The endocrine and nervous systems have common functions such as internal communication and body regulation functions. The two systems are capable of slow and fast reactions to stimuli. The nervous system sends electrical impulses to each part of the body to regulate bodily functions while the endocrine system uses chemical signals to control bodily functions. The response to the stimulus for the nervous system is local while for the endocrine system it is widely diffused. White blood cells, or leukocytes, function within our bodies as a line of defense against infections. There are two types, granulocytes and agranulocytes: three granulocytes are basophils, eosinophils and neutrophils while the two agranulocytes are lymphocytes and monocytes. Whenever an infection occurs, whether bacterial or viral, there will be an increase in the number of white blood cells in a white blood cell count differential test. Neutrophils are most abundant in bacterial infections to perform phagocytosis on invading bacteria. The tricuspid, pulmonary, mitral, and aortic valves of the human heart control the flow of blood from one chamber to another and prevent the backflow of blood. The heart can experience problems such as stenosis or regurgitation if the heart is not working properly. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay The endocrine system and nervous system are important when it comes to the body's internal communication. These two systems share common functions with each other but also have fundamental differences in their mechanisms of action. They have common chemicals, examples such as dopamine and norepinephrine, which act as both hormones and neurotransmitters. The two systems also have similarities in how their messengers will affect target cells. Both work together through regulation, where neurons can trigger the secretion of hormones and hormones stimulate or inhibit neurons. On the other hand of the mechanisms of the endocrine and nervous systems, there are also several key differences. The endocrine system is able to communicate through hormones while the nervous system has electrical impulses and related neurotransmitters. The endocrine system releases hormones throughout the body through the distribution of hormones in the bloodstream, allowing for widespread effects. Neurotransmitters are released into the synapses of target cells within the body and have local effects in those specific target cells. Hormones generally react to stimuli slowly, taking anywhere from a few seconds to days, and continue to react even after the initial stimulus has stopped. Neurotransmitters react quickly and take no more than a few seconds to do so, stopping once the stimulus is stopped. Leukocytes, also known as white blood cells, provide protection from infectious microorganisms and pathogens. The five types of leukocytes are neutrophils, basophils, eosinophils, monocytes, and lymphocytes (Opentax, 2013). Neutrophils are the most abundant of the five, aggressive when against antibacterial cells. When affected by bacterial infection, neutrophils have elevated white blood cell counts, as these types of leukocytes are attracted to areas that have infection and inflammation. They act by phagocytosis, that's where they will digest the bacteria they encounter. Eosinophils are common when there is a parasitic infection while basophils help with neutrophil attraction and anticoagulation. Neutrophils will have easier access to the infection with the help of basophils. Lymphocytes are important when it comes to infectious diseases as they can produce an immune response while monocytes are helpful-2249217