The right answer is an underactive pituitary gland
The stunting of children or adolescents is sometimes due to a deficiency of the growth hormone naturally produced by the body. It is then sufficient to give them this substance, in synthetic form, so that they start to "grow" again.
During their visit to the pediatrician who regularly measures them, some children are smaller than the growth standards established for their age and gender. They suffer from growth retar-dation that can come from a deficit, total or partial, of somatotropin, called growth hormone. This biological substance is well named. Naturally secreted by the pituitary (a gland located in the brain), it is indeed essential for children and adolescents to grow well. But his role is not limited to that. It also allows their bones to acquire optimal density and participate in the development of their muscles. Those who are deprived of it remain small.
This kind of modeling is known as (D) simulation. A computer program is used to simulate an environment, in this case, the zoo. Instead of having to do an actual experiment which harms real animals, a simulation is done to cut costs and avoid using live samples.
Gap junctions form pores that connect adjacent cells. In this way signaling molecules, ions and other substances can pass through the pore to the adjacent cell. This type of cell junctions are important in cardiac muscle responses, in brain signaling, during childbirth, etc.
