The heart utilizes electrochemical signals to control the rate at which it contracts. It accomplishes this using bundles of "pacemaker cells" whose signals maintain an internal rhythm independent of the body. However, at rest the rhythm it maintains is slightly faster than what is ordinarily required. The neuroendocrine system usually dampens this rate, but it can elevate it as well using electrical or chemical signals (during exercise or stress).
The neuroendocrine ( neuro-nerve; endocrine-hormone) system is a compilation of inputs from the nervous system as well as glands throughout the body that secrete chemicals. Both usually work together to account for transient or even chronic changes in the body. Using nerve signals or hormones, the neuroendocrine system changes cell activities that alter the diameter of blood vessels, the heart's rate and strength of contraction, and even the amount of fluid the body retains.
No comments:
Post a Comment