the autonomic system

Question 1

divisions of the autonomic system

Answer 1

• parasympathetic (rest and digest) and sympathetic (fight or flight response)
  separate due to anatomical differences

Question 2

origin of the sympathetic nerves

Answer 2

-The thoracic and the lumbar of the spinal chord

Question 3

origin of the parasympathetic nerve

Answer 3

• the cranial/medullary and sacral of the spinal chord

Question 4

vagus nerve

Answer 4

-the tenth cranial nerve on the parasympathetic side connected to the heart, lungs and upper GI tract

Question 5

ganglion

Answer 5

-points of chemical communication

Question 6

pre-ganglion neurones

Answer 6

-myelinated
-all cholinergic (release acetylcholine and noradrenaline) results in the activation of post-ganglionic nicotinic ACh as their neurotransmitters (ligand-gated ion channels)

Question 7

post-ganglion neurones

Answer 7

-unmyelinated

Question 8

difference between sympathetic post-ganglion neurones are parasympathetic sympathetic

Answer 8

-parasympathetic post-ganglionic neurons are cholinergic. ACh acts on muscarinic ACh receptors(G protein-coupled).
-most sympathetic post-ganglion are noradrenergic (release noradrenaline) which acts on different adrenoreceptors.
-However, some are also cholinergic aswell

Question 9

sympathetic postganglionic neurons in the adrenal glands

Answer 9

-Sympathetic postganglionic neurons in the adrenal glands:* Are differentiated to form neurosecretory chromaffin cells
-chromaffin cells make and store adrenaline
-on sympathetic stimulation, these cells release adrenaline into the bloodstream

Question 10

drug interventions for cholinergic transmission

Answer 10

-Nicotinic acetylcholine receptors (nAChRs) at autonomic ganglia and at the somatic neuromuscular junction differ in structure. Therefore, some drugs have actions selective to autonomic ganglia (so-called ganglion-blocking drugs,
e.g. trimethaphan,
-The actions of endogenously released ACh can also be enhanced by cholinesterase inhibitors (e.g. pyridostigmine,

Question 11

side effects of drugs intervening in cholinergic transmission

Answer 11

• due to the lack of selectivity of the drugs e.g. non-selective Muscarinic ACh receptors agonist is likely to cause a decrease in heart rate, increase bronchoconstriction and increased sweating and salivation

Question 12

drugs causing anticholinergic side effects

Answer 12

• some, drugs designed for a different purpose possess some affinity for muscarinic acetylcholine receptors and acts as agonist
• exert both autonomic and CNS actions, in the eldery in particular
  cn result in blurred vision, dry mouth,hallucinations,seizures etc..