Nokea
The posterior column transmits which of the following
- A. Afferent pain and temperature
- B. Afferent tendon stretch impulses
- C. Motor tracts
- D. ?
Correct Answer: B
Rationale: The posterior columns (fasciculus gracilis and cuneatus) transmit proprioceptive and fine touch sensations. These pathways are essential for coordination and balance.
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The lateral half of the ankle is supplied by which dermatome
- A. L3
- B. L4
- C. L5
- D. S1
Correct Answer: D
Rationale: The S1 dermatome supplies the lateral aspect of the ankle and foot. This is important in diagnosing sacral nerve root compression.
What is the role of semaphorins and Eph ligands in development of the nervous system?
- A. The semaphorins and Eph ligands are growth factors that stimulate cell division of neurons.
- B. The semaphorins and Eph ligands act as signals for the outgrowth of neuronal growth cones; in general, both lead growth cones to turn away.
- C. The semaphorins and Eph ligands act as signals for the outgrowth of neuronal growth cones; in general, both lead growth cones to come toward them.
- D. The semaphorins and Eph ligands are cell-cell adhesion molecules that bind adjacent neurons together.
Correct Answer: B
Rationale: Semaphorins and Eph ligands act as guidance cues for growing axons. They generally function as repulsive signals, causing growth cones to turn away from inappropriate regions. This ensures precise navigation of axons to their correct targets, which is essential for establishing functional neural circuits.
Mr. K., aged 60 years, has a diagnosis of transient ischemic attack. An essential aspect of his history that needs to be documented is
- A. sudden, brief loss of sensory, motor, or visual function
- B. determining if he has any allergies
- C. any history of neurologic disease
- D. his medication history, both prescribed and over-the-counter
Correct Answer: A
Rationale: Sudden neurological deficits are hallmark symptoms of TIA.
Priority Decision: Twenty-four hours after a below-the-knee amputation, a patient uses the call system to tell the nurse that his dressing (a compression bandage) has fallen off. What is the first action that the nurse should take?
- A. Apply ice to the site.
- B. Cover the incision with dry gauze.
- C. Reapply the compression dressing.
- D. Elevate the extremity on a couple of pillows.
Correct Answer: B
Rationale: Dry gauze protects the wound until proper redressing.
A refractory period is___________.
- A. a brief time when a neuron is unable to conduct an impulse
- B. the period during which potassium and sodium ions are completely stable
- C. the same as the resting potential
- D. the short time the myelin sheath provides insulation from another impulse
Correct Answer: A
Rationale: The refractory period is a brief time following an action potential during which a neuron is unable to fire another impulse. This period ensures that action potentials propagate in one direction and allows the neuron to reset its ion gradients. The refractory period is divided into the absolute refractory period, when no new action potentials can be generated, and the relative refractory period, when a stronger-than-usual stimulus is required to generate an action potential.