secretes three hormones: T3, T4, and calcitonin. When the calcium level in the blood is too high, calcitonin is secreted, and the level is lowered. Calcitonin does this by depositing calcium in the bones. PTH works inversely from calcitonin. When the level of calcium in the blood is too low, PTH is released, and the level of calcium is raised. Calcium is released from the bone storage. This trigger also retains calcium from the urine, and alerts the intestines to absorb more calcium from ingested nutrients. Too much of either hormone can be an indicator of disease.