Anatomic Nervous System Flashcards
Functions of parasympathetic nervous system (20 cards)
Define parasympathetic tone and its significance in organ function.
Parasympathetic tone refers to the state where organs are always slightly activated by the parasympathetic division, maintaining a baseline level of function.
How does the sympathetic division interact with the parasympathetic division during stress?
The sympathetic division can override the effects of the parasympathetic division during times of stress.
What effect do drugs that block parasympathetic responses have on heart rate and urinary function?
These drugs increase heart rate and cause fecal and urinary retention.
Identify the neurotransmitters released by postganglionic fibers in the sympathetic nervous system.
Most postganglionic fibers release norepinephrine (adrenergic), while postganglionic fibers serving sweat glands release acetylcholine (ACh).
Identify the two types of cholinergic receptors in the autonomic nervous system.
The two types of cholinergic receptors are nicotinic receptors and muscarinic receptors.
Explain the origin of the parasympathetic nervous system.
The parasympathetic nervous system originates from the craniosacral part, specifically from brain stem nuclei of cranial nerves and spinal cord segments.
Describe the location of ganglia in the parasympathetic division.
Ganglia in the parasympathetic division are located within the visceral organ (intramural) or close to the organ they serve.
Explain how the parasympathetic division affects heart rate and digestive activity.
It slows the heart rate and dictates normal activity levels of the digestive and urinary tracts.
Describe the primary function of the parasympathetic division of the autonomic nervous system (ANS).
The parasympathetic division normally dominates heart and smooth muscle of digestive and urinary tract organs, activating most glands except for adrenal and sweat glands.
How do the lengths of preganglionic and postganglionic fibers differ in the parasympathetic division?
The parasympathetic division has long preganglionic fibers and short postganglionic fibers.
What is the communication pattern of the parasympathetic division with rami?
The parasympathetic division has no communication with rami.
Describe the degree of branching of preganglionic fibers in the parasympathetic division.
The parasympathetic division has a minimal degree of branching of preganglionic fibers.
What are adrenergic receptors and their role in the autonomic nervous system?
Adrenergic receptors are metabotropic receptors that bind to norepinephrine and epinephrine, playing a key role in the sympathetic division of the autonomic nervous system
Describe the main function of the parasympathetic nervous system.
The main function is maintenance, conserving and storing energy, often referred to as ‘rest and digest’.
Explain the type of fibers released by all preganglionic and postganglionic fibers in the parasympathetic nervous system.
All preganglionic and postganglionic fibers release acetylcholine (ACh), making them cholinergic fibers.
Define the origin of the sympathetic nervous system.
The sympathetic nervous system originates from the thoracolumbar part, specifically the lateral horns of the gray matter of spinal cord segments.
How are the ganglia of the sympathetic nervous system positioned relative to the central nervous system (CNS)?
The ganglia are located within a few centimeters of the CNS, alongside the vertebral column (sympathetic trunk) and anterior to the vertebral column (collateral, prevertebral ganglia).
Describe the characteristics of the fibers in the sympathetic nervous system.
The sympathetic nervous system has short preganglionic fibers and long postganglionic fibers.
Explain the communication pathways in the sympathetic nervous system.
The sympathetic nervous system communicates through gray and white rami communicants, where white rami may contain myelinated preganglionic fibers and gray rami contain non-myelinated postganglionic fibers.
What is the functional role of the extensive branching of preganglionic fibers in the sympathetic nervous system?
The extensive branching of preganglionic fibers prepares the body for fight or flight activity.
