Neuro - Sympathetic and Parasympathetic Divisions

Question 1

Identify the location of the preganglionic and postganglionic nerve cell bodies in the sympathetic division of the ANS. What are the neurotransmitters in each for the sympathetic division?

Answer 1

• preganglionic neuron cell body - lateral horn of T1-L2 with acetylcholine as its neurotransmitter
• postganglionic neuron cell body - sympathetic ganglia with norephinephrine as its neurotransmitter

Question 2

What are the courses of the preganglionic and postganglionic neurons in the ANS?

Answer 2

• preganglionic neuron - cell body of origin located in CNS and terminates in the ganglion
• postganglionic neuron - terminates in the target tissue

Question 3

Identify the location of the preganglionic and postganglionic nerve cell bodies in the parasympathetic division of the ANS. What are the neurotransmitters in each for the parasympathetic division?

Answer 3

• preganglionic neuron cell body - brainstem autonomic nuclei and the saccral cord with acetylcholine as its neurotransmitter
• postganglionic neuron cell body - parasympathetic ganglia in the wall of viscera with acetylcholine as its neurotransmitter

Question 4

List the cranial and spinal nerves that carry sympathetic fibers.

Answer 4

lateral horn of spinal cord levels T1-L2 (thoracolumbar)

Question 5

List the cranial and spinal nerves that carry parasympathetic fibers.

Answer 5

CN III (occulomotor), VII (facial), IX (glossopharyngeal), X (vagus), and lateral horn of sacral cord S2-S4 (craniosacral)

Question 6

Identify the levels of the neuraxis that contain preganglionic sympathetic nerve cell bodies.

Answer 6

T1-L2

Question 7

Identify the intermediolateral cell column (lateral horn).

Answer 7

place of the sympathetic preganglionic nerve cell body

Question 8

By what route do sympathetic fibers reach the cranium (and cranial nerves)? Are these pre- or postganglionic fibers?

Answer 8

preganglionic nerve cell bodies in T1-L2 have axons that go to the paravertebral (chain) ganglion, prevertebral (collateral) ganglion, and adrenal medulla; postganglionic nerve fibers then reach the head via cervical ganglia and the carotid plexus

Question 9

What effect does sympathetic activation have on pupil diameter?

Answer 9

dilates pupils

Question 10

What effect does sympathetic activation have on blood vessel diameter?

Answer 10

constricts blood vessels

Question 11

What effect does sympathetic activation have on salivation?

Answer 11

increase salivation

Question 12

What effect does sympathetic activation have on the bronchi?

Answer 12

dilates the bronchioles

Question 13

What effect does sympathetic activation have on the heart rate?

Answer 13

increases rate and force of contraction

Question 14

Describe Horner syndrome and list/describe the resulting conditions.

Answer 14

• a loss of sympathetic innervation to the face
• symptoms:
  
  • ptosis - eyelid droop (superior tarsal muscle)
  • miosis - small pupil
  • endophthalmos - apparent sunken eye
  • anhydrosis - dry skin
  • heterochromia - eyes are each a different color (if Horner syndrome before 2 years of age)

Question 15

Describe the enteric nervous system (purpose, plexuses, etc.).

Answer 15

• provides innervation for intestinal tract, pancreas, and gall bladder
• neural plexus between layers of muscle and endothelium in the intestinal tract
  
  • myenteric plaxus (of Auerbach)
  • submucous plexus (of Meissner)
• provides primary control of motility and secretion

Question 16

Identify the levels of the neuraxis that contain preganglionic parasympathetic nerve cell bodies.

Answer 16

brainstem autonomic nuclei (midbrain, pons, and medulla) and sacral cord (S2-S4)

Question 17

By what route do parasympathetic fibers reach the thorax and abdomen? Are these pre- or postganglionic fibers?

Answer 17

• vagus preganglionic nerve cell bodies in dorsal motor nucleus and nucleus ambiguous have axons that travel with other vagus nerve fibers that terminate in the wall of the target tissue (which is the location of the postganglionic nerve cell bodies)
• sacral preganglionic nerve cell bodies in the lateral horn of S2-S4 exit within the ventral root and course within splanchnic nerves and terminate in the wall of target tissue (which is the location of the postganglionic nerve cell bodies)

Question 18

What effect does parasympathetic activation have on pupil diameter?

Answer 18

pupil consticts

Question 19

What effect does parasympathetic activation have on salivation?

Answer 19

salivation increases

Question 20

What effect does parasympathetic activation have on heart rate?

Answer 20

decreases rate and force of contraction

Question 21

What is effect produced by the parasympathetic fibers of CN III (occulomotor)?

Answer 21

• pupilary constictor muscle fibers decrease pupil diameter (pupilary reflex)
• ciliary muscle accommodates lens for near vision

Question 22

What is effect produced by the parasympathetic fibers of CN VII (facial)?

Answer 22

• nasal and lacrimal glands produce lacrimation

- submandibular and sublingual salivary glands produce a thin, watery mucous

Question 23

What is effect produced by the parasympathetic fibers of CN IX (glossopharyngeal)?

Answer 23

parotid salivary gland produces a thin, watery mucous

Question 24

What is effect produced by the parasympathetic fibers of CN X (vagus)?

Answer 24

• reduces heart rate and blood pressure

- increases gastric secretion and peristaltic activity

Question 25

What is effect produced by the parasympathetic fibers of the sacral cord S2-S4?

Answer 25

increases intestinal secretion and peristaltic activity

Question 26

List the sympathetic pathway of the pupillary reflex.

Answer 26

lateral horn -> paravertebral chain ganglion -> superior cervical ganglion -> carotid plexus -> eye (?)

Question 27

List the sympathetic pathway for salivation.

Answer 27

lateral horn -> paravertebral chain ganglion -> superior cervical ganglion -> carotid plexus -> glands (?)

Question 28

List the sympathetic pathway to the bronchi.

Answer 28

lateral horn -> paravertebral chain ganglion -> inferior (stellate) cervical ganglion -> brachial plexus