When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Parasympathetic nervous system - Wikipedia

    en.wikipedia.org/wiki/Parasympathetic_nervous_system

    The vagus nerve plays a crucial role in heart rate regulation by modulating the response of sinoatrial node; vagal tone can be quantified by investigating heart rate modulation induced by vagal tone changes. As a general consideration, increased vagal tone (and thus vagal action) is associated with a diminished and more variable heart rate.

  3. Sympathetic nervous system - Wikipedia

    en.wikipedia.org/wiki/Sympathetic_nervous_system

    The sympathetic nervous system's primary process is to stimulate the body's fight or flight response. It is, however, constantly active at a basic level to maintain homeostasis. [4] The sympathetic nervous system is described as being antagonistic to the parasympathetic nervous system.

  4. Autonomic nervous system - Wikipedia

    en.wikipedia.org/wiki/Autonomic_nervous_system

    Autonomic nervous system, showing splanchnic nerves in middle, and the vagus nerve as "X" in blue. The heart and organs below in list to right are regarded as viscera. The autonomic nervous system has been classically divided into the sympathetic nervous system and parasympathetic nervous system only (i.e., exclusively motor).

  5. Body reactivity - Wikipedia

    en.wikipedia.org/wiki/Body_reactivity

    Startle response interrupts and disengages the organism from ongoing activity, directs attention to stimuli, and protects the organism from potential harmful stimuli. Orienting response is an organism's innate reaction to a novel stimulus, and it is a defensive response. [7] Heart rate increases after the onset of startle stimuli.

  6. Cardiac physiology - Wikipedia

    en.wikipedia.org/wiki/Cardiac_physiology

    As pressure and stretch decrease, the rate of baroreceptor firing decreases, and the cardiac centers increase sympathetic stimulation and decrease parasympathetic stimulation. [ 1 ] There is a similar reflex, called the atrial reflex or Bainbridge reflex , associated with varying rates of blood flow to the atria.

  7. Baroreflex - Wikipedia

    en.wikipedia.org/wiki/Baroreflex

    By coupling sympathetic inhibition and parasympathetic activation, the baroreflex maximizes blood pressure reduction. Sympathetic inhibition leads to a drop in peripheral resistance, while parasympathetic activation leads to a depressed heart rate (reflex bradycardia) and contractility. The combined effects will dramatically decrease blood ...

  8. Dysautonomia - Wikipedia

    en.wikipedia.org/wiki/Dysautonomia

    The autonomic nervous system is a component of the peripheral nervous system and comprises two branches: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PSNS). The SNS controls the more active responses, such as increasing heart rate and blood pressure. The PSNS slows down the heart rate and aids digestion, for example.

  9. Vagal tone - Wikipedia

    en.wikipedia.org/wiki/Vagal_tone

    In most cases, vagal tone is not measured directly. Instead the processes affected by the vagus nerve – specifically heart rate and heart rate variability – are measured and used as a surrogate for vagal tone. Increased vagal tone (and thus vagal action) is generally associated with a lower heart rate and increased heart rate variability.