01 / Location & anatomical relationships
Usually on the back of the thyroid gland.
02 / Structure & organization
Usually four small glands lie near the posterior thyroid, although number and position vary. Chief cells secrete parathyroid hormone in response to calcium-related signals. Its actions involve kidney, bone and vitamin D pathways.
03 / Function
Their hormone helps control the amount of calcium in your blood.
04 / Mechanism
These small glands release parathyroid hormone when blood calcium needs adjustment. The hormone influences bones, kidneys and indirectly the gut to help restore balance. Calcium is important for muscle and nerve activity as well as bones.
Working together: endocrine system
Hormones travel in the blood to their target cells. Different hormones help guide growth, energy use and changes during puberty.
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Connect structure with function
Parathyroid glands are separate endocrine organs, despite their name and proximity to the thyroid. Their central regulatory role concerns extracellular calcium balance.
Check your understanding
Locate the parathyroid glands in relation to its neighbors. Explain how the structural features described above support its function, then distinguish it from a nearby structure with a different role.
Keep learning
Continue with OpenStax Anatomy and Physiology for system-level study. This atlas is educational and has not undergone independent medical peer review.