Questions and Answers
What is the primary role of the parasympathetic division of the autonomic nervous system?
What is the primary function of baroreceptors in relation to blood pressure?
How does the autonomic nervous system respond to a fall in blood pressure?
Which system primarily controls dynamic antagonism in organ function?
Signup and view all the answers
What can modify the activities of the autonomic nervous system?
Signup and view all the answers
Which organs receive only sympathetic innervation?
Signup and view all the answers
What main function is associated with the sympathetic system?
Signup and view all the answers
Which of the following statements about dual innervation is true?
Signup and view all the answers
Which type of signaling involves hormones released into the bloodstream?
Signup and view all the answers
What would likely occur if the parasympathetic system discharged as a complete entity?
Signup and view all the answers
Which of the following is NOT considered a local mediator?
Signup and view all the answers
What effect does vagal parasympathetic innervation have on the heart rate?
Signup and view all the answers
What is the characteristic of dynamic antagonism in organ control?
Signup and view all the answers
What physiological changes result from sympathetic innervation when blood pressure drops?
Signup and view all the answers
What is the primary role of efferent neurons in the autonomic nervous system?
Signup and view all the answers
Which of the following does NOT typically result from sympathetic stimulation?
Signup and view all the answers
Which response is triggered during emergencies by the sympathetic nervous system?
Signup and view all the answers
What is one of the primary functions of the parasympathetic nervous system?
Signup and view all the answers
Which of the following statements about enteric neurons is true?
Signup and view all the answers
What happens to blood flow during sympathetic activation?
Signup and view all the answers
What triggers the release of epinephrine during a sympathetic response?
Signup and view all the answers
What are the effects of sympathetic division stimulation?
Signup and view all the answers
What is the role of norepinephrine in the sympathetic nervous system?
Signup and view all the answers
Which of the following systems is recognized as a second messenger system?
Signup and view all the answers
Which protein is involved in the activation of adenylyl cyclase?
Signup and view all the answers
What is one of the products released by phospholipase C in the calcium/phosphatidylinositol system?
Signup and view all the answers
What occurs after a neurotransmitter binds to a receptor?
Signup and view all the answers
Which of the following describes a second messenger?
Signup and view all the answers
Activation of which protein subunit leads to the amplification of signals in the phosphatidylinositol system?
Signup and view all the answers
What does diacylglycerol act as in intracellular signaling?
Signup and view all the answers
What initiates the release of neurotransmitters at the nerve ending?
Signup and view all the answers
Which neurotransmitter is commonly associated with cholinergic transmission?
Signup and view all the answers
What characterizes adrenergic fibers?
Signup and view all the answers
Which of the following neurotransmitters is considered inhibitory?
Signup and view all the answers
What is the role of increased intracellular Ca2+ in neurotransmitter release?
Signup and view all the answers
During sympathetic system responses, which neurotransmitter is typically involved?
Signup and view all the answers
In relation to neurotransmitter classification, what does cholinergic specifically refer to?
Signup and view all the answers
Which neurotransmitter is involved in mediating the transmission at the autonomic ganglia?
Signup and view all the answers
Study Notes
Autonomic Nervous System (ANS) Overview
- Efferent neurons transmit signals from the brain to initiate actions in the peripheral nervous system.
- Afferent neurons sense environmental changes, conveying information from sensory receptors (e.g., visual, auditory).
- Enteric neurons, often referred to as the "brain of the gut," function independently of the CNS, regulating gastrointestinal activity.
Sympathetic Division Effects
- Stimulation leads to increased heart rate and blood pressure, mobilizing energy and enhancing blood flow to skeletal muscles and the heart.
- Results in dilation of pupils and bronchioles, impacting gastrointestinal motility and urinary and sexual organ functions.
- Functions as part of the fight or flight response, activated during emergencies, involving both direct sympathetic stimulation and adrenal medulla epinephrine release.
Parasympathetic Nervous System Functions
- Primarily responsible for maintaining homeostasis and essential functions (e.g., digestion, waste elimination).
- Generally counteracts sympathetic actions, dominating in "rest and digest" states.
- Acts independently without full system discharge to prevent adverse effects, such as involuntary urination.
Reflex Responses
- Baroreceptors detect blood pressure drops, reducing signals sent to cardiovascular centers.
- Triggers increased sympathetic output and decreased parasympathetic activity, resulting in elevated blood pressure and heart rate.
Emotions and the ANS
- Strong emotional stimuli (rage, fear, pleasure) can influence autonomic nervous system activity.
Dual Innervation in Organs
- Most organs receive innervation from both sympathetic and parasympathetic divisions.
- For instance, vagal innervation slows heart rate, while sympathetic innervation increases it, allowing dynamic balance for homeostatic control.
Organs with Sympathetic Only Innervation
- Certain organs, including the adrenal medulla, kidneys, pilomotor muscles, and sweat glands, are innervated solely by the sympathetic system.
- Blood pressure control is predominantly managed through sympathetic activities.
Chemical Signaling Mechanisms
- Hormones are secreted by endocrine cells into the bloodstream; local mediators act locally (e.g., histamine).
- Neurotransmitters enable communication between nerve cells and effector organs, with release mechanisms involving Ca2+ influx.
Types of Neurotransmitters
- Acetylcholine: Mediates transmission for cholinergic neurons at autonomic ganglia, influencing both sympathetic and parasympathetic systems.
- Norepinephrine and Epinephrine: Characterize adrenergic fibers in the sympathetic system, mediating communication from autonomic postganglionic neurons to effector organs.
Second Messenger Systems
- Second-messenger molecules, generated upon neurotransmitter-receptor binding, amplify cellular responses.
- Common pathways include the adenylyl cyclase system and the calcium/phosphatidylinositol system, involving proteins like Gs and Gq for signal transduction.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers key concepts from Lecture 3 on the autonomic nervous system, focusing on drugs that affect its function. It explores the roles of efferent and afferent neurons and their significance in pharmacology. Test your understanding of how various drugs interact with the ANS.
