QuestionSBA
QuestionChoice
This is found within the brain and contains dopaminergic neurones.

Dopamine within this structure are lost in Parkinson's disease and can cause rigidity, tremor and slow movements/ bradykinesia.
10005784
d
Substantia nigra
QuestionChoice
This is affected by the condition Horner's syndrome which presents with the triad of miosis, ptosis and anhidrosis.

A lesion anywhere along this lesion can cause these symptoms.

Not an autoimmune condition. Can be caused by a pancoast tumour in the lungs.
10005782
b
Oculosympathetic pathway
QuestionChoice
This case is describing the presentation of Myasthenia Gravis syndrome.

This is due to antibodies blocking the acetylcholine receptors at the neuromuscular junction.

This case may make you think about Bell's palsy - remember this would present asymmetrically and due to damage of the facial nerve (forehead is not spared in LMN lesion).
10005781
a
Acetylcholine receptor
QuestionChoice
This is not targeted in this condition.

Guillian Barre can cause demyelination following infections such as campylobacter. This is due to molecular mimicry - the antibodies produced in this infection can target and destroy myelin on neurones.

This presents with a symmetrical, ascending polyneuropathy (weakness and numbness).
10005783
c
Myelin sheath
QuestionChoice
Calcium channels are found within the pre-synaptic terminals. Calcium channels allow the influx of calcium which causes the release of Ach into the synapse of the neuromuscular junction.

These are affected by Lambert Eaton syndrome.

This causes proximal muscle weakness and typically occurs in small-cell lung cancer where antibodies target these channels.
10005785
e
Calcium channels
Concept
Chapter
2693
3859
Myasthenia Gravis
Topic
158
Immunology
13703
40 year old female presents with symmetrical weakness of the face.

Her clinic appointment was at 5pm.

On examination, she appears to have dry red eyes with ptosis and a drooping smile on both sides of her face. When asked to raise her eyebrows she is unable to do so.

She explains that she also experiences trouble chewing and swallowing and that it usually improves with rest and progressively worsens throughout the day.

What is affected by this autoimmune condition?
a