An older patient who had previously recovered from a heart attack was experiencing slight chest discomfort, dizziness, palpitations and shortness of breath. He was taken to the emergency room via ambulance where an electrocardiogram (ECG) showed increased heart rate (> 100 beats / min) and a long QRS (> 0.12 s). He was diagnosed with wide complex tachycardia with a ventricular origin and properly treated. Which part of his ECG corresponds to atrial repolarization? select one:

a. The QRS duration.
b. None of the options .
c. The T wave.
d. The PR interval.
e. The P wave.

Explain the importance of a proper job attitude.

Ms. b is a 40-year-old woman who is the ceo of a struggling company. lately she has been experiencing headaches that are so severe that she gets dizzy and nauseated, and she is unable to carry out her usual daily routines. she reports that they usually begin as a throbbing pain in the left temple and then seem to spread throughout her head. a diagnosis of migraine headache is made after several tests. based on the patient history and signs and symptoms, discuss this type of headache and its physiological causes. discuss the available treatments to prevent and/or relieve the patient’s migraine.

Feedback mechanisms regulate the rate of enzyme activity, effectively "turning off' an enzyme in a reversible way until more product is needed. which of the following would be most effective as a feedback mechanism? a. reduced concentration of product b. increased concentration of substrate c. a change in ph d. temporary binding of a non-substrate molecule in the active site