ANS intro Flashcards
What are the principal efferent outputs from the CNS
Autonomic
Somatic
Neuroendocrine
What are the principle target organs of the ANS
Eye Trachea and broncheoles Liver Adipose Kidney Ureters and bladder Salivary glands Skin Heart Gastrointestinal Blood vessels
What is the role of the sympathetic NS in the following organs: Eye Salivary glands Trachea and bronchioles Skin Liver
Dilation Thick and vicious secretion Dilation Piloerection and increased sweating Glycogenolysis and gluconeogenesis
What is the role of the sympathetic NS in the following organs: Heart Adipose Gastrointestinal Kidney Ureters and bladder Blood vessels
Increase rate and contractility
Lipolysis
Decrease motility and tone, sphincter contraction
Increased renin secretion
Relax dextrusor, contract trigone and sphincter
Dilate skeletal, constrict in skin/mucous membrane/splanchnic
What is the role of the parasympathetic NS in the following organs: Eye Salivary glands Trachea and bronchioles Heart Gastrointestinal Ureter and bladder
Constrict
Copious, watery secretion
Constrict
Decrease rate and contractility
Increase motility and tone and secretions
Contract dextrusor, relax trigone and sphincter
Describe neurotransmitter release from parasympathetic system
Long pre - short post
N ACh - M ACh
Describe the neurotransmitter release from the sympathetic nervous system
short pre - long post
N ACh - A NA
short pre - adrenal medulla - bloodstream
N ACh - NA/A
Short pre - long post
N ACh - M ACh
What is the ratio of pre to post in the PNS
1:1
What is the ratio of pre to post in the SNS
Up to 1:20
What is the neurotransmitter released from the somatic nervous system
ACh
Describe enteric nervous system action
Chemical substances in the gut lumen sensed by sensory neurones connected to mucosal chemoreceptors and stretch receptors
Information relayed to submucosal and myenteric plexus via interneurones
Motor neurones release ACh/substance P to contract SM or vasoactive intestinal peptide/NO to relax
Give features of nicotinic receptors
Found at all autonomic ganglia
Nicotine/ACh
Ionotropic type 1
Give features of muscarinic receptors
Found at all effector organs innervated by post ganglionic PNS fibres
Muscarine/ACh
G-protein coupled type 2
What are the subtypes of muscarinic cholinoreceptors
M1 - neural M2 - cardiac M3 - exocrine and smooth muscle M4 - periphery M5 - stratal dopamine release
Give features of adrenoceptors
At all effector organs innervated by post ganglionic sympathetic fibres
NA/A
G-protein coupled type 2
Describe the biosynthesis of acetylcholine
- Acetyl CoA + choline
Choline acetyl transferase - AcetylCholine + CoA
(into vesicle, exocytosis on Ca2+ influx due to AP)
acetylcholinesterase
3. Acetate + Choline
Describe the biosynthesis of noradrenaline
1. Tyrosine Tyrosine hydroxylase 2. DOPA DOPA decarboxylase 3. Dopamine Dopamine beta hydroxylase in the vesicle 4. Noradrenaline a. Uptake into the pre-synaptic bulb Monoamine oxidase A Metabolites b. Postsynaptic uptake+ peripheral uptake COMT
Describe the biosynthesis of adrenaline
1. Tyrosine Tyrosine hydroxylase 2. DOPA DOPA decarboxylase 2. Dopamine Dopamine hydroxylase 3. Noradrenaline PNMT 4. Adrenaline
What controls the ANS
Nucleus tractus solitarius
Where does the sympathetic nervous system eminate from
T1-L3
Which nerves make up the PNS
Sacral splanchnic S2-S4
Cranial III, VII, IX, X
What are the types of sympathetic adrenoreceptors
alpha 1 - A, B, D
alpha 2 - A, B, C
beta 1
beta 2
