Control L14 autonomic nervous system Flashcards
What are the two parts of the autonomic nervous system?
Sympathetic and parasympathetic
What is the role of the somatic division of the nervous system?
Connect us to our external environment via senses and to initiate muscle movement
What is the role of the autonomic nervous system?
control of internal activities of organs and glands which are largely involuntary and homeostasis
What part of the brain influences the autonomic nervous system rostrally?
Hypothalamus
What is the difference between parasympathetic and sympathetic activity?
Parasympathetic is rest and digest and sympathetic is fight or flight
What fibres make up the autonomic nervous system?
Visceral motor
Visceral sensory
What is the role of visceral motor fibres?
Efferent fibres to communicate between the nervous system and smooth muscle, cardiac muscle or glands
What is the role of visceral sensory fibres?
Afferent fibres to connect the nervous system to sensory receptors in an internal organ
What segmental spinal and cranial nerves are autonomic fibres found in?
Segmental Spinal = T1-L2 and S2-S4
Cranial = III, VII, IX and X
Where do visceral efferent motor fibres exit the spinal cord?
Lateral grey horn
Where do visceral afferent sensory fibres enter the spinal cord?
Dorsal root of spinal nerve (follow somatosensory afferent nerve fibres)
Which nerve fibres are responsible about referred pain?
Autonomic afferent fibres
What is referred pain?
When pain sensations from visceral organs are perceived as pain from regions of the body surface that are innervated by the same spinal nerves
How/why do we get referred pain according to one theory?
As somatosensory and visceral sensory afferent fibres use the same pathway to enter the CNS so the brain interprets the pain as coming from the respective skin region
How many neurones are involved in the autonomic visceral efferent pathway?
2
Where is the cell body in the pre ganglionic and post ganglionic neurones of visceral efferent fibres?
Pre ganglionic = cell body in brain stem or spinal cord
Post-ganglionic = cell body in pns at point of synapse with the pre ganglionic neurone
What is the cell body of the post ganglionic neurone in the visceral effect pathway known as?
Autonomic ganglion
What keeps the antagonistic effects of the sympathetic and parasympathetic divisions balanced?
Homeostasis
What is the sympathetic autonomic nervous system like anatomically?
Has thoracolumbar outflow from spinal nerves T1-L2.
Has its autonomic ganglia organised into sympathetic chains and prevertebral ganglia
What is the effect of the sympathetic autonomic nervous system compared to the parasympathetic autonomic nervous system?
Sympathetic has a widespread effects so one nerve impulse can affect multiple organs at once where as parasympathetic has a localised effect so each organ tends to need separate innervation.
What is the parasympathetic autonomic nervous system like anatomically?
Has craniosacral outflow from brainstem in CN III, VII, IX and X and spinal nerves S2-S4
Ganglia are found near effector organ.
What is the origin of parasympathetic nerves described as?
Cranio-sacral origin
What neurotransmitter is secreted by the pre ganglionic and post ganglionic neurones at the synapses within the parasympathetic division?
Acetylcholine
How are the axons of the post ganglion described compared to the axons of the pre ganglionic neurones?
Pre ganglionic = long axons
Post ganglion = short axons (as autonomic ganglion is near the effector)
