Lecture 12 Flashcards
Where do efferents end in the autonomic nervous system?
Smooth muscle, cardiac muscle and secretory tissues
ANS efferents have two neurones linked by?
Peripheral synapse
What do visceral afferents of the ANS provide?
Information to the CNS
What are the divisions of the ANS?
Sympathetic NS and Parasympathetic NS
What system is the fight or flight?
Sympathetic NS
What does the sympathetic NS involve?
Heart, arterioles, skin, lungs, gut, pupils and liver
In the SNS, what happens to the heart?
Increases heart rate
In the SNS, what happens to the arterioles?
dilutes or constricts
In the SNS, what happens to the skin?
Makes hair stand on end/produces sweat
In the SNS, what happens to the lungs?
Dilates bronchioles
In the SNS, what happens to the gut?
Reduces motility/closes sphincters
In the SNS, what happens to the pupils?
Dilates
In the SNS, what happens to the liver?
Releases glucose
What system is the rest and digest?
Parasympathetic NS
What organs does the parasympathetic NS supply?
Heart, Lungs, Gut, Pupils and Liver
What nerves do not synapse the sympathetic chain?
Splanchnic nerves
Where are preganglionic sympathetic neurons found?
In the lateral horn of the spinal cord from T1-L2
Grey rami communicantes contain?
Unmyelinated axons of postganglionic axons
White rami communicantes contain?
Myelinated axons of preganglionic axons
What are the different trajectories of preganglionic sympathetic fibres exiting the spinal cord?
Enter the sympathetic chain, ascend and synapse.
Enter the ganglion and synapse at the same level
Enter the sympathetic chain, descend and synapse
Pass through the sympathetic chain without synapsing, enter abdominopelvic splanchnic nerve, synapse in one of several prevertebral ganglia and synapse
What is a modified sympathetic ganglion?
Adrenal medulla
What do the postganglionic neurons lack and deliver?
Lack axons and deliver adrenaline and noradrenaline into local vasculature
What nerves are parasympathetic nerves?
3, 7, 9 and 10
Areas associated with sympathetic activation?
Posterior nucleus and dorsomedial nucleus
Areas associated with parasympathetic activation?
Anterior nucleus
What does the hypothalamus control?
Body temperature, satiety and water intake
Where does the hypothalamus receive afferents from?
Cortex, hippocampus, amygdala, spinal cord and brainstem
How does hypothalamic efferents reach the preganglionic autonomic neurons?
Synapses in the reticular formation
Where are cell bodies of the visceral afferents located?
In the dorsal root ganglia
What do pain afferents usually travel with?
Sympathetic fibres
What do afferents carrying physiological information travel with?
Parasympathetic fibres
