Nerve Condution And Synapses

Question 0

Decreased conduction velocity

Answer 0

Typically demyelination
Multiple sclerosis (inflammatory) - motor, sensory function affected
Guillain-Barré syndrome (autoimmune, campylobacter jejuni) on myelin sheath, imitated by food poisoning, feeling of paralysis from most distant limbs to trunk --> all PNS affected

Question 1

Botulinum toxin

Answer 1

Can cause food poisoning: ‘botulism’
Therapeutically to treat conditions –> muscle spasm, cervical dystonia, cerebral palsy
Relieve excessive sweating
Reduce appearance of wrinkles

Question 2

Myasthenia gravis

Answer 2

Autoimmune neuro-muscular disease leading to progressive skeletal muscle weakness and fatigue ability
Caused by auto-antibodies against nAChR at NMJ that interfere with NMJ threshold:
> sterically preventing ACh binding
> cause nAChR internalisation and degradation
> precipitate formation of immune system complement membrane attack complex, thus damaging muscle cell membrane
Immunosuppressants, surgical removal of thymus, AChE inhibitors, removal of anti-AChR anitbodies from blood (plasmapheresis)

Question 3

Prozac

Answer 3

Positive effect
Inhibits serotonin re-uptake by blocking serotonin transporter
Serotonin: mood and anxiety
Major depression, panic disorders, OCD

Question 4

Cocaine

Answer 4

Inhibits dopamine re-uptake by blocking dopamine receptors

Motivation and reward –> addiction

Question 5

Ritalin

Answer 5

Inhibits monoamine re-uptake by blocking noradrenaline and dopamine transporters
Used to treat ADHD

Question 6

Antimuscarinic drugs

Answer 6

Asthma - ipratropium by inhalation, lungs
Bradycardia - Atropine
Decrease secretions and AChEI side effects during operations - atropine
Dilate pupils - tropicamide

Question 7

Alzheimer’s disease

Answer 7

Symptoms: progressive dementia
Diagnosis: exclusion of other causes (particularly vascular, depression, hypothyroidism)
Treatment: AChE / nicotinic allosteric potentiating Ligands eg rivastigmine