ANS L2: ANS Neurotransmitter and receptors Flashcards
For the adrenal gland, once stimulated ACh releases ___ and _____.
NE and E
Generally - most blood vessels ______ (vasoconstriction/vasodilation) (excitatory repsonse) but some dilate (ones going to the muscles being highly use- receptors inhibitory response –> relax
vasoconstriction
IMPORTANT DIAGRAM
Nicotinic and muscarinic receptors are _______ receptors
cholinergic
What are receptors for the sympathetic preganglion?
ACH
What are receptors for the parasympathetic preganglion?
ACH
What are receptors for the sympathetic autonomic ganglion?
Nicotinic
What are receptors for the parasympathetic autonomic ganglion?
Nicotinic
What are receptors for the sympathetic postganglion?
Adrenaline Noradrenaline
What are receptors for the parasympathetic postganglion?
ACH
What are receptors for the sympathetic effector cells?
α1, α2, β1, β2 receptors α1, α2, β1, β2 receptors are adrenergic receptors Many subtypes and all have different effects and affinities
What are receptors for the parasympathetic effector cells?
Muscarinic
IMPORTANT SLIDE
Where is the site of the nicotinic receptor?
All autonomic ganglia
- Motor end plate of skeletal muscle fibres
- Some CNS cell bodies and dendrites
Where is the site of the muscarinic receptor?
Effector cells (cardiac muscle, smooth muscle, glands)
- Some CNS cell bodies and dendrites
What is the response to Ach release from the nicotinic receptor?
- Sympathetic and parasympathetic preganglionic fibres Motor neurons
- Some CNS presynaptic terminals
What is the response to Ach release from the muscarinic receptor?
Parasympathetic postganglionic fibres
- Some CNS presynaptic terminals
What are the 4 adrenergic receptors?
α1, α2, β1, β2
What are the 4 characteristics of α1 receptors?
- < Adrenaline > Noradrenaline
- (If put equal amounts ore likely to bind more to noradrenaline )
- Ca 2+ second messenger system
- Excitatory response, contraction of smooth muscle
- Arterioles, most sympathetic target tissues
What are the 5 characteristics of α2 receptors?
- < Adrenaline & > Noradrenaline
- Higher affinity for NE
- Blocks cyclic AMP production
- Inhibitory response, relaxation of smooth muscle
- Digestive tract
- If increases NE –> Git starts to slow down its activity
What are the 4 characteristics of β1 receptors?
- ~ Adrenaline & ~ Noradrenaline
- Cyclic AMP secondmessenger system
- Excitatory response
- Heart (kidney, liver)
What are the 4 characteristics of β2 receptors?
- Mostly Adrenaline
- Higher affinity for E
- Cyclic AMP secondmessenger system
- Inhibitory response, relaxation of smooth muscle
- Bronchioles, arterioles
You are a drug designer and being asked to develop a drug that reduces heart rate in the treatment of hypertension. Based on todays’ information you would develop a drug that…
EXAM QUESTION
selectively blocks β1 adrenergic receptors thereby reducing the sympathetic effects on the heart. Such drugs (Metoprolol, Atenolol) are called β1 antagonists.
Drug –> beta 1 antagonist (beta blockers)
Selectively blocks beta-1 adreniergic receptors
Additional consequence:
Blocks beta 2
Normal hypotension but have vasoconstriction of brochioles –> might need to take a beta 2 agonist
ACE- angiotensin converting enzyme
RAAS
Angiotensin II –> vasoconstrictor and releases aldosterone –> more water retention –> more blood pressure
ACE inhibitor –> decreases pressure
Calcium channel blocker –> affects the heart directly
Diuretics
You are a drug designer and being asked to develop a drug that suppresses salivary and bronchial secretion before surgery. Based on todays’ information you would develop a drug that….
EXAM QUESTION
selectively blocks acetylcholine (ACh) at the muscarinic receptors, thereby blocking the parasympathetic effects. This drug (Atropine) is called a muscarinic antagonist.
Parasympathetic response (muscarinic) –> block muscarinic
Muscarinic antagonists- selectively block Ach at muscarinic receptors
Block NNJ –> paralyse skeletal muscles (keep patients calm and immobile during surgery)
If you wake up to early and skeletal muscles are being paralysed What do you do?
Can be monitored now (in the past it was a problem)
You are a drug designer and being asked to develop a drug that dilates bronchioles in the treatment of asthma without undesirably stimulating the heart. Based on todays’ information you would develop a drug that….
EXAM QUESTION
selectively activates β2 adrenergic receptors at low doses thereby relaxing the bronchial smooth muscles (the heart has mostly β1 adrenergic receptors). This drug (Salbutamol) is called a β2 agonist.
Asthma- inflammatory disease of small airways (early dynamic small airway closure)
- Beta 2 agonist (activates receptors in small airways –> bronchiole dilation)
- Reliver
- Too many puffs of puffer (high dose)
- Increase HR (overflows –> reaches heart –> activates Beta 1 receptors)
- Immediate (when need relieving)
- Steroids (anti-inflammatory in small airway –> dilate)
- Not an immediate effect –> few days
You are a drug designer and being asked to develop a drug that increases heart rate and that leads to general vasoconstriction in the treatment of acute cardiac failure. Based on todays’ information you would develop ….
EXAM QUESTION
Human adrenaline. Adrenaline activates α & β adrenergic receptors thereby increasing heart rate, and promoting smooth muscle contraction of peripheral arterioles, which results in increased arterial blood pressure.
Adrenaline and noradrenaline activate alpha1 and alpha1 (which need to be activated to increase HR and vasoconstriction)
Drug - Adrenaline (used in epi pens)
if anaphylaxis –> vasodilation –> decrease pressure –> adrenaline –> general vasoconstriction
You are a drug designer and being asked to develop a drug that reduces the effects of both, sympathetic and parasympathetic NS. Based on todays’ information you would develop a/an:
- non-specific adrenergic antagonist
- muscarinic antagonist
- muscarinic agonist
- nicotinic agonist
- nicotinic antagonist
EXAM QUESTION
- nicotinic antagonist
