lecture 26

Question 1

o Identify where the cell body of each neuron is located

Answer 1

 Cell body of the pre is in the CNS, moves from the CNS out to the ganglion
 Cell body of the post is in the ganglion, moves from the ganglion out to the effector organ

Question 2

o Identify what neurotransmitter(s) is/are released by each neuron

Answer 2

 Acetylcholine -> pre
 Acetylcholine or norepinephrine -> post

Question 3

o Preganglionic and postganglionic neuron lengths

Answer 3

 Preganglionic – before the ganglion, send the signal from the paraganglion to the ganglion
* Has an axon with light myelination
 Postganglionic – is an autonomic ganglion, and travels away from the ganglion then out to the effector organ
* Is nonmyelinated, has no myelin sheath

Question 4

o Neurotransmitters used

Answer 4

 The preganglionic neuron uses acetylcholine
 The postganglionic neuron uses either acetylcholine or norepinephrine

Question 5

 Sympathetic: fight or flight mode

Answer 5

• Prepares the body for action
  o Dilates pupils, decreases salvation, increases breathing rate, increases heart rate, narrows blood vessels, slows digestive activity, stimulates release of epi and norepi, causes salt and water retention, relaxes bladder muscles, inhibits defecation
• Has a short preganglionic fiber, then a ganglion, and then a long postganglionic fiber that goes to the effector
• The preganglionic neuron secretes acetylcholine, the postganglionic neuron secreted norepinephrine

Question 6

 Parasympathetic: rest and digest mode

Answer 6

• Conserves energy
  o Constricts pupils, increases salvation decreases breathing rate, slows heart rate, widens blood vessels, increases digestive activity, contracts the bladder muscles, stimulates defecation
• Has a long preganglionic fiber, then the ganglion, and then a short post ganglionic fiber that goes to the effector

Question 7

o Describe where each division originates (i.e. thoracolumbar vs. craniosacral origins)

Answer 7

 Thoracolumbar – spinal nerves T1-L2 (sympathetic)
* Preganglionic sympathetic cell bodies are found in the lateral horns of the spinal cord
 Craniosacral – Brain and S2-S4 (parasympathetic)

Question 8

lateral horn

Answer 8

o Lateral horns of the spinal cord
 Where the preganglionic sympathetic cell bodies are found

Question 9

sympathetic trunk

Answer 9

 Are chains of ganglia (looks like beads) that run along both sides of the vertebral column. It allows signals to travel up or down the trunk like structure, or even out to the effectors
 The sympathetic action comes from all the trunk and spine

Question 10

white ramus communicans

Answer 10

o Sympathetic trunk
 Are chains of ganglia (looks like beads) that run along both sides of the vertebral column. It allows signals to travel up or down the trunk like structure, or even out to the effectors
 The sympathetic action comes from all the trunk and spine

Question 11

gray ramus commincans

Answer 11

 Is where the postganglionic sympathetic fibers travel through to exit the sympathetic trunk
* Is not myelinated

Question 12

• Identify the cranial nerves that carry parasympathetic nerve fibers

Answer 12

o Oculomotor – pupil constriction, ciliary muscles
o Facial – nasal, lacrimal, and salivary glands
o Glossopharyngeal – parotid salivary glands
o Vagus – most thoracic and abdominal organs

Question 13

o Identify which organs are innervated by only sympathetic fibers

Answer 13

 Sweat glands – allows perspiration
 Arrector pili muscles – allows hair to stand on ends
 Adrenal medulla – gives us adrenaline rushes
 Most blood vessels – will help with constriction and dilation or vessels

Question 14

describe the components of the visceral reflex arc

Answer 14

o The receptor in the viscera receives and responds to the stimulus
o Then the signal is sent along the visceral sensory neuron to be sent to the integration center
o The integration center takes the signal and integrates the signal to decide what to do with it
 Could be a dorsal horn interneuron
 Could be within the walls of the GI tract
 May be a preganglionic neuron
o Will then send the integrated signal to the motor neuron which will carry it out to the visceral effector
o Visceral effector – what receives the integrated signal