Body systems & senses

Question

What Physiological factors contribute to incresed heart rate with increased activity? asking because i have a presentation in which i am going in depth with heart rate. i already know about the factors physical factors and other common factors to increase the heart rate. but if you know in detail on the hormonal factors which i have trouble understanding when we are active. James

Answer

<P>Dear James,</P> <P>Thank you for submitting your question to AskNSDL. We apologize for the delay. It appears that a specialist wasn't able to find time to respond to your question.</P> <P>I'm a librarian and looked for free, authoritative Internet resources that would provide information on this topic. I used Google, <A href=http://www.google.com">http://www.google.com</A>, and searched for the following string of terms: "heart rate" "sympathetic nervous system" hormone.</P> <P>* Chapter 39 - Endocrine System.&nbsp; "Biology Web - Human Biology," Clinton Community College (New York). Notes outline how the endocrine and nervous systems work together. Chapter highlights the roles of the hypothalamus, pituitary, and thyroid glands, as well as the adrenal medulla in controlling heart rate. For example, it states that the Adrenal Medulla secretes epinephrine and norepinephrine that "simulates the fight- or- flight response of the sympathetic nervous system. It results in a faster heart rate, faster blood flow, and dilated airways to facilitate oxygen flow to the lungs."<BR><A href=http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Endocrine%20System/endocrin.htm">http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Endocrine%20System/endocrin.htm</A></P> <P>* Biology II: Anatomy and Physiology: Chapter 51, Section 2, Endocrine Glands - Diagram and outline of the Endocrine System and its functions.<BR><A href=http://www.sirinet.net/~jgjohnso/endoreview.html">http://www.sirinet.net/~jgjohnso/endoreview.html</A>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </P> <P>* "SYMPATHOINHIBITION AND CHRONIC HEART FAILURE: FOCUS ON THE a2 ADRENERGIC RECEPTOR" by Irene Gavras, MD, Haralambos Gavras, MD, FRCP - Expert article from on SNS-Web: Advances in the Role of Sympathetic Nervous System in Cardiovascular Medicine. There is a section on the Neuroendocrine aspects of heart failure.<BR><A href=http://www.sns-web.org/pages/advances/08/article.asp">http://www.sns-web.org/pages/advances/08/article.asp</A> </P> <P>James, you didn't specify whether or not you were interested in human heart rate or other species. The following article provides a brief explanation of heart rate in horses and the physiological factors associated with it.</P> <P>*&nbsp; "Stress Management for Equine Athletes": Fact Sheet 716 by Karyn Malinowski, Ph.D., Dean of Outreach &amp; Extension Programs, Equine Science Center, Cook College, New Jersey Agricultural Experiment Station. New Brunswick, NJ. September 2004. - See paragraph 5 (Excerpt below):<BR><A href=http://www.equineww.com/hs/de/stman.html">http://www.equineww.com/hs/de/stman.html</A></P> <P>Paragraph 5 Excerpt: "When a horse is stressed, the first component of the endocrine response to be activated is the sympathetic nervous system, which potentiates the release of the catecholamines epinephrine and norepinephrine. Catecholamines mediate the classic fight-or-flight response, increasing heart rate, blood pressure, and respiration rate. During severe or chronic stress, the second arm of the stress response is activated (hypothalamic-pituitary-adrenal axis). Initially, sympathetic activation of the hypothalamus causes the release of Corticotropic Releasing Factor (CRF) which potentiates, at the level of the pituitary gland, the release of Adrenocorticotropic Hormone (ACTH). ACTH causes the release of glucocorticoids from the adrenal gland. The primary glucocorticoid secreted in horses is cortisol. Cortisol acts to assist the animal in relieving stress by increasing glucose metabolism to provide energy which enables the horse to escape from the stress."</P> <P>The resources at your library will also provide more information on this topic.</P> <P>If you would still like a response from an expert, please resubmit your question. We will do what we can to help you out.&nbsp; We are sorry for not responding sooner.</P> <P>Best wishes,<BR>Joyce W.<BR>AskNSDL staff<BR></P> http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Endocrine%20System/endocrin.htm http://www.sirinet.net/~jgjohnso/endoreview.html http://www.sns-web.org/pages/advances/08/article.asp http://www.equineww.com/hs/de/stman.html endocrine system<BR>heart rate<BR>hormones<BR>physiology http://vrd.askvrd.org/services/answerschema.xml