Autonomic Nervous System Flashcards
What does the autonomic system control
Viscera of the body so involuntary response
What i the name of the autonomic system that works in conjunction with the central nervous system to regulate the digestive system
Enteric nervous system
What kind of response does the sympathetic system elicit
Increase in activity time of stress fear and anxiety
Increase in BP, blood sugar, redirection of blood flow to skeletal and way from viscera.
Also causes dilation of pupils and decrease in saliva as body directs attention away from digestive tract
What responses does the parasympathetic system elicit
Targets viscera, abdomen and pelvis
Decrease in CO,speeds up peristalsis in GI tract and increases salivation
It promotes digestive processes and causes pupillary constriction
Autonomic pathways are efferent and consist of how many neurons which synapse ina ganglion
2
Pregnaglionic are myelinated and post ganglionic are not
Which preganglionic neuron tends to be shorter, sympathetic or parasympathetic?
Sympathetic are shorter and are closer to the CNS than those of parasympathetic divsion
Which are the two Neurotransmitters used in the ANS and which kind of response do they have
Acetylcholine and noradrenaline
They both have excitatory posynaptic effects
The release of ACH from the postganglionic parasympathetic neurons causes what..
Increase in gut motility and decreases cardiac muslce contraction
What is the fibre called if it resales ACH
Cholinergic fibres
What is the fibre called if it releases noradrenaline
Adrenergic fibres
What is noradrenaline involved in
It is involved in the wakefulness and attention
It’s postngalgion sympathetic fibres to internal organs and most blood vessels use noradrenaline to decrease gut motility and increase cardiac muslce contraction
Where is the origin of PARASYMPATHETIC preganglionic neuuron cell bodies.
Is from the nuclei in the brainstem and cn3,7,9,10
And from the sacral spinal cord and nerves S2-4
They travel to ganglia located close to their target organ
What is the location of the SYMPATHETIC pregnalionic neurones
Spinal segments T1-L2. Specifically in lateral horn
Which type of ganglia form the sympathetic chain?
Paravertebral ganglia form the sympathetic chain
Where do the meet left and right sympathetic chains join?`
Ganglion impair, sits in front of sacrum
How is the stellate ganglion formed?
The C7 and T1 ganglia fun to form large ganglion
Where do the sympathic neurons leave the spinal cord and how do they enter the sympathetic chain
Leave the spinal cord via the ventral root( Carry’s motor fibres)
From part of a spinal nerve
Enter the ganglia of the sympathetic chain via the white ramps communications
Once the preganglionic neurons have entered the symphathetic chain what are the three courses they can take?
- Synapse with the ganglia at the same level; with a postganglionc Neuron from grey matter ramus
2.Travel up or down chain to synapse in a ganglion at a different level with post ganglion neurons that exit via grey ramus communicans
- Exit the ganglia via a splanchnic nerve to a prevertabral ganglion where it will synapse with a post ganglionic neuron
If the sympathetic preganaglionic neuron is destined for the head what will it do when it gets into the chain
It will ascend the sympathetic trunk and synapse in the superior cervical region.
From here the post ganglionic fibres will travel into the head region and along surfaces of internal carotid artery and carotid plexus
If the sympathetic post ganglionic neuron is destined for the trunk and limps where will it synapse
It will synapse in the ganglia of the sympathetic chain and send post ganglionic fibres via gray rami communicans to be distributed with the spinal nerves to target tissue
If the sympathetic preganglionic neurons are to go to the abdomen and pelvis, how do they do this, do they synapse
NO these axons travel through the chain without synapsing and they will proceed via splanchinc nerves to specific prevertebral ganglia to sypnase with post ganglionic target neurons
Neurons of the sympathetic nervous system begin in the thoracolumbar region and so must ascend to reach the head and neck, which trunk is the continuation of the thoracic sympathic trunk
The Cervical sympathic trunk
The cervical ganglia are where the preganglionic neurons synapses in the head and neck before hitch hiking with arteries to reach their target, where are these cerival ganglions ?
Superior cerivcal ganglion - C1/2
Middle - C6
Inferior - C7
How do the post ganglionic axons form the superior cervical ganglion arch their target organs
By forming a plexus around the common carotid artery and its branches
What do the cervical ganglia regulate sympathetic innervation of;
Eyes ( pupil dilation), eyelids, lacrimal glands, Carotid body, salivary and sweat glands
What is Horner’s syndrome?
Damage to the cervical sympathetic trunk resulting in absence of the sympathetically stimulated functions on the ipsilateral side of the head
What are the three common signs of Horners syndrome
Miosis, ptosis, flushed face and anhydrosis
What is miosis
Constriction of the pupil because the parasympathetically stimulated sphincter of the pupil is unopposed
What is ptosis
Drooping of superior eyelid
Why do you get a flushed face and anhydrosis( little or no sweat) in horners syndrome
Caused by the lack of sympathetic ( vasoconstrictive ) nerve supply to the blood vessels and sweat glands
If a pregnaglionic neuron does not synapse in the sympathetic chain what does it exit as and where will they synapse
Splanchnic nerve - these will go onto synapse with postganglionc neurons in prevertebral ganglia
What kind of neurons is the adrenal medulla supplied by
Sympathetic pre-ganglionic neurons
Which kind of cells do the preganglionic sympathetic fibres synapse with in the adrenal medlla
They synapse with the chromaffin cells which release adrenaline and noradrenaline into the blood stream
Discuss the parasympathetic innveration of the oculumotor nerve
Preganglionic - neurons travel from Edinger-Westphalia nucleus in the brain to the ciliary ganglion
Postganlionic - neurons travel to innervate ciliary muscle and sphincter pupillae
Discuss parasympathetic innervation of the facial nerve
The neurones from the facial nerve synapse with the ptergoplataine and submandibular ganglion
Postganglionc from ptergoplalatine go to lacrimal gland and nasal mucosa via the greater petrosal. Nerve
Postganglionic from submandibular ganglion go to submandibular gland via the chorda tympani
Discuss the parasympathetic innveration of cn9
The preganglionic parasympathetic neurons from CN9 synapse with the otic ganglion
The post ganglionic nerves then go to the parotid gland via the auricotemporal nerve
Make note on where all the ganglia lay
Does the CN10 provide parasympathetic supply to the head and neck
No but to abdomen and thorax
Discuss the parasympathic innervation of the cn10
Presynaptic neurons travel rom the dorsal nucleas of the vaugus nerve to the nucleus ambiguous
Within the carotid sheath
Then synapses with the postganglionc fibres in the ganglia close to or within the target organ
Which kind of muscle is the nucleus ambiguous (in the vagus nerve) for specifically
Cardiac muslce - these nerve fibres then travel with the vagus nerve from the carotid canal to the arch of the aorta.
