Step 2 should be sensory neurons send electrical signals to the brain
Step 3 brain learns information about the environment
Step 4 brain sends electrical signals to the muscles
In 1885 Virchow said that all cells exist from pre-existing cells
Answer:
C. is unstable, with a short half life
Explanation:
Paracrine hormones are the hormones that act on neighboring cells only. These hormones or chemicals are largely unstable and have a brief life as do not visit the distantly placed target cells. For instance, somatostatin is secreted by D cells of the pancreas. It acts in a paracrine manner and inhibits the discharge of hormones from the neighboring beta and alpha cell.
Likewise, one of the functions of unstable NO gas is to serve as a vasodilator. It is released by epithelium cells and serves to dilate arterioles and relax precapillary sphincters. Then it is degraded.
2. sodium ion that has lost an electron
