Autonomic Nervous System Flashcards
(36 cards)
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
How do parasympathetic nerves travel?
in cranial & sacral nerves
Where does the parasympathetic system outflow to?
thoracic, abdominal and pelvic viscera, none to limbs
What are the components in cranial parasympathetics?
- III, pupil sphincter and ciliary muscle, accomodation reflex
- VII, pterygopalatine ganglion
- IX, otic ganglion
- X, to heart, lungs, lower esophagus, stomach, ascending and transverse colon, pancreas
What are key points on the path of CN III Oculomotor?
- Edinger-Westphal nucleus, located in midbrain
- Ciliary ganglion
- It controls pupillary constrictor muscle fibers, which decrease pupil diameter (pupillary reflex)
- It controls the ciliary muscle, which accommodates lens for near vision
What are key points on the path of CN VII Facial?
- Superior salivatory nucleus in tegmentum of pons, made up of parasympathetic preganglionic cell bodies
- Axons exit along with other facial nerve fibers, they terminate in 1) the pterygopalatine ganglion and lacrimal gland; and 2) the submandibular ganglion and sublingual salivary glands
What are key points in the path of CN XI Glossopharyngeal?
- Inferior salivatory nucleus in the medulla, parasympathetic preganglionic cell bodies of glossopharyngeal nerve are there.
- Axons exit along with other glossopharyngeal nerve fibers and terminate in the otic ganglion and parotid salivary gland
What are key points in the path of CN X Vagus?
- Dorsal motor nucleus has Parasympathetic preganglionic cell bodies serving GI tract and gut derivatives, and Nucleus ambiguus which has Parasympathetic preganglionic cell bodies serving heart. Both of these are in medulla.
- Axons exit along with other vagal nerve fibers, they terminate in the wall of target tissue (viscera from thorax to transverse colon)
What are key points in the path of Sacral Parasympathetic Outflow?
- Sacral cord, S2-4 level, region of lateral horn, location of preganglionic parasympathetic cell bodies
- Axons exit within ventral root and course within splanchnic nerves
- They terminate in wall of target tissue (Viscera from transverse colon to rectum
Includes bladder, uterus, etc.)
Location of postganglionic nerve cell bodies
Select the correct matching pair. A) Superior salivatory nucleus: IX B) Edinger-Westphal: IV C) Nucleus ambiguus: X D) Inferior salivatory nucleus: VI E) Selena Gomez: Justin Bieber
C) Nucleus ambiguus: X
