autonomic nervous system

Question 1

describe properties of neurons in the sympathetic nervous system

Answer 1

Preganglionic neurons

• Short
• Myelinated
• Ach

Postganglionic neurons

• Long
• Light myelin
• 90% NA 10% Ach

Question 2

describe properties of neurons in the parasympathetic nervous system

Answer 2

Preganglionic neurons

• Long
• Ach
• Light myelin

Postganglionic neurons

• Short
• Near targets
• Can be in loose plexi - embedded in the target organs
• Ach

Question 3

draw diagram of sympathetic outflow from the spinal corrd

Answer 3

preganglionic axons has 3 different routes

Question 4

what are the actions of the sympathetic nervous system?

Answer 4

Question 5

what are the actions of the paraympathetic nervous system?

Answer 5

mostly associated with cranials nerve III VII IX X

Question 6

what are the neurotransmitters in sympathetic nervous system

Answer 6

Preganglionic neurons

• Ach

Post ganglionic neurons

• 90% NA
• 10% Ach
• • neuropeptides
    
    • Somatostatin
    • Substance P

Question 7

what are the neurotransmitters in parasympathetic nervous system

Answer 7

Preganglionic neurons

• Ach

Post ganglionic neurons

• Ach
• • neuropeptides
    
    • VIP
    • CGRP
• • NO

Question 8

what is different about neuropeptides?

Answer 8

only change the effects of Ach and NA

therefore NOT neurotransmitters

are NEUROMODULATORS

Question 9

what are the types of adrenergic receptor types

how are they different?

Answer 9

• a₁, a,₂ B₁, B2, B₃

_​

• different tagets express different receptor types
• Adrenaline and noradrenaline effects depend on adrenergic receptor types
• GCPR = slow acting & prolonged

Question 10

describe a₁

Answer 10

an adrenergic receptor type

• coupled to G_q
• activation of phospholipase C
• contaction of smooth muscle in blood vessels
• promotes kidney Na⁺ reabsorption

Question 11

describe a₂

Answer 11

type of adrenergic receptor

• coupled to Gi
• inhibits adenylate cyclase - reduces cAMP
• contraction of blood vessel smooth muscle
• reduced lipolysis in adipose tissue

Question 12

describe B₁

Answer 12

type of adrenergic receptor

• coupled to G_s
• activates adenylate cyclase - increases cAMP
• increases heart rate & contraction strength
• increased lipolysis in adipose tissue

Question 13

describe B₂

Answer 13

type of adrenergic receptor

• coupled to G_s
• activates adenylate cyclase - increases cAMP
• relaxation of smooth muscle in blood vessels, gut, uterus + bronchi
• increased glycogen breakdown in liver

Question 14

increases B₃

Answer 14

type of adrenergic receptor

• coupled to G_s
• activates adenylate cyclase - increases cAMP
• relaxation of smooth muscles in bladder
• modulates intestinal mobility

Question 15

describe types of acetylcholine receptors

Answer 15

Question 16

what is the enteric nervous system?

Answer 16

in the lining of the gut

• regulates gut motility
• regulates secretion of mucous and digestive enzymes

Question 17

what is the structure of the enteric nervous system

Answer 17

Coordinated contraction of longitudinal and circular muscle -> peristalsis

Auerbach’s plexus inbetween muscle layers

Meissner’s plexus in submucosa

Question 18

what neurons are there in the enteric nervous system

Answer 18

Sensory

• Auerbach’s plexus
  
  • Measure strach in smooth muscle
• Meissners
  
  • Measure chemical composition of lumen

Motor

• Visceromotor neurons
  
  • Inhibitory and excitatory work together to peristalasisss
• Secretomotor neurons
  
  • Promote mucous release into lumen

Interneurons

• Connect
  
  • Creates circuit

Question 19

what regulatory input to enteric nervous system ?

Answer 19

Only has regulatory input from vagus nerve and prevertevral ganugligon neurons

ENS can function independent of brain

Question 20

describe the pupillary reflex

draw and label

Answer 20

1. Shining light

• activates retinal ganglion neurons
• project to nucleus ipsilateral pretectal nucleus
  
  • Same side of brain
• Retinal ganglion neurons are melanopsin containing photosensitive retinal ganglion cells

2. Bilateral innervation of Edinger-wesphal nucleus which contains preganglionic parasympathetic neurons
3. These preganglionic parasympathetic neurons project axons along cranial nerve III
   * synapses with postganglionic parasympathetic neurons in the ciliary ganglion
4. Axons from the postganglionic parasympathetic neurons project to radial sphincter
5. Induce contraction of sphincter

Question 21

how is autonomic nervous system regulated?

Answer 21

Visceral sensory neurons - sensory feedback

• • visceral sensory DRG neurons
• • visceral sensory neurons of the petrosal ganglion
    
    • (associated with cranial nerve IX)
• • visceral sensory neurons of the nodose ganglion
    
    • (associated with cranial nerve X)

Question 22

how is visceral sensory information sent to solitary tract in medulla?

Answer 22

• Visceral sensory (afferent) neurons associated with cranial nerves IX (petrosal ganglion neurons) and X (nodose ganglion neurons) directly innervate the nucleus of the solitary tract (NST) in the medulla
• Drg ganglions indirectly innervate NST through second order visceral afferents
  
  • projection interneuron goes into NST – DRG does not

Question 23

what is the solitary tract divided into?

Answer 23

solitary tract nucleus in 2 divisions :

• Visceral sensory division
• Taste division

Question 24

missed one thing at end of lecture need to go through