Autonomic Physiology 1 Flashcards
What structures does the autonomic system control in the body?
- Smooth muscle in blood vessels
- Smooth muscle in bladder
- Gut
- Sex organs
- Secretions
- Focussing of the eye
Do sensory nerves differ between the somatic and autonomic nervous system?
No
How do efferent nerves differ from the somatic system?
They don’t have a single axon body to the target but have a synapse between it (at a ganglion)
How does the pre ganglionic fibre differ from the post?
It is myelinated whereas the post ganglionic fibre is unmyelinated.
What are the 3 subgroups of the ANS?
- Sympathetic
- Parasympathetic
- Enteric
What is the synapse between a nerve and a muscle called?
Neuromuscular junction
What ion channels are present at the NMJ?
Ionotropic
What response is ALWAYS generated by a NMJ?
Excitatory
What receptors exist at the synapse between autonomic and the target?
Metabotropic (g protein coupled)
What responses can be produced by a synapse between the autonomic system and its target?
Excitatory or inhibitory
What name is given to the nerves involved in the parasympathetic system?
Cranialsacral
What is the “main” nerve involved in the parasympathetic system?
Vagus nerve
What structures does the vagus nerve control?
- Heart
- Lungs
- Stomach
- Intestines
What structures do the parasympathetic sacral nerves control?
- Lower colon
- Sex organs
- Bladder
Which ganglionic fibre is longer in the parasympathetic system?
Pre ganglionic is longer than post
Where can the ganglion sometimes be found in the PNS?
In the target
What neurotransmitter do the pre ganglionic fibres in both the sympathetic and the parasympathetic release?
Acetylcholine
What receptors does this ACh act on?
Nicotinic
What neurotransmitter do the post ganglionic fibres release in the PNS?
Acetylcholine
What receptors does this post ganglionic ACh act on?
Muscarinic
Whats the name given to the nerves involved in the sympathetic system?
Thoracolumbar
What is the difference between length of pre and post ganglionic fibre
Pre ganglionic short post ganglionic long
What is the name given to ganglia right beside the vertebrae?
Paravertebral Ganglia
What’s special about the celiac and mesenteric nerves?
They synapse further away from the spinal cord.
What is the white ramus?
Pre ganglionic fibre (myelinated)
What is the grey ramus?
Post ganglionic fibre (unmyelinated)
What neurotransmitter do post ganglionic synapses of the sympathetic system release?
Noradrenaline
What receptors does noradrenaline work on?
Adrenergic - alpha and beta
What is another role of noradrenaline and adrenaline in the sympathetic response?
Secreted as a hormone by the pancreas which still acts on alpha and beta receptors.
