Autonomic Nervous System and Cholinergic Pharmacology Flashcards Preview

MSI Module II > Autonomic Nervous System and Cholinergic Pharmacology > Flashcards

Flashcards in Autonomic Nervous System and Cholinergic Pharmacology Deck (25):
1

Effector tissues of somatic versus autonomic motor systems

Somatic

  • Skeletal muscle

Autonomic

  • Cardiac muscle
  • Smooth muscle
  • Exocrine glands

2

Location of pre and post-ganglionic neurons in sympathetic division of ANS

Pre-ganglionic neurons

  • Lateral horn (interomediolateral column) of spinal cord segments T1 - L2/L3

Post-ganglionic neurons

  • Paravertebral sympathetic ganglia found in association with ventral rami of spinal nerves
  • Prevertebral (preaortic) sympathetic ganglia found on anterior surface of abdominal aorta

3

Location of pre and post-ganglionic neurons in parasympathetic division of ANS

Pre-ganglionic neurons (craniosacral nerves)

  • Brainstem
  • Interomediolateral column of S2-S4 segments of spinal cord

Post-ganglionic neurons

  • Most are located in terminal ganglia embedded in walls of abdominopelvic and thoracic vertebrae

4

Neurotransmitters released by pre-ganglionic sympathetic neurons and receptors at effector site

Acetylcholine released

N2-type nicotinic receptors at post-ganglionic neuron

5

Neurotransmitters released by post-ganglionic sympathetic neurons and receptors at effector site

Both norepinephrine and acetylcholine released

Receptors for NE

  • Alpha 1, alpha 2, beta 1, beta 2
  • ***At smooth muscle and glands

Receptors for Ach

  • M receptors
  • *** only at sweat glands

6

Neurotransmitters released by pre-ganglionic parasympathetic neurons and receptors at effector site

Acetylcholine

N2 Ach receptor on post-ganglionic neuron

7

Neurotransmitters released by post-ganglionic parasympathetic neurons and receptors at effector site

Acetylcholine

M receptor on effector organ

8

Chromaffin cells

Cells in the adrenal medulla that are homologous to post-ganglionic sympathetic neurons

  • Reside near blood vessels and when stimulated, release NE and E into blood 
    • More E than NE
    • Derived from same lineage of neural creast cells as sympathetic neurons

 

9

Effects of sympathetic and parasympathetic innervation on SA node of heart

Sympathetic

  • Beta 1 receptor
  • Increase heart rate

Parasympathetic

  • M2 receptor
  • Decrease heart rate

10

Effects of sympathetic and parasympathetic innervation on bronchioles

Sympathetic

  • Beta 2 receptor
  • Dialates

Parasympathetic

  • M3 receptor
  • Constricts

11

Effects of sympathetic and parasympathetic innervation on smooth muscle in GI tract

Sympathetic

  • Alpha 2 and Beta 2 receptors
  • Relaxation

Parasympathetic

  • M3 receptor
  • Contraction

12

Effects of sympathetic and parasympathetic innervation on smooth muscle in walls of urinary bladder

Sympathetic

  • Beta 2 receptor
  • Relaxation

Parasympathetic

  • M3 receptor
  • Contraction

13

Effects of sympathetic and parasympathetic innervation on salivary secretion

Sympathetic

  • Beta 1 receptor
  • Increase

Parasympathetic

  • M3 receptor
  • Increase

14

Effects of sympathetic and parasympathetic innervation on sphinctors of GI tract

Sympathetic

  • Contracts

Parasympathetic

  • Relaxes

15

Effects of sympathetic and parasympathetic innervation on sphincters of urinary bladder

Sympathetic

  • Contracts

Parasympathetic

  • Relaxes

16

Effects of sympathetic and parasympathetic innervation on radial (dilator pupillae) of the eye

Sympathetic

  • Alpha 1 receptor
  • Dilates pupil

Parasympathetic

  • N/A

17

Effects of sympathetic and parasympathetic innervation on sphincter (contstrictor pupillae) of the eye

Sympathetic

  • N/A

Parasympathetic

  • M3 receptor
  • Constricts pupil

18

Effects of sympathetic and parasympathetic innervation on sweat glands

Sympathetic

  • M3 receptor
  • Increases

Parasympathetic

  • N/A

19

Effects of sympathetic and parasympathetic innervation on lacrimal glands

Sympathetic

  • N/A

Parasympathetic

  • M3 receptor
  • Secretion

20

Effects of sympathetic and parasympathetic innervation on liver

Sympathetic

  • Alpha 2 and beta 2 receptors
  • Gluconeogenesis and glycogenolysis

Parasympathetic

  • N/A

21

Nicotonic acetylcholine receptor mechanism of action

Ligand gated ion channel

  • Open nonspecific cation channel leading to depolarization

22

Muscarinic acetylcholine receptor mechanism of action

M1, M3, M5

  • Increase production of PIP3​ which increases intracellular Ca+2
  • Gαq signaling

M2 & M4

  • Decrease adenylyl cyclase activity which ultimatly decreases cAMP levels
  • Gαi​ signaling

23

Classes of muscarinic receptor agonists

Choline esters ("chol")

  • Acetylcholine, methacholine, carbachol 
    • All work on muscarinic and nicotinic receptors
  • Bethanechol 
    • Acts exclusivley on muscarinic receptors

Cholinomimetic alkaloids (both act exclusivley on muscarinic receptors)

  • Muscarine (not used therapeutically)
  • Pilocarpine

24

Commonly used muscarinic receptor antagonists

  • Atropine
    • "Classic" and blocks all sub-types
  • Scolpolamine
    • Naturally occuring
  • Pirenzepine
    • Synthetic

25

Q image thumb

Capitate