What is a 'Defined-Benefit Plan'. A defined-benefit plan is a retirement plan that an employer sponsors, where employee benefits are computed using a formula that considers factors, such as length of employment and salary history. The company administers portfolio management and investment risk for the plan.
The distinction between neuropeptide and peptide hormone has to do with the cell types that release and respond to the molecule; neuropeptides are secreted from neuronal cells (primarily neurons but also glia for some peptides) and signal to neighboring cells (primarily neurons).oth neuropeptides and peptide hormones are synthesized by the same sets of enzymes, which include prohormone convertases and carboxypeptidases that selectively cleave the peptide precursor at specific processing sites to generate the bioactive peptides.
This hormone production system is regulated by a negative feedback loop so that when the levels of the thyroid hormones, thyroxine and triiodothyronine increase, they prevent the release of both thyrotropin-releasing hormone and thyroid stimulating hormone.he production and release of thyroid hormones, thyroxine and triiodothyronine, is controlled by a feedback loop system which involves the hypothalamus in the brain and the pituitary and thyroid glands.