ANS-CVS 1 Flashcards
where does sympathetic nerves arise?
emerge from thoracic area of spine
where does parasympathetic nerves arise?
from cranial nerves and lumbar sacral areas of spine
length of pre and postsynaptic nerve for sympathetic nerves
pre: short
post: long
ganglion: inside sympathetic chain
length of pre and postsynaptic nerve for parasympathetic nerves
pre: long
post: short
ganglion: in wall of organ/tissue
explain somatic nerve
- supply skeletal muscle
- no ganglions
main neurotransmitters in ANS?
Ach and NE
what organ/tissue in sympathetic pathway with no postsynaptic fibre?
adrenal gland
what sympathetic pathway that include both Ach and NE
pathway to smooth mucle, cardiac cells and gland cells to contract
functions of parasympathetic
- SLUDD (salivation, lacrimation, urination, digestion, defeacation)- anabolic, conserves and stores energy
functions of sympathetic
- fight or flight- catabolic, mobilises energy, raise BP and body temperature, dilates airways etc
non-adrenergic and non-cholinergic neurotransmitter
- nitric oxide- serotonin- ATP- GABA- dopamine- purines- neuropeptide
general sequence of neurotransmitter
- synthesis2. storage3. release4. recognition5. reuptake/metabolism
Ach synthesis by
choline acetyltranferase
hydrolysis of Ach by
acetylcholine esterase
choline reuptake by
Na+ driven symport
types of Ach receptors
- nicotinic (Nm and Nn)- muscarinic ( M1, M2, M3)
explain nicotinic receptors
- muscle-type and nerve-type2. cause membrane depolarization3. role in neuromuscular junction (skeletal) and ganglionic transmission (nerve)
explain muscarinic M1
- in CNS, ganglia, gastric, parietal cells2. increase IP3, DAG (excitation)3. role in memory CNS, gastric acid secretion, GI motility
explain muscarinic M2
- in cardiac conducting tissue and presynaptic terminals2. decrease CAMP (inhibition)3. role in cardiac, presynaptic and neural inhibition
explain muscarinic M3
- exocrine gland, smooth muscle and blood vessels2. increase IP3, DAG (excitation)3. role in secretion, SM contraction, vasodilatation
cholinoceptor agonists
- acetylcholine- carbachol- methacholine- bethanechol
cholinoceptor agonist that do not hydrolyse by AchE
bethanecol
Nicotinic muscular type agonist
- Ach- suxamethonium- decamethonium
nicotinic muscular type antagonist
- vecuronium- pancuronium
nicotinic nerve type agonist
- Ach- nicotine- epibatidine
nicotinic nerve type antagonist
- trimetaphan- hexamethonium
AchE can be block by
serine occlusion
products of hydrolysis of AchE are
- choline- acetic acid- regenerated enzyme
reuptake of NA is blocked by
- cocaine- tricyclic antidepressants
adrenoceptor B1
- in heart, intestine, smooth muscle2. increase cAMP3. increase BP
adrenoceptor B2
- In bronchial, vascular and uterine smooth muscle2. bronchodilation, vasodilation, uterine SM3. increase cAMP
adrenoceptor A1
- postsynaptic 2. increase IP3, DAG3. increase BP4. cause vasoconstriction
adrenoceptor A2
- presynaptic2. decrease cAMP
a adrenoreceptors agonist specificity
noradrenaline > adrenaline > isoprenaline
b adrenoreceptors agonist specificity
isoprenaline >> adrenaline > noradrenaline
a adrenoreceptors antagonist specificity
phentolamine
b adrenoreceptors antagonist specificity
propanalol
actions of NA terminated by when
- reuptake into nerve terminal2. dilution and diffusion from cleft and uptake at non-neuronal sites3. metabolic transformation
enzymes important in biotransformation of cathecholamines
- COMT (cathecol-0-methyl transferase)2. MAO (monoamine oxidase)
