Autonomic Nervous System Flashcards
What is the autonomic nervous system?
A set of control mechanisms the body has. It is “self-governing”
What are the two divisions of the autonomic nervous system?
Sympathetic and parasympathetic
Give an example of an organ that has dual innervation and exhibits antagonistic control
The Heart
Give an example of when the sympathetic and parasympathetic system work together
Sexual function
parasympathetic - erection
sympathetic - ejaculation
Sweat glands and blood vessel smooth muscle are almost only innervated by __________ stimulation
Sympathetic
Sympathetic or parasympathetic stimulation: pupillary dilation?
Sympathetic
Sympathetic or parasympathetic stimulation: bronchodilation?
Sympathetic
Sympathetic or parasympathetic stimulation: vasoconstriction in skin and viscera?
Sympathetic
Sympathetic or parasympathetic stimulation: vasodilation in skeletal muscle and cardiac muscle?
Sympathetic
Sympathetic or parasympathetic stimulation: glycogenolysis is stimulated?
Sympathetic
Sympathetic or parasympathetic stimulation: pupillary constriction?
Parasympathetic
Sympathetic or parasympathetic stimulation: promotes secretion?
Parasympathetic
Sympathetic or parasympathetic stimulation: defecation and urination?
Parasympathetic
What are the most common types of receptors found in the sympathetic nervous system?
Adrenergic receptors
Are adrenergic receptors inhibitory or excitatory?
Can have either effect depending on type of receptor and signalling pathway
Give 2 examples of agonists of the adrenergic system
- Adrenaline
- Salbutamol
Which receptors are activated by adrenaline?
α and ß receptors
What are the effects of adrenaline binding to α and ß receptors?
- BP increases
- Dilates bronchi
What is adrenaline used for clinically?
Anaphylactic shock - epipen
What else could be used in place of adrenaline?
Cocaine and amphetamines
Which receptors does salbutamol bind to?
ß2
What is the clinical application of salbutamol?
Treat asthma as predominantly targets bronchiole smooth muscle
What is used as a ß1 antagonist in the adrenergic system?
ß1 - selective antagonists (ß-blockers)
What is the clinical application of ß2 antagonists in the adrenergic system?
No clinical use
What kind of receptors does acetylcholine bind to
Muscarinic receptors and nicotinic receptors
Give 2 examples of cholinergic agonists other than acetylcholine
- Muscarine
- Pilocarpine
Both bind to muscarinic receptors
What are the effects of muscarine?
- Decrease BP
- Increase saliva/tear flow/sweating
- Abdominal pain
- –> death from cardiac and respiratory failure
What is pilocarpine used for?
Eye drops, to treat glaucoma
Give 2 examples of cholinergic antagonists and which receptors they bind to
- Atropine: muscarinic
- Curare: nicotinic
What are the effects of atropine?
- Inhibition of secretion
- Smooth muscle relaxant
- Pupillary dilation
- Increase body temp.
Give examples of non-adrenergic, non- cholinergic “NANC” neurotransmitters
- Substance P
- Nitric oxide
- ATP
- VIP
What is nitric oxide produced by and where?
Produced by nitric oxide synthase in both sympathetic and parasympathetic neurones
What does nitric oxide activate?
cGMP
What does sildenafil do? What is it used for?
Pontentiates nitric oxide action. Used for erectile dysfunction
What is the effect of adrenaline binding to α1 receptors?
Stimulates phospholipase C
What is the effect of adrenaline binding to α2 receptors?
Inhibits adenylate cyclase
What kind of adrenergic receptors are found on adipocytes?
ß3
Where can ß3 adrenergic receptors be found?
On adipocytes
How come pilocarpine decreases heart rate?
Partial ACh agonist
