Term
| What is the difference between preganglionic & postganglionic neurons? |
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Definition
pre = the neurons conducting signals to the ganglia
post = the ganglion cells & their axons |
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Term
| What neurotransmitter is used by preganglionic neurons (both sympathetic & parasympathetic)? |
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Definition
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Term
| What do visceral efferent neuron postganglionic fibers form around the organs they innervate? |
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Definition
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Term
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Definition
| small swellings on postganglionic fibers where they reach the vicinity of the effector cells & branch extensively; they form along the branches |
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Term
| Are the actions of the autonomic or somatic nervous system more diffusely distributed (both spatially & temporally)? |
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Definition
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Term
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Definition
| places where few nerve fibers supply a large number of smooth-muscle cells so that only a few cells are close to nerve varicosities |
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Term
| What kind of neurons do the autonomic ganglia contain? |
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Definition
| multipolar neurons of various sizes with long branching dendrites |
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Term
| Are there interneurons in the autonomic ganglia? |
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Definition
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Term
| Can autonomic ganglia serve as reflex centers for some visceral reflexes or are they just simple synaptic interruptions of purely motor pathways? |
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Definition
| they can serve as reflex centers for some visceral reflexes |
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Term
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Definition
| formed when an organ is innervated by both sympathetic & parasympathetic fibers that intermingle; exist just outside or in the wall of the organs |
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Term
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Definition
| on the outside of the heart; contains sympathetic & parasympathetic fibers & the cell bodies of the postganglionic parasympathetic neurons |
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Term
4 prevertebral plexuses
*hint: they get their names from the arteries they surround & follow peripherally* |
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Definition
1. celiac plexus
2. superior mesenteric plexus
3. inferior mesenteric plexus
4. renal plexus |
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Term
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Definition
| how the prevertebral plexuses continue into the pelvis |
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Term
| What is the difference between the location of sympathetic ganglia & parasympathetic ganglia? |
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Definition
sympathetic = close to the CNS
parasympathetic = close to the target organs |
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Term
| What is the difference between the neurotransmitter used for sympathetic postganglionic neurons & parasympathetic postganglionic neurons? |
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Definition
sympathetic = norepinephrine
parasympathetic = acetylcholine |
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Term
| Where do preganglionic sympathetic neurons have their cell bodies? |
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Definition
| the intermediolateral column in the spinal cord |
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Term
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Definition
| a continuous string made by the fiber bundles that interconnect the ganglia |
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Term
| 3 sympathetic ganglia in the cervical region of the spinal cord |
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Definition
1. superior cervical ganglia
2. middle cervical ganglia
3. inferior cervical ganglia |
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Term
| stellate ganglion (sympathetic) |
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Definition
| a large ganglion that is a fusion of the inferior cervical ganglion with the uppermost thoracic ganglion |
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Term
| white communicating ramus |
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Definition
| a small bundle in which the preganglionic sympathetic fibers leave the spinal nerve |
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Term
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Definition
| separate nerves formed when the preganglionic fibers pass directly through the ganglia & are destined for prevertebral sympathetic ganglia |
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Term
| Where do the head, neck, & upper extremity receive preganglionic sympathetic fibers from? |
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Definition
| the upper thoracic segments |
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Term
| Where does the head receive postganglionic sympathetic fibers from? |
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Definition
| the superior cervical ganglion |
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Term
| 2 nerves formed by the sympathetic fibers to the abdominal viscera |
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Definition
1. greater splanchnic nerve
2. lesser splanchnic nerve |
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Term
| celiac ganglion (sympathetic) |
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Definition
| the largest among the prevertebral ganglia; located where the celiac artery emerges from the aorta |
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Term
| Does the adrenal medulla receive sympathetic preganglionic fibers from the splanchnic nerves? |
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Definition
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Term
| What neurotransmitter do the chromaffin cells (the medullary endocrine cells which are transformed postganglionic cells) release into the bloodstream on sympathetic stimulation? |
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Definition
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Term
| Where do the visceral organs of the lower abdomen & the pelvis receive their sympathetic innervation? |
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Definition
| the intermediolateral column in the lower thoracic & upper two lumbar segments |
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Term
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Definition
| a meshwork of fibers that embed the prevertebral ganglia; named corresponding to those of the ganglia |
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Term
| Where do the preganglionic parasympathetic neurons have their cell bodies? |
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Definition
| in the brain stem & the sacral cord |
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Term
| 4 nerves followed by the preganglionic fibers of the cranial part of the parasympathetic system |
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Definition
1. oculomotor
2. facial
3. glossopharyngeal
4. vagus |
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Term
| 4 parasympathetic ganglia where the preganglionic fibers of the cranial nerves supplying the structures in the head end |
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Definition
1. ciliary
2. pterygopalatine
3. otic
4. submandibular |
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Term
| Do the parasympathetic preganglionic fibers of the vagus nerve end in well-defined ganglia or in more diffusely distributed collections of postganglionic neurons in the walls of the thoracic & abdominal organs? |
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Definition
| diffusely distributed collections of postganglionic neurons in the walls of the thoracic & abdominal organs |
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Term
| Do the sinus/atrioventricular nodes or the ventricles receive more parasympathetic postganglionic fibers? |
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Definition
| sinus & atrioventricular nodes |
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Term
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Definition
| the plexus around the trachea & bronchi that is innervated by the vagus & contains scattered postganglionic neurons |
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Term
| Where is the pelvis plexus (parasympathetic) located? |
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Definition
| immediately lateral to the rectum, the bladder, the prostate gland, & the cervix |
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Term
| Do postganglionic parasympathetic fibers innervate all the organs of the pelvis & the corpora cavernosa of the penis & the clitoris? |
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Definition
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Term
| Does the sacral parasympathetic division innervate the descending & sigmoid colon & the rectum? |
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Definition
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Term
| What is parasympathetic innervation of the rectum & the bladder responsible for? |
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Definition
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Term
| What is the difference in location between the myenteric plexus & the submucous plexus? |
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Definition
myenteric = between the circular & longitudinal external smooth-muscle layers
submucous = below the mucous membrane |
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Term
| 3 things monitored/controlled by the neurons of the enteric system |
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Definition
1. tension in the intestinal wall
2. chemical milieu of the mucosa
3. peristaltic movements of the bowel (moving content toward the anus) |
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Term
| What do excitatory neurons in the enteric system do? |
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Definition
| ensure constriction of the bowel above a bolus of intestinal contents |
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Term
| 2 neurotransmitters in excitatory neurons of the enteric system |
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Definition
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Term
| What do inhibitory neurons in the enteric system do? |
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Definition
| inhibit the circular muscle layer in front of a bolus, thus easing its propulsion |
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Term
| What is the main purpose of the parasympathetic system? |
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Definition
| control primarily processes that are necessary for the maintenance of the organism over a long term |
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Term
| What is the main purpose of the sympathetic system? |
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Definition
| mobilizing the resources of the body when an extra effort is required |
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Term
| Is the sympathetic system activated in an all-or-none fashion? |
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Definition
| no! some parts may be active while others are not |
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Term
| 3 jobs of sympathetic input to the circulatory system |
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Definition
1. cardiac output can be increased
2. maintain blood pressure
3. direct blood flow to the organs needing it the most |
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Term
| How does the sympathetic system increase the heart rate? |
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Definition
| acting on pacemaker cells in the sinus node |
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Term
| What increases with sympathetic innervation to the heart? |
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Definition
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Term
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Definition
| the smallest arteries which are especially concerned with the regulation of blood flow to the organs |
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Term
| 2 high-priority organs (sympathetic system ensures that there is a sufficient blood flow through them) |
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Definition
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Term
| What does the sympathetic system innervate to maintain adequate blood pressure? |
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Definition
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Term
| When does effective blood volume increase? |
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Definition
| constriction of the large veins that distributes more of the blood volume to the arterial side |
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Term
| What do sympathetic fiber signals to arterioles in skeletal muscles produce? |
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Definition
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Term
| What do sympathetic fibers produce in the vessels of the lungs? |
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Definition
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Term
| What does epinephrine do to bronchial musculature? |
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Definition
| it produces bronchial dilation |
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Term
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Definition
| the large arteries in the neck & the aortal arch that record the slightest fall in blood pressure & produce an automatic increase of the signal frequency of sympathetic fibers |
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Term
| What does sympathetic innervation of the skin do? |
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Definition
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Term
| What does sympathetic innervation to the sweat glands do? |
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Definition
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Term
| What neurotransmitter is released from postganglionic sympathetic fibers onto the sweat glands? |
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Definition
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Term
| 2 extreme situations when sweat secretion can occur |
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Definition
1. large drop in blood pressure
2. strong pain |
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Term
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Definition
| extreme situations when the skin vessels are maximally constricted & the skin is pale & cold |
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Term
| What does sympathetic innervation of the small smooth muscles attached to the hair roots on the skin do? |
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Definition
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Term
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Definition
| when the hairs on your skin stand up |
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Term
| What does sympathetic innervation to the abdominal viscera do? |
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Definition
| produces vasoconstriction & reduced contractile activity of the smooth muscles of the walls of hollow organs |
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Term
| What does sympathetic innervation to the rectum do? |
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Definition
| inhibits emptying of the rectum by inhibiting the smooth muscles of the wall & activating the smooth muscles of the internal anal sphincter |
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Term
| What does sympathetic innervation to the ductus deferens do? |
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Definition
| responsible for the rhythmic contractions during ejaculation |
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Term
| Where do sympathetic fibers to the eye have their cell bodies? |
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Definition
| superior cervical ganglion |
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Term
| 2 things sympathetic innervation does in the eye |
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Definition
1. dilation of the pupil by activating the pupillary dilator muscle
2. contraction of the radially oriented vessels of the iris |
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Term
| What type of secretion is produced by parasympathetic postganglionic fibers? |
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Definition
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Term
| What does parasympathetic innervation of the gastrointestinal tract/bladder do? |
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Definition
| increased strength & frequency of peristaltic contractions |
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Term
| What is the parasympathetic effect of the vagus nerve on airways? |
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Definition
| bronchial constriction & secretion |
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Term
| Do most of the vessels of the body receive parasympathetic innervation? |
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Definition
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Term
| What does parasympathetic innervation to the penis do? |
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Definition
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Term
| What does parasympathetic innervation of the oculomotor nerve of the eye do? |
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Definition
| reduces the diameter of the pupil & produces accommodation of the lens |
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Term
| What type of receptors does the released ACh bind to in the membrane of the postganglionic neurons in the autonomic ganglia? |
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Definition
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