Introduction into the Autonomic Nervous System Flashcards
What is the autonomic nervous system?
the peripheral complex of nerves that control involuntary functions in the body
What are some things that the autonomic nervous system governs?
secretory glands, smooth muscle, cardiac muscle, and internal organs
What are the similarities between the somatic nervous system and the autonomic nervous system?
They both::
- Get signals from the periphery
- Get signals from higher brain levels
- Have integrative neurons in the CNS
In the somatic nervous system, efferents do what?
They go directly to the effector: neuron leaves the CNS and goes straight to the skeletal muscle that innervates it
In the autonomic nervous system, efferents do what?
They go to peripheral ganglia to synapse with other neurons that will go to the effector
What is a good way to remember when the sympathetic nervous system responds?
fight-or-flight
What is a good way to remember when the parasympathetic nervous system responds?
rest and digest
What is a synapse?
any connection via neurons or efferents where two cells are communicating
What is a ganglia?
a collection of synpases
Where do pre-ganglionic fibers of the sympathetic nervous system originate from?
cell bodies in the thoracic or lumbar regions of the spinal cord
What do the sympathetic pre-ganglionic fibers enter?
the paravertebral chain of sympathetic ganglia
Where is the paravertebral chain of sympathetic ganglia?
it is a chain of ganglia that run along the vertebral column and runs along the spinal cord
What is the size of the pre-ganglionic fibers of the sympathetic nervous system as compared to the post-ganglionic fibers?
the pre-ganglionic fibers are short, the post-ganglionic fibers are long
True or False: The sympathetic post-ganglionic fibers have singular innervation.
False: they often have multiple innervation
How does the sympathetic nervous system effect the heart?
General excitation: increased heart rate, contractile force, and conduction velocity
How does the sympathetic nervous system effect the GI system?
General inhibition:
Decreased digestion, motility, and secretion
Where do pre-ganglionic fibers of the parasympathetic nervous system originate from?
cell bodies in the midbrain, medulla, oblongata, or sacral region of the spinal cord
What do pre-ganglionic fibers of the parasympathetic nervous system enter?
ganglia close to (or within) innervated structures
What is the size of the pre-ganglionic fibers of the parasympathetic nervous system as compared to the post-ganglionic fibers?
the pre-ganglionic fibers are long, the post-ganglionic fibers are short
How does the parasympathetic nervous system effect the heart?
General inhibition: decreased heart rate, contractile force, and conduction velocity
How does the parasympathetic nervous system effect the GI system?
General excitation: increased digestion, motility, and secretion
What do the alpha 1 receptors of the sympathetic nervous system do in the blood vessels?
constriction
What do the beta 2 receptors of the sympathetic nervous system do in the blood vessels?
dilation
What does the parasympathetic system do in the blood vessels?
dilation, but constriction of the peripheral vasculature and other organs
Does skeletal muscle have more alpha 1 or beta 2 receptors?
beta 2
What does the sympathetic nervous system do the the bronchiolar smooth muscle?
relaxation via beta 2 receptors
What does the parasympathetic nervous system do to the bronchiolar smooth muscle?
contraction
Preganglionic fibers of teh sympathetic and parasympathetic nervous system are ______.
cholinergic
What is the general path of parasympathetic outflow?
Cholinergic preganglionic axon releases Ach onto a ganglion, then the cholinergic postganglionic axon releases Ach onto the effector cell
What is the general path of sympathetic outflow?
Cholineric preganglionici axon releases Ach onto the ganglion, then the adrenergic postganglionic axon releases epinephrine or norepinephrine onto the effector cell
What is the name (type) of the Ach receptor at the ganglion?
nicotinic receptor
What is the name (type) of the Ach receptor at the neuroeffector junction?
muscarinic receptor
What does fight-or-flight cause in the muscle?
breakdown of glycogen to produce glucose
What does fight-or-flight cause in the liver?
glycogenolysis (and gluconeogenesis)
What does fight or flight cause in the heart?
increase in heart rate and stroke volume increase
What does fight-or-flight cause in the lungs?
increase of respiratory rate, relaxation of bronchioles
What does fight-or-flight cause in the vasculature?
vasoconstriction in skin and viscera
What does fight-or-flight cause in the pupils?
dilation
What does fight-or-flight cause in the body hair?
erection
What does fight-or-flight cause in the sweat glands?
sweating
What are some catecholamines?
epinephrine and norepinephrine
What is the precursor to norepinephrine?
dopamine
What is the importance of acetylcholinesterase?
it is important to metabolize Ach
