Podcast
Questions and Answers
What is primarily released by most postganglionic sympathetic (SNS) neurons onto their target cells?
What is primarily released by most postganglionic sympathetic (SNS) neurons onto their target cells?
What structure forms a unique type of synapse at the neuroeffector junction?
What structure forms a unique type of synapse at the neuroeffector junction?
What is the primary role of the autonomic division of the peripheral nervous system?
What is the primary role of the autonomic division of the peripheral nervous system?
Which neurotransmitter is secreted directly into the blood by the adrenal medulla?
Which neurotransmitter is secreted directly into the blood by the adrenal medulla?
Signup and view all the answers
How do the sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS) primarily differ in their effects?
How do the sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS) primarily differ in their effects?
Signup and view all the answers
Which branch of the autonomic nervous system primarily controls cardiac muscle?
Which branch of the autonomic nervous system primarily controls cardiac muscle?
Signup and view all the answers
What neurotransmitter do most postganglionic PSNS neurons release?
What neurotransmitter do most postganglionic PSNS neurons release?
Signup and view all the answers
Which statement accurately describes the anatomical differences between the SNS and PSNS?
Which statement accurately describes the anatomical differences between the SNS and PSNS?
Signup and view all the answers
What differentiates the SNS from the PSNS in terms of neurotransmitter release at target tissues?
What differentiates the SNS from the PSNS in terms of neurotransmitter release at target tissues?
Signup and view all the answers
What is the role of receptor subtypes in autonomic neurotransmitter function?
What is the role of receptor subtypes in autonomic neurotransmitter function?
Signup and view all the answers
How do autonomic reflexes contribute to homeostasis in the body?
How do autonomic reflexes contribute to homeostasis in the body?
Signup and view all the answers
Which component is not a characteristic of all autonomic pathways?
Which component is not a characteristic of all autonomic pathways?
Signup and view all the answers
What is the sequence of neurons in an autonomic pathway?
What is the sequence of neurons in an autonomic pathway?
Signup and view all the answers
What best describes the adrenal medulla?
What best describes the adrenal medulla?
Signup and view all the answers
Which of the following statements about the neurotransmitter release in SNS and PSNS is incorrect?
Which of the following statements about the neurotransmitter release in SNS and PSNS is incorrect?
Signup and view all the answers
What physiological functions are monitored by the autonomic control centers?
What physiological functions are monitored by the autonomic control centers?
Signup and view all the answers
Study Notes
Peripheral Nervous System - Efferent Division
- The efferent division carries information from the central nervous system (CNS) to target tissues through efferent neurons
- The peripheral nervous system's efferent division has two main subdivisions: autonomic and somatic motor neurons
- The autonomic division controls internal organs, glands, some adipose tissue, and smooth and cardiac muscle
- The somatic motor neurons control skeletal muscles
Objectives
- Describe the physiological function of the autonomic division (and its branches)
- Compare and contrast the anatomy and communication methods of the sympathetic (SNS) and parasympathetic (PSNS) branches
- Describe how autonomic neurotransmitters are synthesized and broken down
- Describe the structure and secretions of the adrenal medulla
SNS vs PSNS
- The sympathetic nervous system (SNS) is dominant during stressful situations ("fight or flight")
- The parasympathetic nervous system (PSNS) is dominant during calm activities ("rest and digest")
- These two branches work together to maintain homeostasis (a dynamic balance)
Autonomic Reflexes
- The hypothalamus, pons, and medulla initiate autonomic, endocrine, and behavioral responses
- The goal is to maintain homeostasis
- Information from sensory neurons goes to control centers in the hypothalamus, pons, and medulla
- This triggers autonomic, endocrine, and behavioral responses
Autonomic Control Centers
- These centers monitor and regulate involuntary body functions (e.g., blood pressure, body temperature, respiration, water balance)
- Key centers include the hypothalamus, pons, and medulla
Autonomic Pathways
- Autonomic pathways involve a series of two neurons
- These are preganglionic and postganglionic neurons that synapse in an autonomic ganglion and at a target tissue
SNS and PSNS Differences
- Differences occur in origin in the CNS, autonomic ganglion location, and length of ganglionic axons.
SNS and PSNS Responses
- These systems often affect the same organs but frequently work in opposition to each other.
- The table provides specific examples of responses of each system in different organs (eye, salivary glands, heart, lungs, digestive tract, pancreas, adrenal medulla, kidney, etc).
SNS and PSNS Neurotransmitters and Receptors
- Preganglionic neurons (both SNS and PSNS) release acetylcholine (ACh) onto postganglionic nicotinic receptors.
- Most postganglionic PSNS neurons release ACh onto muscarinic receptors.
- Most postganglionic SNS neurons release norepinephrine (NE) onto adrenergic receptors.
Neuroeffector Junction at the Target Tissue
- Autonomic varicosities release neurotransmitter over the surface of target cells
- Target cells have receptors specific for the neurotransmitter
Neurotransmitter Release and Removal at a Neuroeffector Junction
- Neurotransmitter release involves exocytosis of synaptic vesicles following an action potential
- Neurotransmitters are removed by diffusion, re-uptake, or enzymatic breakdown
- The table provides details on the characteristics of different receptors and how they are affected by neurotransmitters (e.g., types of receptors, neurotransmitter specificity, second messenger effects).
Adrenal Medulla
- The adrenal medulla is a modified sympathetic ganglion
- The chromaffin cells secrete the neurohormone epinephrine directly into the blood.
Comparison of Sympathetic and Parasympathetic Branches
- This table details the points of origin, locations, and neurotransmitters for each branch of both systems
- This is a review of the differences.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the efferent division of the peripheral nervous system, focusing on its subdivisions: autonomic and somatic motor neurons. This quiz will help you understand their physiological functions, compare the sympathetic and parasympathetic branches, and learn about autonomic neurotransmitters and the adrenal medulla.
