Nokea
Proteins that are secreted by cells are generally
- A. not synthesized on membrane-bound ribosomes
- B. initially synthesized with a signal peptide or leader sequence at their C terminal
- C. found in vesicles and secretory granules
- D. moved across the cell membranes by endocytosis
Correct Answer: C
Rationale: Secreted proteins are typically synthesized on membrane-bound ribosomes and transported into the endoplasmic reticulum (ER) via a signal peptide at their N-terminal. They are then packaged into vesicles and secretory granules for transport to the cell membrane and release. Endocytosis is not involved in secretion, and proteins are usually processed (e.g., glycosylated) in the ER and Golgi, but they are not secreted in a larger form than in the ER.
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The 'synaptic cleft' of a neuromuscular junction is
- A. a groove in the muscle cell plasma membrane through which neurons grow
- B. that portion of the cell surface receptor molecule on the surface of a muscle cell, into which the ligand binds
- C. a depression at the end of an axon from which neurotransmitters are secreted
- D. the space between the plasma membrane of a neuron on the pre-synaptic side of the synapse, and the plasma membrane of the muscle cell on the post-synaptic side of the synapse
Correct Answer: D
Rationale: The synaptic cleft is the narrow space between the presynaptic neuron and the postsynaptic muscle cell. It is where neurotransmitters are released and diffuse to bind receptors on the muscle cell, initiating muscle contraction. This structure is essential for signal transmission at the neuromuscular junction.
A patient arrives in the ER with blurred and double vision, muscle weakness, and intolerance of temperature changes. The physician suspects multiple sclerosis. What test would you expect the physician to do in order to confirm his or her suspicions?
- A. CBC with a very low WBC count.
- B. MRI with gadolinium showing demyelination of nerve fibers.
- C. Endocrine function study with a low growth hormone and high T3 and T4.
- D. Fasting glucose test with a result over 300 mg/dL.
Correct Answer: B
Rationale: MRI with gadolinium is used to identify demyelination, which is characteristic of multiple sclerosis.
How do spinal nerves of the peripheral nervous system (PNS) differ from cranial nerves (CNs)?
- A. Only spinal nerves occur in pairs.
- B. CNs affect only the sensory and motor functions of the head and neck.
- C. Cell bodies of all CNs are located in the brain whereas cell bodies of spinal nerves are located in the spinal cord.
- D. All spinal nerves contain both afferent sensory and efferent motor fibers whereas CNs contain one or the other or both.
Correct Answer: D
Rationale: Spinal nerves always contain both sensory and motor fibers, while cranial nerves can vary.
A 58-year-old female, accompanied by her husband, presents with trouble walking. She describes her legs as being heavy and stiff, and at times experiences muscle spasms in her lower extremities. Her husband notices that she has been having trouble writing, and buttoning her shirt. These symptoms have progressively worsened over that past 4-5 months. Neurologic exam is significant for intrinsic hand weakness, and arm fasciculations. The lower extremity is hypertonic, with increased patellar reflexes. On gait testing, the patient has poor balance, moves slowly, and has issues with turning. Which of the following is the best treatment to prolong life?
- A. Pyridostigmine
- B. Botulinum toxin
- C. Prednisone
- D. Riluzole
Correct Answer: D
Rationale: Riluzole is the only FDA-approved medication shown to prolong life in patients with amyotrophic lateral sclerosis (ALS). It works by reducing glutamate-induced excitotoxicity, which is thought to contribute to motor neuron degeneration. Pyridostigmine is used for myasthenia gravis, botulinum toxin for spasticity, prednisone for inflammatory conditions, and intravenous immunoglobulin for autoimmune disorders. None of these treatments have been shown to prolong life in ALS.
In providing care for patients with chronic, progressive neurologic disease, what is the major goal of treatment that the nurse works toward?
- A. Meet the patient's personal care needs.
- B. Return the patient to normal neurologic function.
- C. Maximize neurologic functioning for as long as possible.
- D. Prevent the development of additional chronic diseases.
Correct Answer: C
Rationale: Maximizing function for as long as possible is the primary goal