Lec 12 Flashcards
Where can Herpies Zoster/chicken pox lie in our body,
what does it become?
criteria for getting shingles
Lie in dorsal root ganglion
become shingles
must have had pox before getting shingles
What is postherpetic neuralgia?
pain in the nerves that persists weeks after having shingles.
What are the symptoms of shingles
loss of pain, temp, crude touch (so antero-lateral path)
What is tabes dorsalis
symptoms
slow degen of dorsal columns, roots, and ganglia in spinal cord (typically lumbar region)
it’s the late symptoms of untreated syphilis (10-30 years after)
symptoms: proprio loss, parasthesias, allodynia, tabetic gait
what is parasthesias
abnormal sensation that occurs without an external stimulus.burning, tingling etc.
what is allodynia
condition where person feel pain with no stimulus
what is a neuropathy
name two types of neuropathies and short description
nerve disorder
Mononeuropathy - single peripheral nerve is damaged
Polyneuropathy - multiple peripheral nerves damaged
usually from:
- diabetes
- Overdose of pyridoxine (vit B6)
- Ganglionopathies (disorders affect dorsal root ganglia)
- polyneuritis (inflammation of multiple peripheral nerves)
Describe traits of diabetic neuropathy
- typically affect distal limbs
- glove and stocking pattern (bilateral)
- paresthesis/allodynia
- poor blood supply/inflammation
- about 60% of ppl with diabetes will get
OD of pyridoxine (vit B6)
describe traits of this
it is neurotoxic if take too much so develop neuropathy.
- (>200mg)
- affect large myelinated fibres (1a afferents)
- can be irreversible if goes on for too long
describe traits of ganglionopathies
autoimmune response to something else but ends up attacking ganglions
describe traits of polyneuritis
inflammation of multiple peripheral nerves.
what is the vestibular system
system in your inner ear responsible for balance and acceleration detection
how does it rest within the skull?
there are bony labyrinths/canals in the skull that are filled with perilymph fluid (peri = around)
then floating in that is the membranous inner structure filled with endolymph fluid (endo = inside)
What are the otolith organs? describe in good detail
organs are utricle and saccule which both consist of a macula.
Utricle does the horizontal plane and saccule does the vertical plane
what type of accelleration does each detect (otolith vs canals)
linear accel
the canals detect angular accel
which way do the hairs point in the utricular macula vs the saccular macula?
arrows point to what direction excites the organ
ut - arrow point inwards therefore kinocillium point towards striola (centre) and steriocillia point out.
sac - arrows point outwards therefore steriocillia point inwards and kino point out (from striola)
what are the 3 semi-circular canals
anterior
posterior
horizontal/lateral
what does the cochlea do?
what nerves innervate the cochlea and the vestibular canals
cochlea for hearing
CN VIII innevate vest syst and cochlea
superior vestibular ganglion innervate utricle and rest of vestibular system
inferior vestibular ganglion connect to saccule
cochlear nerve innervate cochlea
what is at the end of each semi-circular canal, describe in depth the parts and how it works
- ampulla is at end
- the mechanism inside amp is a crista (also called crista ampullaris).
- within that is a cupula (like a sail that gets pushed by fluid)
- inside the cupula are the hair cells that have the cillia.
Hair cells continuously discharge at what rate
100 Hz
allows to depol or hyperpol
difference between polyneuritis and polyneuropathy
polyneuropathy - mult nerves affected by disorder e.g. diabetic
polyneuritis - inflammation of multiple nerves
