Autonomic Nervous System

Question 1

Autonomic Nervous System

Answer 1

• Consist of motor neurons
• Also called involuntary nervous system

Question 2

Somatic vs. ANS

Answer 2

• Both:
  
  • ​have motor fibers
• Differ:
  
  • ​Origin
  • Effectors
  • Ganglia
  • Target organ responses to neurotransmitters

Question 3

Somatic NS (Origin)

Answer 3

• Origin:
  
  • cell body is in the ventral horn

Question 4

Somatic NS (effector)

Answer 4

• Effector:
  
  • ​Voluntary skeletal muscles

Question 5

ANS (Origin)

Answer 5

• Origin:​
  
  • Lateral horn

Question 6

ANS (effector)

Answer 6

• Effectors:
  
  • ​involuntary:
    
    • cardiac muscles
    • smooth muscles
    • glands

Question 7

Divisions of Autonomic Nervous System

Answer 7

1. Sympathetic (fight or flight)
   
   • Thoracolumbar Division
2. Parasympathetic (Rest and Digest)
   
   • Craniosacral Division

Question 8

Somatic NS uses a _____ motor neuron

Answer 8

Single

Question 9

All somatic motor neurons release _____

Answer 9

Acetylcholine (ACh)

Effects always stimulatory

Question 10

Autonomic nervous system uses ____ motor neuron chain

Answer 10

two

1. Preganglionic Neuron
2. Postganglionic Neuron

Question 11

Postganglionic fibers release _____ or _____ at effectors

Answer 11

• norepinephrine
• acetlycholine (ACh)
  
  • Effects are either stimulatory or inhibitory, depending on type of receptor

Question 12

Comparison (Picture)

Answer 12

Question 13

Localized vs. Widespread

Answer 13

1. Parasympathetic:
   
   • ​​short-lived, highly localized control over effectors (localized)
2. Sympathetic:
   
   • ​​longer lasting, bodywide effects (widespread)

Question 14

Role of the Parasympathetic NS

Answer 14

• Maintenance activities and conserves body energy
  
  • S.L.U.D.D
• Blood pressure, heart rate, resp. rate are low
• G.I Tract activity high
• Pupils constricted
• Immune system active
• Growth and repair (healing)

Question 15

SLUDD

Answer 15

• Salivation
• Lacrimation
• Urination
• Digestion
• Defecation

Question 16

Parasympathetic Nervous Systems does not affect ____ and ______ glands

Answer 16

adrenal and sweat glands

Question 17

Role of Sympathetic NS

Answer 17

• “fight or flight system”
• 4 e’s
  
  • increase heart rate and respiration
  • dry mouth
  • cold, sweaty skin; contract arrector pili muscles
  • dilated pupils
• Shunts blood to skeletal muscles and heart
• Liver release glucose

Question 18

4 e’s

Answer 18

1. Exercise
2. Excitement
3. Emergency
4. Embarrassment

Question 19

Which organs only receive sympathetic fibers?

Answer 19

1. Adrenal medulla
2. Sweat glands
3. Arrector Pili muscles
4. kidneys
5. most blood vessels

Question 20

Parasympathetic (Craniosacral) Division…

Answer 20

• Long preganglionic fibers from brain stem and sacrum
  
  • Extend from CNS almost to target organs
  • Synapse with postganglionic neurons in autonomic/terminal ganglia close to/within target organs
• Short postganglionic fibers synapse with effectors- hence effects are localized

Question 21

Sympathetic (Thoracolumbar) Division…

Answer 21

• Preganglionic neurons are in spinal cord segments T1-L2 in the lateral horns of spinal cord
• 23 sympathetic chain ganglia
• Short preganglionic neurons
• Long postganglionic neurons

Question 22

Preganglionic fibers pass through _______ and enter ______ _____ ______ (Sympathetic Division)

Answer 22

• Rami communicantes
• sympathetic trunk (chain) ganglia

Question 23

Preganglionic fibers pass directly to ______ _____ without synapsing

Answer 23

adrenal medulla

Question 24

Cranial Nerves of Parasympathetic division

Answer 24

• Oculomotor nerves III - smooth muscle of eye
• Facial Nerves VII - stimulate lacrimal glands in head
• Glossopharyngeal Nerves IX - parotid salivary glands
• Vagus Nerve X - neck and nerves plexuses for ~ all thoracic and abdominal viscera

Question 25

**\_\_\_\_\_\_\_\_ \_\_\_\_** release neurotransmitter ACh

Answer 25

**Cholinergic Fibers** * all ANS preganglionic axons * All Parasympathetic postganglionic axons at effector synapse

Question 26

**\_\_\_\_\_\_\_\_ \_\_\_\_** release neurotransmitter NE

Answer 26

**Adrenergic Fibers** * Most sympathetic postganglionic axons * Exception: sympathetic postganglionic fibers secrete ACh at **sweat glands**

Question 27

Most visceral organs have ____ \_\_\_\_\_\_\_

Answer 27

**Dual Innervation** (both para and sym. nerves) * Sym. Division increases heart and resp. rates, and inhibits digestion and elimination * Para. Division decreases heart and resp. rates, and allows for digestion and discarding of wastes

Question 28

\_\_\_\_\_\_\_ - main integrative center of ANS activity

Answer 28

**Hypothalamus** * other controls come from cerebral cortex, reticular formation, and spinal cord

Question 29

Centers of hypothalamus control include:

Answer 29

* Heart activity and blood pressure * Body temp, water balance, and endocrine activity * Emotional stages and biological drives * Reactions to fear and "fight or flight" system

Question 30

Homeostatic Imbalances of the ANS

Answer 30

* **Hypertension** * overactive sym. vasoconstrictor response to stress * treated with adrenergic receptor - blocking drugs

Question 31

Effects of Age on ANS

Answer 31

* Constipation * Dry Eyes * Frequent eye infections * Orthostatic hypotension * low blood pressure after position change * pressure receptors less responsive to blood pressure changes * cardiovascular center fails to maintain healthy blood pressure