Which gland is often abnormal in patients with myasthenia gravis?

Correct Answer: A

Rationale: The thymus gland, which plays a role in immune system development, is often abnormal in patients with myasthenia gravis. Thymic hyperplasia or thymoma is commonly associated with the condition, and thymectomy (surgical removal of the thymus) can improve symptoms in some cases.

Correct Answer: B

Rationale: Synapse is the correct answer because it is the junction between two neurons where electrical or chemical signals are transmitted. Neurotransmitters are the chemicals that facilitate this transmission, but the gap itself is called the synapse.

Correct Answer: D

Rationale: Positive Rinner & Weber test is the correct answer because these tests are used to assess hearing and are not related to cerebellar function. The cerebellum is involved in coordination and balance, so tests like Romberg's, finger-to-nose, and heel-to-knee are used to evaluate cerebellar integrity, while Rinner and Weber tests are auditory assessments.

Correct Answer: D

Rationale: Brown-Sequard syndrome is the correct answer because it is characterized by ipsilateral motor paralysis and loss of proprioception, and contralateral loss of pain and temperature sensation. This syndrome results from damage to one side of the spinal cord, typically due to trauma or tumors.

Correct Answer: A

Rationale: Bulbar palsy is the correct answer because it results from damage to the lower motor neurons of the cranial nerves IX, X, and XII, which are located in the medulla oblongata. This condition leads to dysphagia, dysphonia, dysarthria, and tongue atrophy due to the loss of motor control in the muscles of the pharynx, larynx, and tongue.