Flashcards in Nervous System Deck (44)
What are signs of Frey syndrome?
Gustatory sweating of face
What are the actions of the sympathetic nervous system?
Raises heart rate
Increases force of contraction
Constricts most blood vessels
Slows GI transit
Dilates pupil (mydriasis)
Secretion of seminal fluid/movement of sperm
What are the actions of the parasympathetic nervous system?
Slows heart rate (no effect on force)
Relaxes blood vessels
Speeds up GI transit
Constricts pupil (miosis)
What are dendrites?
Receptive projections sensitive to neurotransmitter input
What is the soma of a neuron?
What is an axon?
One-way rapid communication between cell body and axon terminals
What is an axon terminal?
Form connections with other neurons/effector tissue via synapses
What makes up the CNS?
Brain, spinal cord, retina & CNII
What makes up the PNS?
Spinal & cranial nerves (all except CNII)
Autonomic nervous system
Somatic sensory and motor nerves
What are the 3 branches of motor output?
Somatic motor - skeletal muscle
Brachio motor - pharyngeal arch muscle
Visceral/autonomic motor - organs and vessels
What are the 3 branches of sensory input?
Somatic sensory - sensations from somatic tissue
Visceral sensory - sensations from organs and vessels
Special visceral sensory - taste
At what levels of the spinal cord is a lateral horn seen?
T1-L2 and S2-4
Where do neurons controlling lateral horn cells (or autonomic brainstem nuclei) arise?
Where does the sympathetic chain extend up to and finish?
Near base of skull
Ends at tip of sacrum
Which branch of the ANS would be damaged by vertebral damage at L1 level?
What does the sympathetic chain communicates with spinal nerves via?
What is the difference between grey and white rami communicans?
White = preganglionic sympathetic neurons passing into chain
Grey = postganglionic sympathetic neurons passing from chain into spinal nerve
Give examples of nerves which emerge from the sympathetic chain
Thoracic and cardiac splanchnic nerves
What is a dorsal root ganglion?
Cell bodies of sensory neurons
At what levels are white rami communicans seen?
At what vertebral levels are grey rami communicans seen?
Where can brainstem or spinal cord injury proximal to T1 cord level affect supply to?
Sympathetic supply to head
Describe the sympathetic supply to the face
Reticulospinal tract neurons originate in brainstem/hypothalamus
Descend to T1 & synapse with preganglionic neuron in lateral horn
Exit cord with T1 spinal nerve
Travel to sympathetic chain
Run up chain to cervical ganglia & synapse with postganglionic neuron
Postganglionic neurons enter head as plexus around internal carotid artery
Supply face via external carotid artery
What are the 3 sympathetic chain ganglia in the neck?
Superior cervical - C1-4
Middle cervical - C5-6
Stellate - C7-T1, near lung apex
What are sympathetic nerves in the head distributed with?
Cranial nerves and arteries
Describe the distribution of the superior cervical ganglion to the face
Sympathetic neurons form a plexus around the internal carotid artery which join parasympathetic nerves
Distributed with arterial branches
Forms deep petrosal nerve which joins parasympathetic greater petrosal nerve and CN VII
Run to pterygo-palatine ganglion from which they are distributed
Distributed with branches of CN V
What can be the effects of a pterygo-palatine fossa tumour?
Can compress pterygo-palatine ganglion causing loss of sympathetic and parasympathetic innervation to the face
What does loss of sympathetic supply to the head lead to?
Uneven pupil size / Pupil constriction (miosis)
Ptosis - eyelid droop
Lack of sweating (anhydrosis)
Which cells of the adrenal medulla release adrenaline?