Autonomic nervous system recap Flashcards
The autonomic nervous system is a division of what? (2)
peripheral nervous system
efferent nervous system
Sympathetic nerves have which type of outflow
Thoracolumbar outflow
Short preganglionic fibres and long post ganglionic fibres
Where are sympathetic ganglia located?
Paravertebral ganglia (sympathetic chain running up and down spinal cord)
Prevertebral ganglia
In the sympathetic system, what are the synapses between pre and post ganglionic cells?
Cholinergic (Ach - neurotransmitter)
then Nicotinic receptor
In the parasympathetic system, the synapses between pre and post ganglionic cells are of what type?
Cholinergic and nicotinic
In the parasympathetic system the synapses between the post ganglionic cells and their targets are of which type?
Cholinergic (Ach)
Muscarinic receptor - acts on muscle
Post ganglionic cells in the adrenal medulla (4)
Release adrenaline
Have no axons - just release hormone/neurotransmitter into the blood
Are part of the sympathetic system
Contribute to mass activation - acts on adrenergic receptors throughout the body as hormone is in the blood
What type of receptors do adrenaline and Noradrenaline act on?
Adrenergic
Alpha
Beta
Acetylcholine acts on which type of receptors?
Nicotinic - integral ion channel
Muscarinic - G protein coupled (second messengers)
Adrenergic transmitters?
adrenaline
noradrenaline
Cholinergic transmitter
Acetylcholine
What does activation of the sympathetic system in the eye cause?
THINK FIGHT OR FLIGHT REACTION
Contraction of radial muscle of the iris = You want to dilate pupil to see more - Sym Noradrenaline on alpha 1 receptors
Relaxation of the ciliary muscle surrounding the lens = you want to be able to see far away - Sym Noradrenaline on Beta 2
What does parasympathetic activation cause in the heart?
Decrease in heart rate -
Release of Ach - parasympathetic releases that here
stroke vol not affected as fibres don’t innervate ventricles much
In some blood vessels, activation of the sympathetic system causes vasodilation because…
They express beta 2
What is different about your Salivary glands and genitalia?
they are innervated by parasympathetic but most other blood vessels aren’t
Alpha 1 receptors cause what?
constriction of vessels
Beta 2 receptors cause what?
relaxation of smooth muscle
Skeletal and cardiac muscles have lots of which type of receptors
Beta 2
also have alpha 1 but more B2
How does activation of the sympathetic system affect the lungs?
Relaxation of smooth muscle around the airways- relax airways to get more O2 down into the lungs. A/NA on Beta 2
central resp centres affect things like rate of breathing etc
What can autonomic neuropathy cause? (3)
Syncope
Bladder problems
Bowel problems
Name some common tests of autonomic function (3)
Cardiovascular response to deep breathing (heart rate changes - vagus nerve affects HR)
Size of CVS response to these shows sympathetic side:-
Valsalva manoeuvre - changes in BP
Tilt test - Changes in BP
