When performing a 12-lead ECG, how many wires are connected to ...

[kfurse]

When performing a 12-lead ECG, how many wires are connected to the patient?
 
  a. 3
  b. 5
  c. 10
  d. 12

Question 2

Considering anatomic location, which cranial nerve will be affected first by downward pressure onto the infratentorial structures?
 
  a. III
  b. VI
  c. IX
  d. X

[ndhahbi]

Answer to Question 1

C
The standard 12-lead electrocardiogram provides a picture of electrical activity in the heart using 10 different electrode positions to create 12 unique views of electrical activity occurring within the heart. Fours wires are applied to the extremities to produce leads I, II, III, aVR, aVL, and aVF. Six wires are attached to the V1 to V6 chest lead positions.

Answer to Question 2

A
With the location of the oculomotor nerve (cranial nerve CN III) at the notch of the tentorium, pupil size and reactivity play a key role in the physical assessment of intracranial pressure changes and herniation syndromes. In addition to CN III compression, changes in pupil size occur for other reasons. Large pupils can result from the instillation of cycloplegic agents, such as atropine or scopolamine, or can indicate extreme stress. Extremely small pupils can indicate narcotic overdose, lower brainstem compression, or bilateral damage to the pons.