FILGRASTIM, G-CSF (fil GRA stim) is a granulocyte colony-stimulating factor that stimulates the growth of neutrophils, a type of white blood cell (WBC) important in the body's fight against infection.
The hypothalamus, a part of the brain, is responsible for many hormones. Understanding these brainy hormones will help you take control of your body and your health. The hypothalamus produces hormones that control the production of hormones in the pituitary gland.
The pituitary gland itself is regulated by another gland, known as the hypothalamus (shown in the picture above in light blue). The hypothalamus is part of the brain and produces TSH Releasing Hormone (TRH) which tells the pituitary gland to stimulate the thyroid gland (release TSH). One might imagine the hypothalamus as the person who regulates the thermostat since it tells the pituitary gland at what level the thyroid should be set.