Light micrograph of the human thyroid gland,showing the functional units of thyroid follicles,each surrounded by a single layer of cuboidal epithelial cells. The follicles vary in size according to their states of synthetic or secretory activity; some contain stored hormones in the form of thyroid colloid,which appears red. Two types of hormones are produced: 1) The iodine- containing hormones tri-iodothyronine (T3) and thyroxine (T4): T4 is converted to T3 in circulation - T3 regulates basal metabolic growth. 2) calcitonin,which regulates calcium levels in the blood. Magnification: x100 at 35mm size | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Michler, Astrid & Hans-Frieder |
Bildgröße: | 4972 px × 3240 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |