QuestionSBA
QuestionChoice
Noradrenaline receptors are responsible for producing an adrenergic effect when stimulated. These effects include an increase in heart rate, increased blood pressure, bronchodilation, and constriction of the pupils. Noradrenaline does not affect the eyelid muscles or the jaw - therefore damaging these receptors is unlikely to cause isolated symptoms of eye and jaw muscle weakness.
10001746
e
Noradrenaline (NA) receptors
QuestionChoice
This patient is experiencing weakness in her skeletal muscles - specifically her eye and jaw muscles. This is what is causing the drooping of her eyelids. This is the classical presentation of myasthenia gravis, an autoimmune condition.

ACh (acetylcholine) receptors are found at the neuromuscular junction and are responsible for skeletal muscle contraction. An autoimmune attack in the form of autoantibodies against these receptors would be consistent with the signs and symptoms reported by this patient.
10001742
a
Acetylcholine receptor
QuestionChoice
GABA receptors are responsible for inhibiting the stimulation of nerves in the central nervous system. If GABA receptors are damaged, you would expect to see an increased level of excitation in the nervous system - the opposite of what this patient is reporting.
10001744
c
GABA Receptors
QuestionChoice
Histamine receptors are responsible for vasodilation, bronchoconstriction, and the recruitment of inflammatory cells. Histamine receptors do not affect the skeletal muscles in the body - therefore this is not the correct choice.
10001745
d
Histamine Receptors
QuestionChoice
Serotonin (5-HT) receptors, are G-protein coupled receptors, that are activated by the neurotransmitter serotonin. Serotonin controls neurological processes such as anxiety, appetite, cognition, memory, mood and sleep. This patient is not reporting a change in any of these - this is not the correct answer.
10001743
b
Serotonin (5-HT) Receptors
Concept
Chapter
2693
3968
Myasthenia Gravis
Topic
141
Neurology
12895
A 27-year-old woman presents to General Practice with double vision, difficulty smiling and drooping of both of her eyelids. She is alert and her cognition is intact. She is presenting with the classical symptoms of an autoimmune condition.

Which receptors are being attacked by autoantibodies in this condition?
a