Autonomic nervous system Flashcards
Autonomic control is voluntary control or involuntary control
Involuntary
What parts of the body does autonomic system control (4)
Controls smooth muscle, cardiac muscle, glands, GI neurons
Sympathetic outflow
Thoracolumbar T1-L2
Ganglia are close to where in sympathetic nerves (2)
Close to spinal cord (paravertebral ganglia) or in collateral (prevertebral) ganglia
Pre-ganglionic sympathetic fibres release what neurotransmitter onto what type of receptor
ACh onto nicotinic receptor
Post-ganglionic sympathetic fibres release what neurotransmitter onto what type of receptor
Noradrenaline or adrenaline onto alpha or beta receptors (adrenergic receptors)
Noradrenaline or adrenaline are released into where from the adrenal medulla
Blood because there’s no post-ganglionic axon
Parasympathetic outflow
Crania-sacral CN III, VII, IX, X and S2-S4
ACh acts on what type of receptors + name the subcategories of this type of receptor (2)
Cholinergic:
Nicotinic (ionotropic)
Muscarinic (metabotropic)
Pre-ganglionic sympathetic fibres release what neurotransmitter onto what type of receptor
ACh on nicotinic receptor
Noradrenaline/adrenaline acts on what type of receptor + name the subcategories of this type of receptor
Adrenergic:
Alpha (metabotropic)
Beta (metabotropic)
Post-ganglionic sympathetic fibres release what neurotransmitter on what type of receptor
Noradrenaline or adrenaline onto adrenergic alpha or beta receptors
Post-ganglionic parasympathetic fibres release what neurotransmitter on what type of receptor
ACh onto muscarinic receptors (cholinergic receptors)
Sympathetic and parasympathetic system produces what kind of effect
Sympathetic - co-ordinated
Parasympathetic - independent
Effect of sympathetic system on the eye (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the eye
Noradrenaline activates b2 receptors on ciliary muscle round lens
–> ciliary muscle relaxes & eye focuses far away
Noradrenaline activates a1 receptors on radial muscle of iris (dilator pupillae) –> radial muscle contracts & makes pupil larger
Effect of parasympathetic system on the eye (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the eye
ACh activates muscarinic receptors on ciliary muscle –> ciliary muscle contracts & eye focuses close up
ACh activates muscarinic receptors on sphincter muscle –> contracts sphincter muscle & makes pupil smaller
Effect of sympathetic system on the heart (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the heart
NA activates b1 receptors on pacemaker cells –> Increases heart rate
NA activates (mainly) b1 receptors on myocytes –> Increases strength of contraction
Effect of parasympathetic system on the heart (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the heart
ACh activates muscarinic receptors on pacemaker cells –> decreases heart rate
ACh has little effect on myocytes –> Little effect on strength of contraction
Effect of sympathetic system on the lungs (1)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the lungs
NA activates b2 receptors on smooth muscle of airways –> makes smooth muscle relax & dilates airways
Effect of parasympathetic system on the lungs (1)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the lungs
ACh activates muscarinic receptors –> makes smooth muscle contract & constricts airways
What would a b2 agonist do to the lungs and heart
Dilate airways
No effect on heart
What effect would a b1 antagonist have on the heart
Decrease heart rate
Effect of sympathetic system on blood vessels (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the blood vessels
NA activates a1 receptors on smooth muscle of vessels –> makes smooth muscle contract & blood flow decreases
NA activates b2 receptors on smooth muscle of vessels–> makes smooth muscle relax & blood flow increases
Effect of parasympathetic system on blood vessels
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the blood vessels
No effect
Effect of sympathetic system on the gut (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the gut
NA activates a/b receptors on smooth muscle of gut –> decreases gut motility
NA activates alpha receptors in pancreas –> inhibits secretion of enzymes
Effect of parasympathetic system on the gut (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the gut
ACh Activates muscarinic receptors on smooth muscle of gut –> increases gut motility
ACh Activates muscarinic receptors in pancreas –> Increases secretion
Effect of sympathetic system on energy stores (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the energy stores
NA Activates a/b receptors on liver cells (hepatocytes)
–> stimulates glycogenolyis & gluconeogenesis
NA Activates a/b receptors on fat cells (lipocytes)
–> increases lipolysis
Effect of parasympathetic system on energy stores
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the energy stores
No effect
Effect of sympathetic system on salivary glands (1)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the salivary glands
NA Activates b receptors
–> Stimulates thick secretion rich in enzymes
Effect of parasympathetic system on salivary glands (1)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the salivary glands
ACh Activates muscarinic receptors
–>Stimulates profuse watery secretion
Effect of sympathetic system on the bladder (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the bladder
NA Activates b2 receps on smooth muscle of bladder wall
–> Relaxes smooth muscle and reduces pressure
NA Activates a1 receptors on smooth muscle of sphincter
–> Contracts smooth muscle and stops urination
Effect of parasympathetic system on the bladder (2)
-describe what neurotransmitter is released and what specific receptors are activated and the effect created on the bladder
ACh Activates muscarinic receptors on bladder wall
–> Contracts smooth muscle and increases pressure
ACh Activates muscarinic receptors on sphincter
–> Relaxes smooth muscle and causes urination
What organs receive dual innervation (i.e. both sympathetic and parasympathetic) and have antagonistic actions
Eye
Heart
Gut tube
Bladder
Describe the pre-ganglionic and postganglionic fibres of sympathetic nerves
Short preganglionic
Long postgagnlionic
Cranial nerves that contain parasympathetic fibres are (4)
III
VII
IX
X
Synapses between post-ganglionic parasympathetic fibres and their targets are (2)
Cholinergic and muscarinic
Features of post-Ganglionic fibres in the adrenal medulla(4)
Release NA/adrenaline
Have no post-ganglionic axons
Part of sympathetic system
Contribute to mass activation
In fight or flight, you want the eyes to… (2)
Dilate pupils
Focus far away
Eye drops to dilate pupils may contain what (2)
a1 agonist
muscarinic antagonist
Parasympathetic activation of the heart does not decrease what
Stroke volume
Some blood vessels vasodilate when activated by sympathetic nerves because they express what receptors
b2
