Exercise Physiology: Neural Control of Circulation
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Questions and Answers

Who introduced the hypothesis of 'homeostasis'?

  • Robert Gros
  • Walter B. Cannon (correct)
  • Adrian et al.
  • J. Kevin Shoemaker

    • Blood pressure regulation is solely determined by cardiac output.

    False

    What is the role of the autonomic nervous system during exercise?

    It coordinates cardiovascular responses and modifies the cardiovascular system.

    The __________ integrates the motor, respiratory, and cardiovascular systems during physical exercise.

    <p>autonomic nervous system</p> Signup and view all the answers

    Match the following concepts with their descriptions:

    <p>Homeostasis = Sustaining physiological values within a narrow range Central command = Initiation of cardiovascular adjustments during exercise Neurovascular transduction = The conversion of neural signals into vascular responses Sympathetic nerve activity = Increases during stress and exercise</p> Signup and view all the answers

    Which of the following factors does NOT contribute to blood pressure regulation during exercise?

    <p>Respiratory rate</p> Signup and view all the answers

    The concepts discussed in the review are solely based on modern observations.

    <p>False</p> Signup and view all the answers

    What are circulating catecholamines, and who first defined them?

    <p>Circulating catecholamines are hormones that mediate cardiovascular responses, first defined by W.B. Cannon.</p> Signup and view all the answers

    What does the amplitude of synchronized cardiac sympathetic nerve activity reflect?

    <p>The number of activated pre- and post-ganglionic fibers</p> Signup and view all the answers

    The study by Nowak et al. focused on cerebral blood flow during voluntary handgrip.

    <p>True</p> Signup and view all the answers

    What physiological aspects were discussed by Krogh and Lindhard in their 1913 study?

    <p>Regulation of respiration and circulation during muscular work.</p> Signup and view all the answers

    The exercise blood pressure test of myocardial efficiency was described by ______ in 1918.

    <p>Lambert G</p> Signup and view all the answers

    Which of the following is NOT a focus of the studies referenced?

    <p>Intracranial pressure during exercise</p> Signup and view all the answers

    Match the researchers with their contributions:

    <p>Ninomiya et al. = Sympathetic nerve activity and heart Kluess et al. = Vasoconstriction in skeletal muscle Ogawa et al. = Functional brain mapping Langley = Muscle contraction and substances</p> Signup and view all the answers

    In what year did Krogh and Lindhard publish their findings?

    <p>1913</p> Signup and view all the answers

    What role does the insula cortex primarily play in cardiac function according to studies?

    <p>It can cause bradycardia or tachycardia depending on the region stimulated.</p> Signup and view all the answers

    The anterior insula activation is associated with bradycardia during exercise.

    <p>False</p> Signup and view all the answers

    Which sensory input may interfere with detecting cortical neural functional patterns?

    <p>Sensory input from the muscle.</p> Signup and view all the answers

    The medial prefrontal cortex is primarily activated when anterior insula stimulation leads to _____ during exercise.

    <p>tachycardia</p> Signup and view all the answers

    Match the brain regions with their associated effects during muscle activation:

    <p>Anterior insula = Tachycardia Posterior insula = Bradycardia Medial prefrontal cortex = Decreased activation during volitional exercise Inferior posterior insula = Associated with bradycardia</p> Signup and view all the answers

    What has been cautioned against regarding the insula's function?

    <p>It should be viewed as a homogenous region.</p> Signup and view all the answers

    Transcutaneous electrical stimulation of somatosensory afferents leads to decreased activation in the anterior insula.

    <p>True</p> Signup and view all the answers

    What electrical stimulation results are associated with muscle contractions and cardiac function?

    <p>Elevated activity of the anterior insula causes tachycardia, while posterior insula stimulation causes bradycardia.</p> Signup and view all the answers

    The studies encourage caution in interpreting the insula due to its _____ in function.

    <p>heterogeneity</p> Signup and view all the answers

    Match the type of neural patterns with their description:

    <p>Excitatory patterns = Increase in activity Inhibitory patterns = Decrease in activity Voluntary activation = Conscious control of muscles Involuntary activation = Automatic responses</p> Signup and view all the answers

    What phenomenon did Walter B. Cannon illustrate through his characterization of 'voodoo death'?

    <p>The effects of psychological stress on cardiovascular function</p> Signup and view all the answers

    Krogh and Lindhard first observed rapid respiratory responses in individuals during rest periods.

    <p>False</p> Signup and view all the answers

    What term was introduced in 1971 to describe the neural pattern that coordinates exercise and cardiovascular control?

    <p>central command</p> Signup and view all the answers

    Cerebral strokes often lead to fatalities due to catastrophic __________.

    <p>cardiac arrhythmias</p> Signup and view all the answers

    Match the following terms with their definitions:

    <p>Heart Rate (HR) = The number of beats per minute of the heart Blood Pressure (BP) = The force of blood against the walls of the arteries Postexercise Circulatory Occlusion (PECO) = A temporary cessation of blood flow after exercise Sympathetic Nervous System = Part of the autonomic nervous system that prepares the body for stressful situations</p> Signup and view all the answers

    Which brain area is associated with modulating cardiovascular function in individuals with cortical lesions?

    <p>Medial Prefrontal Cortex</p> Signup and view all the answers

    Neural factors were ruled out in Krogh and Lindhard's study regarding the rapid responses observed.

    <p>False</p> Signup and view all the answers

    In what year did Krogh and Lindhard conduct their observations?

    <p>1913</p> Signup and view all the answers

    Increased blood pressure can be influenced by __________ activation.

    <p>hyperadrenergic</p> Signup and view all the answers

    Which physiological change was noted by Krogh and Lindhard at the onset of heavy exercise?

    <p>Increased respiratory rate</p> Signup and view all the answers

    What physiological response is associated with the central command during voluntary standing up?

    <p>Suppression of pressor-evoked bradycardia</p> Signup and view all the answers

    Sympathetic modulation of blood flow and oxygen uptake is only relevant for exercising muscles.

    <p>False</p> Signup and view all the answers

    What reflex is reset by both central command and exercise pressor reflex?

    <p>Carotid sinus baroreflex</p> Signup and view all the answers

    The modulation of muscle sympathetic nerve activity during incremental leg cycling is studied in _______.

    <p>humans</p> Signup and view all the answers

    Match the following authors with their contributions:

    <p>Ichinose M = Study of central command and bradycardia Joyner MJ = Research on blood flow and O2 uptake Mitchell JH = Neural control of circulation during exercise Katayama K = Muscle sympathetic nerve activity during exercise</p> Signup and view all the answers

    The PreBotzinger complex neurons are involved in modulating heart rate and blood pressure.

    <p>True</p> Signup and view all the answers

    Which physiological response is explored by both Ishii K and Katayama K in their studies?

    <p>Muscle sympathetic nerve activity</p> Signup and view all the answers

    The _______ baroreflex is affected by both central command and exercise pressor reflex.

    <p>carotid sinus</p> Signup and view all the answers

    What was the primary focus of the research done by Joyner MJ et al. in 1992?

    <p>Blood flow and O2 uptake</p> Signup and view all the answers

    Study Notes

    A Century of Exercise Physiology: Key Concepts in Neural Control of Circulation

    • Cannon's Homeostasis Hypothesis: Walter B. Cannon introduced the concept of homeostasis—maintaining physiological values within a narrow range—essential for life even during stress. Physical exercise is a significant stressor requiring integration of motor, respiratory, and cardiovascular systems to match oxygen delivery with need at the cellular level. This includes thermoregulation, blood pressure regulation, and efficient energy provision.

    • Blood Pressure Regulation: Blood pressure control during exercise is a complex, controlled variable involving cardiac output and vascular resistance (conductance).

    • Autonomic Nervous System's Role: The autonomic nervous system plays a crucial coordinating role in blood pressure regulation during exercise.

    • Early 20th Century Discoveries: Several landmark studies between 1903 and 1932 significantly advanced our understanding of how the autonomic nervous system modifies cardiovascular function during exercise. These findings laid the groundwork for modern exercise physiology.

    • Central Command: Krogh and Lindhard (1913) proposed a central cerebral cortex neural mechanism, now known as "central command," coordinating cardiovascular and motor function.

    • Neurovascular Transduction: Adrian et al. (1932) directly recorded sympathetic activity. This work established a pathway to study brain signals influencing the circulation. Cannon (1933) defined circulating catecholamines (e.g., norepinephrine) as sympathetic neurotransmitters in relation to vascular responses (neurovascular transduction). This understanding is crucial in comprehending muscle blood flow regulation during exercise.

    • Exercise and Blood Pressure Changes: The relationship between exercise and blood pressure changes emerged in the 1880s. Early recordings (Gordon 1907) showed that prolonged submaximal exercise led to small blood pressure increases. However, blood pressure increases substantially more during the later stages of incremental whole body exercise (~50mmHg).

    • Importance of Volitional Effort: Elevated volitional effort influences heart rate responses to prolonged exercise. Peripheral sensors in fatigued muscles are essential for subsequent sympathetic responses - despite stopping the exercise or voluntary effort, the reflex continues.

    • Role of Central Command and Brain Regions: Accumulating evidence points to a crucial role for cerebral cortex sites in autonomic function, including the medial prefrontal cortex, insula cortex, amygdala, and hippocampus. The insula cortex, particularly its anterior portion, seems associated with rapid tachycardia and cardo-vascular control during exertion. The medial prefrontal cortex plays a role in modulating cardiovascular function. The impact of stroke involving the insula cortex on blood pressure and catastrophic arrhythmias is highlighted to illustrate the delicate balance between central control and autonomic functioning.

    • Neurovascular Transduction and Cardiovascular Rhythms: Sympathetic nerve activity to muscles exhibits rhythms linked to cardiac cycles, offering an insight into communication between the brain and end organs. Specific neurons in the ventrolateral medulla are involved. The variability in sympathetic nerve activity helps fine-tune responses related to end-organ function.

    • Multiple Sensory Inputs in Regulation: Multiple sources of sensory information—muscle metabolites, muscle tension, and baroreceptors—affect cardiovascular adjustments, with a complex interplay during exercise.

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    A Century of Exercise Physiology: Key Concepts in Neural Control of the Circulation PDF

    Description

    Explore key concepts in exercise physiology, focusing on neural control of circulation. This quiz covers the relationship between homeostasis, blood pressure regulation, and the autonomic nervous system's role during physical activity. Test your understanding and knowledge of historical advancements in the field from the early 20th century.

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