Autonomic Nervous System Flashcards
What is the ANS a division of?
the peripheral and efferent nervous systems
What is the ANS?
involuntary and has 2 parts: parasympathetic and sympathetic
What is the outflow of the 2 parts?
sympathetic nerves have throacolumbar outflow
parasympathetic nerves have craniosacral outflow
Describe the lengths of fibres for the parasympathetic and sympathetic divisions.
sympathetic= short preganglionic and long postganglionic fibres parasympathetic= long preganglionic and short postganglionic fibres
Where are sympathetic ganglia located?
prevertebral or paravertebral (sympathetic chain) ganglia
What are the cranial nerves that contain parasympathetic outflow?
oculomotor, facial, glossopharyngeal and vagus nerves (3,7,9,10)
What are the neurotransmitters and receptors between the pre and post-ganglionic cells?
for both sympathetic and parasympathetic the neurotransmitter is acetylcholine on a nicotinic receptor
What are the neurotransmitters and receptors between the post-ganglionic and targets?
parasympathetic= acetylcholine on muscarinic receptors sympathetic= non-adrenaline on adrengeric receptors (alpha and beta)
what is the exception of the adrenal medulla in the sympathetic division?
post-ganglionic cells in the adrenal medulla release adrenaline- they have no axons and contribute to mass activation as adrenaline is released into the blood so acts on all receptors
What effect does the sympathetic system have on the eye?
contraction of the radial muscle of the iris and relaxation of the ciliary muscle surrounding the eyes= dilation of the pupil and long focus
what effect does the parasympathetic system have on the heart?
decreases heart rate
what effect do the parasympathetic and sympathetic systems have on blood vessels?
sympathetic= vasoconstriction and in skeletal and cardiac muscle express beta 2 receptors which cause vasodilation parasympathetic= normally no effect except in genitalia and salivary glands where it causes vasodilation
What does activation of the sympathetic system do to the lungs?
relaxation of smooth muscle
What can autonomic neuropathy cause?
Syncope, bladder and bowel problems
What tests of autonomic function can be used for the diagnosis and progress of disease?
cardiovascular response to deep breathing, valsalva manoeuvre and tilt test
