Nokea
A nerve fiber obeys an all-or-none law insofar as it either fires or does not fire depending on whether the stimulus is above a threshold.
- A. TRUE
- B. FALSE
Correct Answer: A
Rationale:
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Trigeminal nerve impairment produces the following symptoms:
- A. plegia in half of the face
- B. ache paroxysm in half of the face
- C. disturbance of swallowing
- D. ache in half of the head
Correct Answer: B
Rationale: Ache paroxysm in half of the face is the correct answer because the trigeminal nerve is responsible for sensory innervation of the face and motor control of the muscles of mastication. Damage to this nerve, as seen in trigeminal neuralgia, results in severe, episodic facial pain.
The nurse is caring for a patient who is scheduled for a computed tomography (CT) scan of the brain because of new onset of headaches. Which statement by the nurse is most accurate when preparing the patient for the scan?
- A. You must shampoo your hair thoroughly tonight to remove oil and dirt.
- B. You will need to hold your head completely still during the examination.
- C. You may take fluids until about 8 a.m. Then we will give you a special radiopaque drink.
- D. We will partially shave your head tonight so that electrodes can be attached securely to your scalp.
Correct Answer: B
Rationale: Holding the head still during a CT scan is essential for obtaining clear images. Shampooing the hair, shaving the head, or administering a radiopaque drink are not required for a standard brain CT. Providing accurate instructions ensures the patient is prepared for the procedure.
One of the three basic parts of a neuron is the ________.
- A. axon
- B. myelin
- C. pons
- D. dura mater
Correct Answer: A
Rationale: A neuron consists of three basic parts: the cell body, dendrites, and axon. The axon is a long, slender projection that transmits nerve impulses away from the cell body to other neurons or target cells. Myelin is a protective sheath around some axons, the pons is a part of the brainstem, and the dura mater is a meningeal layer. Therefore, axon is the correct answer as it is one of the fundamental components of a neuron.
The clinical diagnosis of parkinsonism is based on the presence of bradykinesia and at least one of three other features: muscular rigidity, resting tremor, and:
- A. Dystonia
- B. Nystagmus
- C. Postural instability
- D. Seizures
Correct Answer: C
Rationale: Postural instability is a key feature of parkinsonism, along with bradykinesia, rigidity, and resting tremor. It contributes to the risk of falls and mobility issues.
Fibrillations (fasciculations) may develop with disease in:
- A. lateral column of the spinal cord
- B. posterior horn of the spinal cord
- C. anterior horn of the spinal cord
- D. internal capsule
Correct Answer: C
Rationale: Anterior horn of the spinal cord is the correct answer because fibrillations and fasciculations are spontaneous muscle contractions that occur due to the degeneration of lower motor neurons located in the anterior horn. These contractions are a sign of denervation and are commonly seen in conditions like amyotrophic lateral sclerosis (ALS).