Delete Content. A plasma membrane is permeable to specific molecules that a cell needs. Transport proteins in the cell membrane allow for selective passage of specific molecules from the external environment. Each transport protein is specific to a certian molecule (indicated by matching colors).
The pancreas contains cells which release both insulin and glucagon. The endocrine system consists of a number of different glands which secrete hormones that dictate how cells and organs behave.
Counterregulatory Hormones. Hormones that work against the action of insulin, raising blood glucose levels in response to hypoglycemia (low blood sugar). The main counterregulatory hormones are glucagon, epinephrine (also known as adrenaline), cortisol, and growth hormone. People who donât have diabetes have a number of defense mechanisms against hypoglycemia.