Organisation of the Autonomic Nervous System Flashcards
What are the sensory inputs to the ANS
Stretch receptors
Chemoreceptors
Osmoreceptors
What are the motor outputs in the ANS
Smooth Muscle
Cardiac muscle
Secretory glands
Why cant we always be innervated by the sympathetic nervous system
Expensive to maintain as a lot of info to brain and blood to skeletal muscle
Where do preganglionic fibres arise from in the Sympathetic division
Lateral horn of T1-L2
What is the ratio of lengths of preganglionic fibres to post ganglionic fibres in Sympathetic
Short Pre
Long Post
What is the difference between pre ganglionic fibres and post ganglionic fibres
Pre
- Cell body in brain or SC
- Myelinated axon
- Synapses in ganglion
Post
- Cell body in autonomic gangliokn
- Axons unmyelinated
- Synapses on target
Where do preganglionic fibres arise in the parasympathetic division
Brainstem and sacral cord
Where is the ganglia in the sympathetic division
Close to SC = Symphathetic chain
Where is the ganglia in the parasympathetic division
Close to target tissue
What is the ratio of lengths of preganglionic fibres to post ganglionic fibres in Parasympathetic
Long pre
Short post
Where do sympathetic afferents go through
Sympathetic ganglion to DRG on same level
Where do parasympathetic afferents go through
Cranial nerve sensory nuclei to DRG to dorsal horn at sacral level
Why is organ pain interpreted as skin pain
Visceral and somatic fibres pass through same spinal nerve
What kind of pain is described in afferen fibres
Poorly localised and described
What is Horners Syndrome
Pressure on sympathetic chain so unopposed parasympathetic supply to face causing miosis, ptosis, red dry skin
