Autonomic Nervous System Flashcards
(30 cards)
What is the autonomic nervous system (ANS)?
The ANS regulates involuntary bodily functions such as heart rate, digestion, and respiratory rate.
What are the two main divisions of the ANS?
The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS).
How does the sympathetic nervous system function? What is its role?
The SNS is a quick-response mobilizing system responsible for ‘fight or flight’ reactions.
How does the parasympathetic nervous system function? What is its role?
The PNS is a more slowly activated dampening system responsible for ‘rest and digest’ functions.
What does ‘tonically active’ mean in relation to the ANS?
The ANS is always active at a baseline level and adjusts activity to maintain homeostasis.
What role does the rostral ventrolateral medulla play in blood pressure regulation?
It contains premotor neurons that influence sympathetic activity to regulate blood pressure.
How do sympathetic and parasympathetic systems interact?
They often have antagonistic effects, but in some cases, they work synergistically.
What are the key functions of autonomic innervation of the heart?
Regulation of heart rate (chronotropism), contractility (inotropism), conduction velocity (dromotropism), and coronary blood flow.
What is the cardiac baroreceptor reflex?
A homeostatic mechanism that adjusts heart rate and vascular resistance to maintain blood pressure.
What are atropine and atenolol used for in ANS studies?
Atropine is a muscarinic acetylcholine receptor antagonist, and atenolol is a β-adrenergic receptor antagonist.
What happens in a vagotomy?
The vagus nerve is cut, reducing parasympathetic influence on target organs.
How does autonomic control differ between global activation and local regulation?
Global activation is rare; the ANS finely tunes responses based on organ-specific needs.
How does the ANS fit into the central nervous system (CNS)?
It relies on sensory and integrative input from the CNS to regulate bodily functions.
What are visceral reflexes?
Involuntary, unconscious reflexes that regulate internal organ functions, like heart rate and digestion.
Why is the ANS considered part of a network rather than autonomous?
It integrates with sensory and cognitive processes to ensure efficient regulation of body functions.
How is the autonomic nervous system (ANS) integrated into overall brain function?
The ANS is embedded in brain networks and interacts with sensory, emotional, and homeostatic processes.
What role does the ANS play in emotional responses?
The ANS mediates physiological changes in response to emotions, such as increased heart rate, pupil dilation, and altered respiration.
Which brain regions are involved in autonomic control of emotions?
Regions such as the hypothalamus, amygdala, and brainstem influence autonomic responses to emotional stimuli.
What physiological effects occur during fear responses?
Increased heart rate, increased respiration, dry mouth, tense muscles, sweaty palms, and pupil dilation.
How do positive emotions affect autonomic function?
Pleasant emotions can also cause strong autonomic reactions, sometimes leading to sudden cardiac events.
What is the significance of the 1994 Los Angeles earthquake in autonomic research?
It was associated with a spike in sudden cardiac deaths, demonstrating the link between stress and autonomic function.
How do cardiovascular events relate to emotional stress?
Studies show an increase in cardiac events during stressful events like World Cup soccer matches
How does heart rate variability (HRV) relate to health outcomes?
Reduced HRV is linked to increased cardiac mortality, as well as conditions like depression and schizophrenia.
What is baroreceptor sensitivity (BRS) and its relevance to health?
Decreased BRS is associated with a higher risk of cardiac mortality and poor autonomic regulation.
