Autonomic nervous system Flashcards
How can we test the effects of sympathetic innovation on blood flow of the patient?
- Injection of local anaesthetic around the stellate gangllion
- preganglionic and postganglionic fibres are inactivated
- sympathetic paralysis in the head, neck and upper limb of that side
How is a successful stellate block demonstrated by
- warm, dry hand
- horners syndrome, constricted pupil
- ptosis (drooping) of the upper eyelid
what does it mean by negative effects of the cervical ribs (impinging of the cervical rib)?
- when the patient has extra ribs
- neurons normally pass through each ribs but patients that have extra cervical ribs the ganglian that stretch
What is Horner’s syndrome
- constricted pupils (MIOSIS)
- partial ptosis (DROOPING)
Anhydrosis (reduced sweating on the same side
The affected pupil reacts to light but responds and recovers very slowly
What is horners syndrome caused by?
- caused by paralysis of sympathetic neurons in the head, neck and upper limbs
- tauma
- tumour
- multiple sclerosis
- negative effect on the cervical ribs
What is the pathway of the postganglionic sympathetic neurons
happens after the preganglionic neronal pathway
- Synapses at the sympathetic ganglion in the sympathetic chain
- post ganglionic neurons depart via the grey ramus comminicans (unmyelinated)
- then goes via the dorsal ramus (supply the back body) or the ventral ramus (supply the anterior body)
What is the route of pre ganglionic neurones?
- departs from the lateral horn T1-L2
- passes through the ventral root
- efferent away from the lateral horn towards the effector organs
- Enters the sympathetic chain via the white ramus communicans (myelinated
What is the route of the neurones that cause pupil dilation and inhibit salvation
From the throacic spinal cord to the superior cervical ganglion
- Neurons can ascend or descend to another ganglion
- the one ASCENDS to superior superior cervical ganglion responsible for pupil dilation and inhibit salvation
where does the ventral ramus and dorsal ramus send neurons
ventral ramus sends neurons to FRONT of body
Dorsal ramus needs neurons to BACK of the body
Why does stellate block cause horners syndrome and dry increased temperature of arms
Stellate ganglion block causes sympathetic blockade of the ipsilateral face and arm (same side) . Therefore, a successful block produces an ipsilateral Horner’s syndrome (ptosis, miosis, and anhydrosis), flushing of the face, and increased temperature of the arm.
What are two muscles of the eyes and what do they do
- sphincter pupillae: contracts the pupil and decreases it in size
- dialator pupillae makes the eye bigger
What is miosis and mydriases
Mysriasis= dialated pupil- involves dialator pupillae Miosis= contractive pupil- involves sphincter pupillae
where does the oculomotor of the parasympathetic nervous system synapse
Comes from the mid brain and will synapse at the ciliary ganglion and result in pupillary constriction
Where does the facial nerve of the parasympathetic nervous system synapse
-From the pronto- medulary junction - (junction in ponds and medulla)
synpases in prontopalatine ganglion and supplies paratoid glands
- synapses in submandular ganglion and supplies the salivary glands
Where does the glossopharyngeal synapse and supply
From the medula and supplies the paratoid gland via the otic ganglian
