parathyroid gland. pth producing. primary lymphoid organ of the human

parathyroid anatomical structure human endocrine anatomy thyroid blood hormone medicine vector gland biology internal system organ parathormone body medical trachea triiodothyronine larynx health tyrosine science cartilage neck parathyrin thymus immune medulla cortex immunity tissue pituitary physiology lymphatic care disease immunology antigen t cell fibrous capsule lymphocyte cortical lymphoid chest development