Brain natriuretic peptide (BNP), also known as B-type natriuretic peptide, is a hormone secreted by cardiomyocytes in the heart ventricles in response to stretching caused by increased ventricular blood volume. BNP is named as such because it was originally identified in extracts of pig brain.
How your bladder works. Your bladder is controlled by a complex system of nerves from your autonomic nervous system (parasympathetic and sympathetic), as well as by your spinal nervesare nerves that enter and exit the spinal cord, transmitting sensory and motor information to and from the brain.
There are two types of muscle that control the size of the iris: the iris sphincter, composed of circularly arranged muscle fibers, and the iris dilator, composed of radially arranged muscle fibers. The sphincter is innervated by the parasympathetic nervous system; the dilator by the sympathetic nervous system.