ATI LPN
Medical Surgical Nursing Neurological Disorders Questions
Question 1 of 5
Which ion has the greatest electrochemical driving force in a typical neuron with a resting membrane potential of -65 millivolts?
Correct Answer: C
Rationale: The electrochemical driving force (V_DF) for an ion is calculated as V_DF = V_m - V_eq. For sodium, V_eq is +62 mV, so V_DF = -65 - 62 = -127 mV (inward). For potassium, V_eq is -86 mV, so V_DF = +21 mV (outward). For chloride, V_eq is -70 mV, so V_DF = +5 mV (outward). Sodium has the greatest driving force. TMP13 pp. 587-588
Question 2 of 5
Which structure carries axons from neurons in the ventral posterolateral nucleus of the thalamus to the primary somatosensory cortex?
Correct Answer: C
Rationale: The internal capsule conveys axons from the ventral posterolateral nucleus to the somatosensory cortex. TMP13 p. 610
Question 3 of 5
Vibratory sensation depends on the detection of rapidly changing, repetitive sensations. The high-frequency end of the repetitive stimulation scale is detected by which structure?
Correct Answer: C
Rationale: Pacinian corpuscles detect high-frequency vibrations. TMP13 p. 608
Question 4 of 5
Like other sensory systems, the somatosensory system has a descending component that functions to regulate the overall sensitivity of the system. Which of the following selections best describes the function of the corticofugal signals transmitted from the somatosensory cortex downward to the thalamus and dorsal column nuclei?
Correct Answer: A
Rationale: Corticofugal signals modulate signal intensity perception. TMP13 pp. 610-611
Question 5 of 5
Which of the following is the middle ear ossicle that is attached to the tympanic membrane?
Correct Answer: C
Rationale: The malleus attaches to the tympanic membrane. TMP13 p. 673