Sistema nervoso autônomo simpático e parassimpático - Brasil Escola

Summary

In this educational video, Professor Fred explains the autonomic nervous system, which is divided into the sympathetic and parasympathetic systems. He discusses how these systems regulate involuntary functions in the body, such as heart rate, digestion, and pupil dilation. The sympathetic system prepares the body for action, releasing adrenaline to increase heart rate and reduce saliva production, while the parasympathetic system promotes relaxation, lowering heart rate and aiding digestion. Through clear examples and explanations, Professor Fred illustrates the antagonistic relationship between these two systems, emphasizing their role in maintaining the body's homeostasis.

Takeaways

• 😀 The autonomic nervous system (ANS) is part of the peripheral nervous system and controls involuntary actions.
• 😀 The ANS is divided into two branches: sympathetic and parasympathetic, which work antagonistically.
• 😀 The sympathetic nervous system prepares the body for action, often referred to as the 'fight or flight' response.
• 😀 Noradrenaline is the primary neurotransmitter in the sympathetic system, triggering bodily responses like increased heart rate and pupil dilation.
• 😀 The parasympathetic nervous system promotes relaxation and recovery, often called the 'rest and digest' system.
• 😀 Acetylcholine is the primary neurotransmitter in the parasympathetic system, helping slow heart rate and increase digestion.
• 😀 The sympathetic system increases heart rate, dilates pupils, and inhibits saliva production to prepare the body for stress or danger.
• 😀 The parasympathetic system counteracts the sympathetic system by decreasing heart rate and supporting digestive processes.
• 😀 The ANS is crucial for maintaining homeostasis, ensuring that bodily functions are neither excessive nor insufficient.
• 😀 Both sympathetic and parasympathetic systems impact similar organs, but their effects are opposite, depending on the situation (e.g., rest vs. stress).

Q & A

What are the two main divisions of the autonomic nervous system?

The autonomic nervous system is divided into two main parts: the sympathetic and parasympathetic systems.

How does the autonomic nervous system function in relation to the central nervous system?

The autonomic nervous system operates by transmitting nerve impulses from the central nervous system (CNS) to target organs or muscles, mainly controlling involuntary functions.

What is the role of the autonomic nervous system in maintaining homeostasis?

The autonomic nervous system plays a crucial role in maintaining homeostasis by regulating vital functions such as heart rate, saliva production, and pupil constriction to ensure the body operates in a balanced state.

What neurotransmitter is primarily associated with the sympathetic nervous system?

The sympathetic nervous system primarily releases norepinephrine (noradrenaline) as its neurotransmitter.

How does the sympathetic nervous system prepare the body for action?

The sympathetic nervous system triggers the release of adrenaline, preparing the body for fight-or-flight responses by increasing heart rate, dilating pupils, and redirecting blood flow to muscles.

What is the main function of the parasympathetic nervous system?

The parasympathetic nervous system is responsible for promoting relaxation, conserving energy, and supporting functions like digestion by decreasing heart rate and facilitating bodily repair processes.

What neurotransmitter does the parasympathetic nervous system use?

The parasympathetic nervous system uses acetylcholine as its primary neurotransmitter, which promotes muscle relaxation and slows down bodily functions like heart rate.

How do the sympathetic and parasympathetic systems work in opposition to each other?

The sympathetic and parasympathetic systems are antagonistic; for example, while the sympathetic system increases heart rate and prepares the body for action, the parasympathetic system decreases heart rate and supports relaxation.

What happens to the body during activation of the sympathetic nervous system?

During activation of the sympathetic nervous system, the body undergoes a series of changes such as increased heart rate, pupil dilation, reduced saliva production, and heightened muscle readiness, all aimed at preparing the body for immediate physical exertion.

What is the relationship between the autonomic nervous system and the visceral organs?

The autonomic nervous system innervates the visceral organs, such as the heart, digestive organs, and glands, regulating their functions involuntarily to maintain internal balance and respond to environmental changes.