The Autonomic Nervous System

Question 1

Somatic motor neuron?

Answer 1

*Somatic motor neuron: one motor neuron runs between spinal cord and skeletal muscle

Question 2

Visceral motor neurons?

Answer 2

*Visceral motor neurons: two motor neurons run between spinal cord and target tissue
- Preganglionic neuron
- Postganglionic neuron
- These 2 neurons synapse within an autonomic
ganglion

Question 3

General Functions of ANS

Answer 3

*Works in conjunction with visceral sensory division
*Self-governing and often involuntary motor
responses
- Innervates smooth muscle
– Digestion, blood pressure, urination
- Innervates cardiac muscle
- - Heart rate
- Innervates glands
- - Sweating, salivation, digestive enzymes

Question 4

What is ANS: Parasympathetic Division?

Answer 4

*Rest and digest
*Conserves energy and oversees standard bodily functions
*Localized effect: not much teamwork

Question 4

What is ANS: Parasympathetic Division?

Answer 4

*Rest and digest
*Conserves energy and oversees standard bodily functions
*Localized effect: not much teamwork

Question 5

What is ANS: Sympathetic Division

Answer 5

*Fight, fright, or flight
*Many organs involved
*Mobilizes body in extreme situations
- Fear
- Exercise
- Anger
*Short-term response, requires more energy

Question 6

Two divisions of ANS

Answer 6

These two divisions come from different parts of the CNS:
*Parasympathetic: exits from brainstem and sacral spinal nerves
*Sympathetic: exits from thoracic and lumbar regions

Question 7

Parasympathetic Pathway components

Answer 7

*Preganglionic axon: LONG
*Postganglionic axon: SHORT
*Autonomic ganglion is near or within target tissue

Question 8

Parasympathetic Neurotransmitters

Answer 8

*Synapse within autonomic ganglion: Acetylcholine
*Synapse between postganglionic axon and tissue: Acetylcholine

Question 9

What is the Vagus Nerve?

Answer 9

The vagus nerve (Cranial Nerve X) is an important part of the ANS
* It contains nearly 90% of the preganglionic parasympathetic fibers in the body
* Read: the vagus is important in bringing about the typical rest and digest activities in visceral muscle and glands

Question 10

What is Sympathetic Pathway?

Answer 10

*Preganglionic axon: SHORT
*Postganglionic axon: LONG
*Autonomic ganglion near spinal cord

Question 11

Sympathetic Neurotransmitters

Answer 11

*Synapse within autonomic ganglion: Acetylcholine
*Synapse between postganglionic axon and tissue: Norepinephrine

Question 12

What is Sympathetic Trunk ganglia?

Answer 12

*Sympathetic trunk ganglia
- Expansions of sympathetic trunk where pre- and postganglionic neurons synapse

Question 13

What is Sympathetic trunk?

Answer 13

*Sympathetic trunk
- Runs parallel to spinal cord
- Pathway for neurons of sympathetic division

Question 14

What is Adrenal Medulla and the Sympathetic NS?

Answer 14

*The adrenal (suprarenal) gland sits on top of both kidneys
*Internal adrenal medulla is a major organ of the sympathetic nervous system
- It is a specialized sympathetic ganglion
- Contains neuron-derived cells that release two excitatory hormones into blood during fight or flight response
* Norepinephrine (similar to epinephrine)
* Epinephrine (adrenaline)
- These hormones produce the widespread excitatory effects of fight or flight response
* BTW: Cortisol is one hormone released from adrenal cortex in response
to long-term stressors

Question 15

What is Adrenal Medulla and the Sympathetic NS?

Answer 15

*The adrenal (suprarenal) gland sits on top of both kidneys
*Internal adrenal medulla is a major organ of the sympathetic nervous system
- It is a specialized sympathetic ganglion
- Contains neuron-derived cells that release two excitatory hormones into blood during fight or flight response
* Norepinephrine (similar to epinephrine)
* Epinephrine (adrenaline)
* BTW: Cortisol is one hormone released from adrenal cortex in response to long-term stressors