This work presents a Phenomenological Based Semiphysical Model (PBSM) of the human pancreas function in glucose homeostasis. The model focuses on demonstrating how change the flows of insulin and glucagon leaving the pancreas and going to the blood, according to the levels of glucose detected by the pancreas in the bloodstream. The model has an adequate fit with regarding available data from literature, including an adjustment factor to correct the measurements difference due to the point where glucose, insulin and glucagon are measured is different to the real point where these substances going to the bloodstream.