Autonomic Nervous System Flashcards
What are the roles of the parasympathetic system?
Enhances energy storage; decreases cardiac output, blood pressure, increase gut peristalsis, salivation, pupillary constriction and bladder contraction.
What are the roles of the sympathetic nervous system?
Energy needs to be expended; increase heart rate, decreases peristalsis, blood from gut to muscles, adrenal gland can dump epinephrine into circulation so widespread, long-lasting effects possible.
What does the autonomic system control?
- Controls visceral activity
- You have no conscious awareness of heartbeat, breathing, digestion, sweat, diversion of blood to active muscles
What are the 3 main divisions of the autonomic system?
1) Sympathetic
2) Parasympathetic
3) Enteric nervous system
What are the similarities between the somatic and autonomic nervous systems?
Both have:
- Visceral sensory fibers
- Ascending pathways
- Descending pathways control motor neurons
- Reflexes
What is the one major difference between the somatic and autonomic systems?
- Sympathetic & parasympathetic efferents do not reach their targets directly: a two-neuron chain is involved
1) Preganglionic cell body in CNS, 2) postganglionic neuron in ganglion
Where are sympathetic ganglia located?
near CNS
Where are parasympathetic ganglia located?
near innervated organ
True or false: Sympathetic and parasympathetic preganglionic fibers have thin myelin.
True
True or false: Sympathetic and parasympathetic postganglionic fibers are myelinated.
False
Where is the neurotransmitter Ach (Acetylcholine) used?
In parasympathetic and in the 1st synapse in the sympathetic. Although they have different Ach receptors.
Where is the neurotransmitter NE (norepinephrine) used?
In the 2nd sympathetic synapse.
Where are the sympathetic preganglionic fibers?
from T1 to L2/3 segments
What is the path of the sympathetic preganglionic fibers?
travel in spinal nerve —> sympathetic change —> prevertebral ganglia —> adrenal gland
Where are parasympathetic preganglionic neurons located?
in the brainstem & sacral cord