1. What are the divisions of the PNS?

Somatic NS and Autonomic NS

2. What are the 2 divisions of the autonomic NS?

Sympathetic Division

Parasympathetic Division

3. Autonomic motor pathways consist of how many motor neurons in series? 2 See figure. How does this compare to the motor pathways in the somatic NS?

Autonomic motor pathways consist of 2 motor neurons in series. Motor pathways in the somatic ns only have one motor

4. Where are preganglionic cell bodies located? Are the axons myelnated or unmyelinated? What about postganglionic cell bodies and axons?

Preganglion neuron convey nerve impulses from CNS to autonomic ganglia (collection of neuronal cell bodies in PNS). Myelinated. In brain or spinal cord

Postganglionic neurons relay impulses from autonomic ganglia to visceral effectors (ex. Cardiac or smooth muscle). Unmyelinated. Outside CNS

5. Are pre and post-ganglionic neurons sensory or motor neurons?

motor

6. Are preganglionic neurons myelinated or unmyelinated? What about postganglionic neurons?

Preganglionic myelinated

Post ganglionic unmyelinated

7. There are 2 sites of synapses between sympathetic preganglionic and postganglionic neurons . What are these two types of ganglia? Where do they lie? Where do they innervate?

2 types of ganglia:

a. Sympathetic trunk ganglia-lie in vertical row on either side of vertebral column. Extend from base of skull to coccyx

i. Postganglionic axons innervate organs above diaphragm (head, neck, shoulders, and heart)

b. Prevertebral ganglia

i. Lie anterior to vertebral column and close to abdominal arteries

ii. Postganglionic axons innervate organs below diaphragm

8. In the sympathetic division, where are the cell bodies of the preganglionic neurons located within the spinal cord? What is another name for the sympathetic division?

Thoracolumbar (thoracic and lumbar)

Preganglionic neuron – inside CNS (lateral gray horns of Thoracic and Lumbar regions)

Postganglionic neuron – outside CNS (sympathetic trunk ganglia OR vertebral ganglia)

9. What are splanchnic nerves? Do they synapse in the sympathetic trunk? If not, then where?

Some sympathetic preganglionic axons pass through sympathetic trunk without terminating in it

Beyond the trunk, they form splanchnic nerves

Preganglionic axons that enter splanchnic nerves:

a. synapse with sympathetic postganglionic neurons in prevertebral ganglia that supply organs

10. Are the axons long or short in preganglionic and postganglionic neurons in the sympathetic NS?

Preganglionic axons short

Postganglionic axons long

11. In the parasympathetic division, where are the cell bodies of the preganglionic neurons located within the spinal cord? What is another name for the parasympathetic division?

a. preganglionic neurons are in 4 cranial nerves in the brain stem

Parasympathetic division known as: craniosacral division

12. Where do preganglionic axons of the parasympathetic division synapse with postganglionic neurons? Are these ganglia close to the spinal cord or target cells?

Preganglionic axons of parasympathetic division synapse with postganglionic neurons in terminal ganglia. close to the target cells

13. Are the axons long or short in preganglionic and postganglionic neurons in parasympathetic NS?

Postganglionic neurons are short

14. In the parasympathetic division, where are the cell bodies of the preganglionic neurons located within the spinal cord? What is another name for the sympathetic division?

craniosacral division. Lateral gray matter of sacral segments 2-4 of the spinal cord

15. What are autonomic plexuses?

autonomic plexuses (fibers that innervate visceral organs)

a. Plexus - network of inter-twining parts such as nerve fibers or blood vessels

16. What are the 2 major autonomic plexuses in the thorax? What organs does each supply?

Cardiac plexus-supplies heart

Pulmonary plexus-supplies lungs

17. What are cholinergic and adrenergic neurons? What do each release?

Cholinergic neurons- release acetyolcholine-

Adrenergic neurons- release norepinephrine (aka noradrenalin)

18. What are the 2 cholinergic receptors called? Where are each located?

Cholinergic neurons– release acetylcholine (Ach

1. nicotinic receptors (found in the ganglia)

2. Muscarinic receptors (found in the synapses with the effector organs)

19. Which NS division does cholinergic drugs mimic? What about adrenergic drugs?

Cholinergic drugs- Medications that produce the same effects as the parasympathetic NS

a. Purpose: inhibit, enhance, or mimic the action of the neurotransmitter acetylcholine

i. salivation, digestion, and muscle relaxation

Adrenergic drugs- Mimic or interfere with the functioning of the sympathetic nervous system

b. by affecting the release or action of norepinephrine and epinephrine

c. Purpose: act on your body to increase heart rate, sweating, and breathing rate, and decrease digestion

20. What is autonomic tone?

balance between sympathetic and parasympathetic activity

Pic on phone of the differences of sympathetic and parasympathetic divisions