1 Think of this as being like the skin of the avocado. Although not strictly a part of the adrenal glands themselves, the primary function of this layer is to enclose and protect each of the adrenals.  The Cortex. You might compare this layer to the flesh of an avocado.
The average lifespan for a hammy is about 2-3 years and they are very sweet!! The average life span for a hamster in general is about 2-4 years, but different breeds live differents spans. Teddy bears: 2-3 yrs. Syrian: 1 1/2- 3 yrs. Cambells, russians & other dwarfs: 1-3 yrs.
However, this is assuming that the hamster does not get ill and dies naturally of old age. It is quite common for hamsters to develop fatal illness between 18 months and 2 years old. Obviously all hamsters are different and some may live longer than this or die at a younger age for no apparent reason. I have found that Roborovski hamsters seem to be much hardier than other species; most of my robos have died through old age rather than illness.