A patient comes to the clinic complaining of seasonal rhinitis. What adrenergic agonist will be prescribed for seasonal rhinitis?

A) Monoamine oxidase:
Monoamine oxidase (MAO) is an enzyme, not a neurotransmitter. It is responsible for breaking down certain neurotransmitters, such as dopamine, serotonin, and norepinephrine, in the brain and other parts of the body. While it plays a crucial role in regulating neurotransmitter levels, it is not itself a neurotransmitter.

B) Cholinesterase:
Cholinesterase is also an enzyme, not a neurotransmitter. It breaks down acetylcholine (ACh) at synaptic junctions to terminate its action after it has transmitted a nerve impulse. This enzyme is important for the proper functioning of cholinergic synapses but does not function as a neurotransmitter.

C) Acetylcholine (ACh):
Acetylcholine (ACh) is a neurotransmitter. It is released by nerve cells at cholinergic synapses and plays a key role in both the peripheral and central nervous systems. ACh is involved in transmitting nerve impulses to muscles (muscle contraction) and is also important in cognitive functions like memory and learning in the brain.

D) Calcium:
Calcium is a vital ion involved in many cellular processes, including muscle contraction and neurotransmitter release. However, it is not a neurotransmitter. It plays a role in the function of neurotransmitters but does not act as one itself.

A) Myasthenia gravis (MG):
Weakness of the extremities and diplopia (double vision) are hallmark symptoms of myasthenia gravis, an autoimmune disorder that affects the neuromuscular junction. In MG, antibodies attack acetylcholine receptors, leading to muscle weakness that worsens with activity and improves with rest. The weakness typically affects voluntary muscles, including those responsible for eye movement, which leads to symptoms such as diplopia and ptosis (drooping eyelids).

B) Multiple sclerosis (MS):
Multiple sclerosis involves the demyelination of neurons in the central nervous system, leading to a variety of neurological symptoms. While MS can cause weakness and visual disturbances, the typical symptoms of MS include fatigue, muscle spasticity, ataxia, and sensory deficits. Diplopia can occur in MS but is usually accompanied by other neurological signs such as numbness, tingling, or loss of coordination.

C) Cerebral palsy (CP):
Cerebral palsy is a group of disorders affecting movement and posture due to non-progressive brain injury or abnormal brain development, often occurring in early childhood. While CP can cause muscle weakness and coordination issues, it does not typically present with diplopia. Instead, it often involves spasticity, motor impairment, and difficulty with fine motor tasks.

D) Parkinson disease (PD):
Parkinson disease is characterized by tremors, bradykinesia (slowness of movement), rigidity, and postural instability. While PD can lead to muscle weakness and visual issues like blurred vision, it is not typically associated with diplopia as a primary symptom. The hallmark motor symptoms are primarily related to tremor and difficulty initiating movements rather than generalized weakness and double vision.