Autonomic Nervous System Review

Question 1

Divisions

Answer 1

sympathetic:
AKA thoracolumbar
Fight or flight

parasympathetic :
AKA craniosacral
Rest and Digest

Question 2

Describe the sympathetic division of the ANS

Answer 2

Originates in the posterior nuclei in the hypothalamus

Preganglionic fibers arise from the intermediolateral horn from T1 to L2

Question 3

Describe the sympathetic plexuses and their levels

Answer 3

Cardiac plexuses - T1-T4
Greater Splanchnic - T5-9
Lesser splanchnic  T10 - 11
Least splanchnic T12
Inferior hypogastric - L1 and L2

Question 4

What is the main end organ neurotransmitter in the sympathetic system and the neurotransmitter in the sympathetic ganglia

Answer 4

Organs: noreinephrine EXCEPT for sweat glands which is acetylcholine

Ganglia: acetylcholine (nicotinic)

Question 5

Describe the parasympathetic division of the ANS

Answer 5

Originates in the nuclei in the anterior hypothalamus
Carried by 4 CN: III, VII, IX, & X and 3 sacral nerves S2,3,4
Gangila are closer to end organs
Long preganglionic fibers and short postganglionic
ACH is the transmitter in BOTH the ganglia and end organs

Question 6

Describe the Parasympathetic g. in the head (4)

Answer 6

Ciliary CN III: located in the orbit attached to the nasociliary branch of CN V1, distributed to the sphincter pupillae and ciliary musle

pterygopalatine CN VII: located in the pterygopalatine fossa attached to the trunk of CN V2, distributed to the lacrimal, nasal, and palatine glands

Submandibular CN VII: located on the hypoglossal muscle and attached to lingual branch of CN V3, distributed to the submandibular and sublingual salivary glands

Otic CN IX: Location - foramen ovale, attached to CN V3, distributed to the parotid g,

Question 7

Describe the types of neurotransmitters

Answer 7

Two types in ANS:

Cholinergic - ACH:
All ACH receptors are nicotonic (EXCEPT postganglionic receptors and the sweat gland receptors which are muscarinic) Including the ACH receptor in the nueromuscular junction

Adrenergic - norepinephrine

Question 8

Name the tissues that don’t have both sympathetic and parasympathetic innervation (BABAS)

Answer 8

Bronchial g (only parasympathetic) 
      Rest are sympathetic 
Arrector pili  
Blood vessels
Adrenal medulla
Sweat glands

Question 9

Describe adrenergic receptors

Answer 9

Two types:

alpha - cause contraction of smooth muscle (dilator pupillae and arrector pili),

Beta - all are b2 (cause relaxation of smooth muscle) EXCEPT those found in the heart which are b1 (cause in increase in HR and force contraction) and those found in fat cells which are b3

Question 10

Describe the enteric brain

Answer 10

Myenteric plexus of Auerbach:
found between the inner circular and outer longitudinal smooth muscle layers of the muscularis externa and regulates motility of these muscles

Submucosal plexus of Meissner:
lies under the mucosa and regulates the secretion of intestinal glands

Question 11

Describe the viscerovisceral reflex

Answer 11

Begins and ends with viscera

Reflex is mediated by CN IX (afferent) and the sympathetic fibers to the heart (efferent)

for example: pressure in the carotid sinus in the neck results in a reflex which slows the HR and causes a drop in BP

Question 12

Describe the viscerosomatic reflex

Answer 12

Originates in a internal organ and causes a pheripheral muscle to contract or relax

for example the hering-breur rreflex in which inflation of the lungs triggers the diaphragm to relax is mediated by the vegus and phrenic nerves

Question 13

Describe the somatovisceral reflex

Answer 13

starts in segmental paraspinal muscles and ends in viscera

Example: paraspinal muscle spasms triggered by internal disc disruption causing spinal nerve root irritation which results in visceral dysfunction
This is mediated through preganglionic fibers in the sympathetic trunk